Support octet-stream content type in Swagger gen (#372)

This reverts commit 8d275f0047.

.config/dotnet-tools.json

@@ -3,13 +3,13 @@
   "isRoot": true,
   "tools": {
     "fantomas": {
-      "version": "7.0.0",
+      "version": "7.0.1",
       "commands": [
         "fantomas"
       ]
     },
     "fsharp-analyzers": {
-      "version": "0.28.0",
+      "version": "0.30.0",
       "commands": [
         "fsharp-analyzers"
       ]

.github/workflows/dotnet.yaml

@@ -29,7 +29,7 @@ jobs:
       with:
         fetch-depth: 0 # so that NerdBank.GitVersioning has access to history
     - name: Install Nix
-      uses: cachix/install-nix-action@v30
+      uses: cachix/install-nix-action@v31
       with:
         extra_nix_config: |
           access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -50,7 +50,7 @@ jobs:
         with:
           fetch-depth: 0 # so that NerdBank.GitVersioning has access to history
       - name: Install Nix
-        uses: cachix/install-nix-action@v30
+        uses: cachix/install-nix-action@v31
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -67,7 +67,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
       - name: Install Nix
-        uses: cachix/install-nix-action@v30
+        uses: cachix/install-nix-action@v31
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -82,7 +82,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
       - name: Install Nix
-        uses: cachix/install-nix-action@v30
+        uses: cachix/install-nix-action@v31
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -97,7 +97,7 @@ jobs:
         with:
           fetch-depth: 0 # so that NerdBank.GitVersioning has access to history
       - name: Install Nix
-        uses: cachix/install-nix-action@v30
+        uses: cachix/install-nix-action@v31
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -116,7 +116,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
       - name: Install Nix
-        uses: cachix/install-nix-action@v30
+        uses: cachix/install-nix-action@v31
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -129,7 +129,7 @@ jobs:
     steps:
       - uses: actions/checkout@master
       - name: Install Nix
-        uses: cachix/install-nix-action@v30
+        uses: cachix/install-nix-action@v31
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -142,7 +142,7 @@ jobs:
     steps:
       - uses: actions/checkout@master
       - name: Install Nix
-        uses: cachix/install-nix-action@v30
+        uses: cachix/install-nix-action@v31
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -156,7 +156,7 @@ jobs:
       with:
         fetch-depth: 0 # so that NerdBank.GitVersioning has access to history
     - name: Install Nix
-      uses: cachix/install-nix-action@v30
+      uses: cachix/install-nix-action@v31
       with:
         extra_nix_config: |
           access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -254,7 +254,7 @@ jobs:
           name: nuget-package-attribute
           path: packed
       - name: Attest Build Provenance
-        uses: actions/attest-build-provenance@520d128f165991a6c774bcb264f323e3d70747f4 # v2.2.0
+        uses: actions/attest-build-provenance@c074443f1aee8d4aeeae555aebba3282517141b2 # v2.2.3
         with:
           subject-path: "packed/*.nupkg"
 
@@ -273,7 +273,7 @@ jobs:
           name: nuget-package-plugin
           path: packed
       - name: Attest Build Provenance
-        uses: actions/attest-build-provenance@520d128f165991a6c774bcb264f323e3d70747f4 # v2.2.0
+        uses: actions/attest-build-provenance@c074443f1aee8d4aeeae555aebba3282517141b2 # v2.2.3
         with:
           subject-path: "packed/*.nupkg"
 
@@ -289,7 +289,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install Nix
-        uses: cachix/install-nix-action@v30
+        uses: cachix/install-nix-action@v31
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -322,7 +322,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install Nix
-        uses: cachix/install-nix-action@v30
+        uses: cachix/install-nix-action@v31
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}

.github/workflows/flake_update.yaml

@@ -34,7 +34,7 @@ jobs:
 
       - name: Create token
         id: generate-token
-        uses: actions/create-github-app-token@v1
+        uses: actions/create-github-app-token@v2
         with:
           # https://github.com/actions/create-github-app-token/issues/136
           app-id: ${{ secrets.APP_ID }}

CHANGELOG.md

@@ -1,5 +1,27 @@
 Notable changes are recorded here.
 
+# WoofWare.Myriad.Plugins 7.0.1
+
+All generators should now be compatible with `<Nullable>enable</Nullable>`.
+
+**Please test the results and let me know of unexpected failures.**
+There are a number of heuristics in this code, because:
+
+* `System.Text.Json.Nodes` is an unfathomably weird API which simply requires us to make educated guesses about whether a user-provided type is supposed to be nullable, despite this being irrelevant to the operation of `System.Text.Json`;
+* Some types (like `Uri` and `String`) have `ToString` methods which can't return `null`, but in general `Object.ToString` can of course return `null`, and as far as I can tell there is simply no way to know from the source alone whether a given type will have a nullable `ToString`.
+
+# WoofWare.Myriad.Plugins 6.0.1
+
+The `ArgParser` generator's type signatures have changed.
+The `parse'` method no longer takes `getEnvironmentVariable : string -> string`; it's now `getEnvironmentVariable : string -> string option`.
+This is to permit satisfying the `<Nullable>enable</Nullable>` compiler setting.
+If you're calling `parse'`, give it `Environment.GetEnvironmentVariable >> Option.ofObj` instead.
+
+# WoofWare.Myriad.Plugins 5.0.1
+
+We now enforce non-nullability on more types during JSON parse.
+We have always expected you to consume nullable types wrapped in an `option`, but now we enforce this in more cases by throwing `ArgumentNullException`.
+
 # WoofWare.Myriad.Plugins 3.0.1
 
 Semantics of `HttpClient`'s URI component composition changed:

ConsumePlugin/ConsumePlugin.fsproj

@@ -4,6 +4,7 @@
     <TargetFramework>net9.0</TargetFramework>
     <IsPackable>false</IsPackable>
     <OtherFlags>--reflectionfree $(OtherFlags)</OtherFlags>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
     <MyriadSdkGenerator Include="$(MSBuildThisFileDirectory)..\WoofWare.Myriad.Plugins\bin\$(Configuration)\net6.0\WoofWare.Myriad.Plugins.dll"/>

ConsumePlugin/GeneratedArgs.fs

@@ -23,7 +23,7 @@ module BasicNoPositionals =
         /// Waiting to receive a value for the key we've already consumed
         | AwaitingValue of key : string
 
-    let parse' (getEnvironmentVariable : string -> string) (args : string list) : BasicNoPositionals =
+    let parse' (getEnvironmentVariable : string -> string option) (args : string list) : BasicNoPositionals =
         let ArgParser_errors = ResizeArray ()
 
         let helpText () =
@@ -223,7 +223,7 @@ module BasicNoPositionals =
             ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
     let parse (args : string list) : BasicNoPositionals =
-        parse' System.Environment.GetEnvironmentVariable args
+        parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -239,7 +239,7 @@ module Basic =
         /// Waiting to receive a value for the key we've already consumed
         | AwaitingValue of key : string
 
-    let parse' (getEnvironmentVariable : string -> string) (args : string list) : Basic =
+    let parse' (getEnvironmentVariable : string -> string option) (args : string list) : Basic =
         let ArgParser_errors = ResizeArray ()
 
         let helpText () =
@@ -430,7 +430,7 @@ module Basic =
             ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
     let parse (args : string list) : Basic =
-        parse' System.Environment.GetEnvironmentVariable args
+        parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -446,7 +446,7 @@ module BasicWithIntPositionals =
         /// Waiting to receive a value for the key we've already consumed
         | AwaitingValue of key : string
 
-    let parse' (getEnvironmentVariable : string -> string) (args : string list) : BasicWithIntPositionals =
+    let parse' (getEnvironmentVariable : string -> string option) (args : string list) : BasicWithIntPositionals =
         let ArgParser_errors = ResizeArray ()
 
         let helpText () =
@@ -633,7 +633,7 @@ module BasicWithIntPositionals =
             ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
     let parse (args : string list) : BasicWithIntPositionals =
-        parse' System.Environment.GetEnvironmentVariable args
+        parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -649,7 +649,7 @@ module LoadsOfTypes =
         /// Waiting to receive a value for the key we've already consumed
         | AwaitingValue of key : string
 
-    let parse' (getEnvironmentVariable : string -> string) (args : string list) : LoadsOfTypes =
+    let parse' (getEnvironmentVariable : string -> string option) (args : string list) : LoadsOfTypes =
         let ArgParser_errors = ResizeArray ()
 
         let helpText () =
@@ -1038,7 +1038,7 @@ module LoadsOfTypes =
             match arg_10 with
             | None ->
                 match "CONSUMEPLUGIN_THINGS" |> getEnvironmentVariable with
-                | null ->
+                | None ->
                     sprintf
                         "No value was supplied for %s, nor was environment variable %s set"
                         (sprintf "--%s" "yet-another-optional-thing")
@@ -1046,7 +1046,7 @@ module LoadsOfTypes =
                     |> ArgParser_errors.Add
 
                     Unchecked.defaultof<_>
-                | x -> x |> (fun x -> x)
+                | Some x -> x |> (fun x -> x)
                 |> Choice2Of2
             | Some x -> Choice1Of2 x
 
@@ -1068,7 +1068,7 @@ module LoadsOfTypes =
             ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
     let parse (args : string list) : LoadsOfTypes =
-        parse' System.Environment.GetEnvironmentVariable args
+        parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -1084,7 +1084,7 @@ module LoadsOfTypesNoPositionals =
         /// Waiting to receive a value for the key we've already consumed
         | AwaitingValue of key : string
 
-    let parse' (getEnvironmentVariable : string -> string) (args : string list) : LoadsOfTypesNoPositionals =
+    let parse' (getEnvironmentVariable : string -> string option) (args : string list) : LoadsOfTypesNoPositionals =
         let ArgParser_errors = ResizeArray ()
 
         let helpText () =
@@ -1476,7 +1476,7 @@ module LoadsOfTypesNoPositionals =
             match arg_9 with
             | None ->
                 match "CONSUMEPLUGIN_THINGS" |> getEnvironmentVariable with
-                | null ->
+                | None ->
                     sprintf
                         "No value was supplied for %s, nor was environment variable %s set"
                         (sprintf "--%s" "yet-another-optional-thing")
@@ -1484,7 +1484,7 @@ module LoadsOfTypesNoPositionals =
                     |> ArgParser_errors.Add
 
                     Unchecked.defaultof<_>
-                | x -> x |> (fun x -> x)
+                | Some x -> x |> (fun x -> x)
                 |> Choice2Of2
             | Some x -> Choice1Of2 x
 
@@ -1505,7 +1505,7 @@ module LoadsOfTypesNoPositionals =
             ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
     let parse (args : string list) : LoadsOfTypesNoPositionals =
-        parse' System.Environment.GetEnvironmentVariable args
+        parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -1524,7 +1524,7 @@ module DatesAndTimesArgParse =
     /// Extension methods for argument parsing
     type DatesAndTimes with
 
-        static member parse' (getEnvironmentVariable : string -> string) (args : string list) : DatesAndTimes =
+        static member parse' (getEnvironmentVariable : string -> string option) (args : string list) : DatesAndTimes =
             let ArgParser_errors = ResizeArray ()
 
             let helpText () =
@@ -1787,7 +1787,7 @@ module DatesAndTimesArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : DatesAndTimes =
-            DatesAndTimes.parse' System.Environment.GetEnvironmentVariable args
+            DatesAndTimes.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -1806,7 +1806,7 @@ module ParentRecordArgParse =
     /// Extension methods for argument parsing
     type ParentRecord with
 
-        static member parse' (getEnvironmentVariable : string -> string) (args : string list) : ParentRecord =
+        static member parse' (getEnvironmentVariable : string -> string option) (args : string list) : ParentRecord =
             let ArgParser_errors = ResizeArray ()
 
             let helpText () =
@@ -2016,7 +2016,7 @@ module ParentRecordArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : ParentRecord =
-            ParentRecord.parse' System.Environment.GetEnvironmentVariable args
+            ParentRecord.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -2035,7 +2035,11 @@ module ParentRecordChildPosArgParse =
     /// Extension methods for argument parsing
     type ParentRecordChildPos with
 
-        static member parse' (getEnvironmentVariable : string -> string) (args : string list) : ParentRecordChildPos =
+        static member parse'
+            (getEnvironmentVariable : string -> string option)
+            (args : string list)
+            : ParentRecordChildPos
+            =
             let ArgParser_errors = ResizeArray ()
 
             let helpText () =
@@ -2209,7 +2213,7 @@ module ParentRecordChildPosArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : ParentRecordChildPos =
-            ParentRecordChildPos.parse' System.Environment.GetEnvironmentVariable args
+            ParentRecordChildPos.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -2228,7 +2232,11 @@ module ParentRecordSelfPosArgParse =
     /// Extension methods for argument parsing
     type ParentRecordSelfPos with
 
-        static member parse' (getEnvironmentVariable : string -> string) (args : string list) : ParentRecordSelfPos =
+        static member parse'
+            (getEnvironmentVariable : string -> string option)
+            (args : string list)
+            : ParentRecordSelfPos
+            =
             let ArgParser_errors = ResizeArray ()
 
             let helpText () =
@@ -2388,7 +2396,7 @@ module ParentRecordSelfPosArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : ParentRecordSelfPos =
-            ParentRecordSelfPos.parse' System.Environment.GetEnvironmentVariable args
+            ParentRecordSelfPos.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -2407,7 +2415,11 @@ module ChoicePositionalsArgParse =
     /// Extension methods for argument parsing
     type ChoicePositionals with
 
-        static member parse' (getEnvironmentVariable : string -> string) (args : string list) : ChoicePositionals =
+        static member parse'
+            (getEnvironmentVariable : string -> string option)
+            (args : string list)
+            : ChoicePositionals
+            =
             let ArgParser_errors = ResizeArray ()
 
             let helpText () =
@@ -2502,7 +2514,7 @@ module ChoicePositionalsArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : ChoicePositionals =
-            ChoicePositionals.parse' System.Environment.GetEnvironmentVariable args
+            ChoicePositionals.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -2521,7 +2533,11 @@ module ContainsBoolEnvVarArgParse =
     /// Extension methods for argument parsing
     type ContainsBoolEnvVar with
 
-        static member parse' (getEnvironmentVariable : string -> string) (args : string list) : ContainsBoolEnvVar =
+        static member parse'
+            (getEnvironmentVariable : string -> string option)
+            (args : string list)
+            : ContainsBoolEnvVar
+            =
             let ArgParser_errors = ResizeArray ()
 
             let helpText () =
@@ -2653,7 +2669,7 @@ module ContainsBoolEnvVarArgParse =
                 match arg_0 with
                 | None ->
                     match "CONSUMEPLUGIN_THINGS" |> getEnvironmentVariable with
-                    | null ->
+                    | None ->
                         sprintf
                             "No value was supplied for %s, nor was environment variable %s set"
                             (sprintf "--%s" "bool-var")
@@ -2661,7 +2677,7 @@ module ContainsBoolEnvVarArgParse =
                         |> ArgParser_errors.Add
 
                         Unchecked.defaultof<_>
-                    | x ->
+                    | Some x ->
                         if System.String.Equals (x, "1", System.StringComparison.OrdinalIgnoreCase) then
                             true
                         else if System.String.Equals (x, "0", System.StringComparison.OrdinalIgnoreCase) then
@@ -2679,7 +2695,7 @@ module ContainsBoolEnvVarArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : ContainsBoolEnvVar =
-            ContainsBoolEnvVar.parse' System.Environment.GetEnvironmentVariable args
+            ContainsBoolEnvVar.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -2698,7 +2714,7 @@ module WithFlagDuArgParse =
     /// Extension methods for argument parsing
     type WithFlagDu with
 
-        static member parse' (getEnvironmentVariable : string -> string) (args : string list) : WithFlagDu =
+        static member parse' (getEnvironmentVariable : string -> string option) (args : string list) : WithFlagDu =
             let ArgParser_errors = ResizeArray ()
 
             let helpText () =
@@ -2852,7 +2868,7 @@ module WithFlagDuArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : WithFlagDu =
-            WithFlagDu.parse' System.Environment.GetEnvironmentVariable args
+            WithFlagDu.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -2871,7 +2887,11 @@ module ContainsFlagEnvVarArgParse =
     /// Extension methods for argument parsing
     type ContainsFlagEnvVar with
 
-        static member parse' (getEnvironmentVariable : string -> string) (args : string list) : ContainsFlagEnvVar =
+        static member parse'
+            (getEnvironmentVariable : string -> string option)
+            (args : string list)
+            : ContainsFlagEnvVar
+            =
             let ArgParser_errors = ResizeArray ()
 
             let helpText () =
@@ -3018,7 +3038,7 @@ module ContainsFlagEnvVarArgParse =
                 match arg_0 with
                 | None ->
                     match "CONSUMEPLUGIN_THINGS" |> getEnvironmentVariable with
-                    | null ->
+                    | None ->
                         sprintf
                             "No value was supplied for %s, nor was environment variable %s set"
                             (sprintf "--%s" "dry-run")
@@ -3026,7 +3046,7 @@ module ContainsFlagEnvVarArgParse =
                         |> ArgParser_errors.Add
 
                         Unchecked.defaultof<_>
-                    | x ->
+                    | Some x ->
                         if System.String.Equals (x, "1", System.StringComparison.OrdinalIgnoreCase) then
                             if true = Consts.FALSE then
                                 DryRunMode.Wet
@@ -3056,7 +3076,7 @@ module ContainsFlagEnvVarArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : ContainsFlagEnvVar =
-            ContainsFlagEnvVar.parse' System.Environment.GetEnvironmentVariable args
+            ContainsFlagEnvVar.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -3076,7 +3096,7 @@ module ContainsFlagDefaultValueArgParse =
     type ContainsFlagDefaultValue with
 
         static member parse'
-            (getEnvironmentVariable : string -> string)
+            (getEnvironmentVariable : string -> string option)
             (args : string list)
             : ContainsFlagDefaultValue
             =
@@ -3239,7 +3259,7 @@ module ContainsFlagDefaultValueArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : ContainsFlagDefaultValue =
-            ContainsFlagDefaultValue.parse' System.Environment.GetEnvironmentVariable args
+            ContainsFlagDefaultValue.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -3258,7 +3278,7 @@ module ManyLongFormsArgParse =
     /// Extension methods for argument parsing
     type ManyLongForms with
 
-        static member parse' (getEnvironmentVariable : string -> string) (args : string list) : ManyLongForms =
+        static member parse' (getEnvironmentVariable : string -> string option) (args : string list) : ManyLongForms =
             let ArgParser_errors = ResizeArray ()
 
             let helpText () =
@@ -3504,7 +3524,7 @@ module ManyLongFormsArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : ManyLongForms =
-            ManyLongForms.parse' System.Environment.GetEnvironmentVariable args
+            ManyLongForms.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -3524,7 +3544,7 @@ module FlagsIntoPositionalArgsArgParse =
     type FlagsIntoPositionalArgs with
 
         static member parse'
-            (getEnvironmentVariable : string -> string)
+            (getEnvironmentVariable : string -> string option)
             (args : string list)
             : FlagsIntoPositionalArgs
             =
@@ -3668,7 +3688,7 @@ module FlagsIntoPositionalArgsArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : FlagsIntoPositionalArgs =
-            FlagsIntoPositionalArgs.parse' System.Environment.GetEnvironmentVariable args
+            FlagsIntoPositionalArgs.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -3688,7 +3708,7 @@ module FlagsIntoPositionalArgsChoiceArgParse =
     type FlagsIntoPositionalArgsChoice with
 
         static member parse'
-            (getEnvironmentVariable : string -> string)
+            (getEnvironmentVariable : string -> string option)
             (args : string list)
             : FlagsIntoPositionalArgsChoice
             =
@@ -3832,7 +3852,7 @@ module FlagsIntoPositionalArgsChoiceArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : FlagsIntoPositionalArgsChoice =
-            FlagsIntoPositionalArgsChoice.parse' System.Environment.GetEnvironmentVariable args
+            FlagsIntoPositionalArgsChoice.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -3852,7 +3872,7 @@ module FlagsIntoPositionalArgsIntArgParse =
     type FlagsIntoPositionalArgsInt with
 
         static member parse'
-            (getEnvironmentVariable : string -> string)
+            (getEnvironmentVariable : string -> string option)
             (args : string list)
             : FlagsIntoPositionalArgsInt
             =
@@ -3996,7 +4016,7 @@ module FlagsIntoPositionalArgsIntArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : FlagsIntoPositionalArgsInt =
-            FlagsIntoPositionalArgsInt.parse' System.Environment.GetEnvironmentVariable args
+            FlagsIntoPositionalArgsInt.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -4016,7 +4036,7 @@ module FlagsIntoPositionalArgsIntChoiceArgParse =
     type FlagsIntoPositionalArgsIntChoice with
 
         static member parse'
-            (getEnvironmentVariable : string -> string)
+            (getEnvironmentVariable : string -> string option)
             (args : string list)
             : FlagsIntoPositionalArgsIntChoice
             =
@@ -4160,7 +4180,7 @@ module FlagsIntoPositionalArgsIntChoiceArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : FlagsIntoPositionalArgsIntChoice =
-            FlagsIntoPositionalArgsIntChoice.parse' System.Environment.GetEnvironmentVariable args
+            FlagsIntoPositionalArgsIntChoice.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
 namespace ConsumePlugin
 
 open System
@@ -4180,7 +4200,7 @@ module FlagsIntoPositionalArgs'ArgParse =
     type FlagsIntoPositionalArgs' with
 
         static member parse'
-            (getEnvironmentVariable : string -> string)
+            (getEnvironmentVariable : string -> string option)
             (args : string list)
             : FlagsIntoPositionalArgs'
             =
@@ -4324,4 +4344,4 @@ module FlagsIntoPositionalArgs'ArgParse =
                 ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
 
         static member parse (args : string list) : FlagsIntoPositionalArgs' =
-            FlagsIntoPositionalArgs'.parse' System.Environment.GetEnvironmentVariable args
+            FlagsIntoPositionalArgs'.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args

ConsumePlugin/GeneratedJson.fs

@@ -14,7 +14,24 @@ module internal InternalTypeNotExtensionSerial =
     /// Serialize to a JSON node
     let toJsonNode (input : InternalTypeNotExtensionSerial) : System.Text.Json.Nodes.JsonNode =
         let node = System.Text.Json.Nodes.JsonObject ()
-        do node.Add ((Literals.something), (input.InternalThing2 |> System.Text.Json.Nodes.JsonValue.Create<string>))
+
+        do
+            node.Add (
+                (Literals.something),
+                (input.InternalThing2
+                 |> (fun field ->
+                     let field = System.Text.Json.Nodes.JsonValue.Create<string> field
+
+                     (match field with
+                      | null ->
+                          raise (
+                              System.ArgumentNullException
+                                  "Expected type string to be non-null, but received a null value when serialising"
+                          )
+                      | field -> field)
+                 ))
+            )
+
         node :> _
 namespace ConsumePlugin
 
@@ -29,7 +46,24 @@ module internal InternalTypeExtensionJsonSerializeExtension =
         /// Serialize to a JSON node
         static member toJsonNode (input : InternalTypeExtension) : System.Text.Json.Nodes.JsonNode =
             let node = System.Text.Json.Nodes.JsonObject ()
-            do node.Add ((Literals.something), (input.ExternalThing |> System.Text.Json.Nodes.JsonValue.Create<string>))
+
+            do
+                node.Add (
+                    (Literals.something),
+                    (input.ExternalThing
+                     |> (fun field ->
+                         let field = System.Text.Json.Nodes.JsonValue.Create<string> field
+
+                         (match field with
+                          | null ->
+                              raise (
+                                  System.ArgumentNullException
+                                      "Expected type string to be non-null, but received a null value when serialising"
+                              )
+                          | field -> field)
+                     ))
+                )
+
             node :> _
 
 namespace ConsumePlugin
@@ -40,16 +74,14 @@ module InnerType =
     /// Parse from a JSON node.
     let jsonParse (node : System.Text.Json.Nodes.JsonNode) : InnerType =
         let arg_0 =
-            (match node.[(Literals.something)] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ((Literals.something))
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.String> ()
+            match node.[(Literals.something)] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ((Literals.something))
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.String> ()
 
         {
             Thing = arg_0
@@ -62,79 +94,97 @@ module JsonRecordType =
     /// Parse from a JSON node.
     let jsonParse (node : System.Text.Json.Nodes.JsonNode) : JsonRecordType =
         let arg_5 =
-            (match node.["f"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("f")
-                     )
-                 )
-             | v -> v)
-                .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.Int32> ())
-            |> Array.ofSeq
+            match node.["f"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("f")
+                    )
+                )
+            | Some node ->
+                node.AsArray ()
+                |> Seq.map (fun elt ->
+                    (match elt with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected element of array (element type int32) to be non-null, but found a null element"
+                         )
+                     | elt -> elt.AsValue().GetValue<System.Int32> ())
+                )
+                |> Array.ofSeq
 
         let arg_4 =
-            (match node.["e"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("e")
-                     )
-                 )
-             | v -> v)
-                .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.String> ())
-            |> Array.ofSeq
+            match node.["e"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("e")
+                    )
+                )
+            | Some node ->
+                node.AsArray ()
+                |> Seq.map (fun elt ->
+                    (match elt with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected element of array (element type string) to be non-null, but found a null element"
+                         )
+                     | elt -> elt.AsValue().GetValue<System.String> ())
+                )
+                |> Array.ofSeq
 
         let arg_3 =
-            InnerType.jsonParse (
-                match node.["d"] with
-                | null ->
-                    raise (
-                        System.Collections.Generic.KeyNotFoundException (
-                            sprintf "Required key '%s' not found on JSON object" ("d")
-                        )
+            match node.["d"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("d")
                     )
-                | v -> v
-            )
+                )
+            | Some node -> InnerType.jsonParse node
 
         let arg_2 =
-            (match node.["hi"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("hi")
-                     )
-                 )
-             | v -> v)
-                .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.Int32> ())
-            |> List.ofSeq
+            match node.["hi"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("hi")
+                    )
+                )
+            | Some node ->
+                node.AsArray ()
+                |> Seq.map (fun elt ->
+                    (match elt with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected element of array (element type int32) to be non-null, but found a null element"
+                         )
+                     | elt -> elt.AsValue().GetValue<System.Int32> ())
+                )
+                |> List.ofSeq
 
         let arg_1 =
-            (match node.["another-thing"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("another-thing")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.String> ()
+            match node.["another-thing"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("another-thing")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.String> ()
 
         let arg_0 =
-            (match node.["a"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("a")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.Int32> ()
+            match node.["a"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("a")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.Int32> ()
 
         {
             A = arg_0
@@ -152,16 +202,14 @@ module internal InternalTypeNotExtension =
     /// Parse from a JSON node.
     let jsonParse (node : System.Text.Json.Nodes.JsonNode) : InternalTypeNotExtension =
         let arg_0 =
-            (match node.[(Literals.something)] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ((Literals.something))
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.String> ()
+            match node.[(Literals.something)] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ((Literals.something))
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.String> ()
 
         {
             InternalThing = arg_0
@@ -177,16 +225,14 @@ module internal InternalTypeExtensionJsonParseExtension =
         /// Parse from a JSON node.
         static member jsonParse (node : System.Text.Json.Nodes.JsonNode) : InternalTypeExtension =
             let arg_0 =
-                (match node.[(Literals.something)] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ((Literals.something))
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.String> ()
+                match node.[(Literals.something)] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ((Literals.something))
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.String> ()
 
             {
                 ExternalThing = arg_0
@@ -201,248 +247,215 @@ module ToGetExtensionMethodJsonParseExtension =
 
         /// Parse from a JSON node.
         static member jsonParse (node : System.Text.Json.Nodes.JsonNode) : ToGetExtensionMethod =
-            let arg_20 = System.Numerics.BigInteger.Parse (node.["whiskey"].ToJsonString ())
+            let arg_20 =
+                match node.["whiskey"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("whiskey")
+                        )
+                    )
+                | Some node -> System.Numerics.BigInteger.Parse (node.ToJsonString ())
 
             let arg_19 =
-                (match node.["victor"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("victor")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.Char> ()
+                match node.["victor"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("victor")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.Char> ()
 
             let arg_18 =
-                (match node.["uniform"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("uniform")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.Decimal> ()
+                match node.["uniform"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("uniform")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.Decimal> ()
 
             let arg_17 =
-                (match node.["tango"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("tango")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.SByte> ()
+                match node.["tango"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("tango")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.SByte> ()
 
             let arg_16 =
-                (match node.["quebec"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("quebec")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.Byte> ()
+                match node.["quebec"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("quebec")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.Byte> ()
 
             let arg_15 =
-                (match node.["papa"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("papa")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.Byte> ()
+                match node.["papa"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("papa")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.Byte> ()
 
             let arg_14 =
-                (match node.["oscar"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("oscar")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.SByte> ()
+                match node.["oscar"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("oscar")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.SByte> ()
 
             let arg_13 =
-                (match node.["november"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("november")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.UInt16> ()
+                match node.["november"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("november")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.UInt16> ()
 
             let arg_12 =
-                (match node.["mike"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("mike")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.Int16> ()
+                match node.["mike"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("mike")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.Int16> ()
 
             let arg_11 =
-                (match node.["lima"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("lima")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.UInt32> ()
+                match node.["lima"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("lima")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.UInt32> ()
 
             let arg_10 =
-                (match node.["kilo"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("kilo")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.Int32> ()
+                match node.["kilo"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("kilo")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.Int32> ()
 
             let arg_9 =
-                (match node.["juliette"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("juliette")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.UInt32> ()
+                match node.["juliette"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("juliette")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.UInt32> ()
 
             let arg_8 =
-                (match node.["india"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("india")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.Int32> ()
+                match node.["india"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("india")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.Int32> ()
 
             let arg_7 =
-                (match node.["hotel"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("hotel")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.UInt64> ()
+                match node.["hotel"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("hotel")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.UInt64> ()
 
             let arg_6 =
-                (match node.["golf"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("golf")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.Int64> ()
+                match node.["golf"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("golf")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.Int64> ()
 
             let arg_5 =
-                (match node.["foxtrot"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("foxtrot")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.Double> ()
+                match node.["foxtrot"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("foxtrot")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.Double> ()
 
             let arg_4 =
-                (match node.["echo"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("echo")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.Single> ()
+                match node.["echo"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("echo")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.Single> ()
 
             let arg_3 =
-                (match node.["delta"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("delta")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.Single> ()
+                match node.["delta"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("delta")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.Single> ()
 
             let arg_2 =
-                (match node.["charlie"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("charlie")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.Double> ()
+                match node.["charlie"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("charlie")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.Double> ()
 
             let arg_1 =
-                (match node.["bravo"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("bravo")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<string> ()
-                |> System.Uri
+                match node.["bravo"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("bravo")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<string> () |> System.Uri
 
             let arg_0 =
-                (match node.["alpha"] with
-                 | null ->
-                     raise (
-                         System.Collections.Generic.KeyNotFoundException (
-                             sprintf "Required key '%s' not found on JSON object" ("alpha")
-                         )
-                     )
-                 | v -> v)
-                    .AsValue()
-                    .GetValue<System.String> ()
+                match node.["alpha"] |> Option.ofObj with
+                | None ->
+                    raise (
+                        System.Collections.Generic.KeyNotFoundException (
+                            sprintf "Required key '%s' not found on JSON object" ("alpha")
+                        )
+                    )
+                | Some node -> node.AsValue().GetValue<System.String> ()
 
             {
                 Alpha = arg_0

ConsumePlugin/GeneratedRestClient.fs

@@ -48,7 +48,27 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
-                    return jsonNode.AsArray () |> Seq.map (fun elt -> Gym.jsonParse elt) |> List.ofSeq
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type Gym list"
+                             )
+                         | jsonNode -> jsonNode)
+
+                    return
+                        jsonNode.AsArray ()
+                        |> Seq.map (fun elt ->
+                            (match elt with
+                             | null ->
+                                 raise (
+                                     System.ArgumentNullException
+                                         "Expected element of array (element type Gym) to be non-null, but found a null element"
+                                 )
+                             | elt -> Gym.jsonParse elt)
+                        )
+                        |> List.ofSeq
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
 
@@ -82,6 +102,15 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type GymAttendance"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return GymAttendance.jsonParse jsonNode
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -116,6 +145,15 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type GymAttendance"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return GymAttendance.jsonParse jsonNode
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -146,6 +184,15 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type Member"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return Member.jsonParse jsonNode
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -179,6 +226,15 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type Gym"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return Gym.jsonParse jsonNode
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -209,6 +265,15 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type MemberActivityDto"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return MemberActivityDto.jsonParse jsonNode
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -239,6 +304,15 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type UriThing"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return UriThing.jsonParse jsonNode
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -266,23 +340,42 @@ module PureGymApi =
                             foo
                             |> (fun field ->
                                 match field with
-                                | None -> null :> System.Text.Json.Nodes.JsonNode
+                                | None -> None
                                 | Some field ->
-                                    ((fun field ->
-                                        let ret = System.Text.Json.Nodes.JsonObject ()
+                                    (field
+                                     |> (fun field ->
+                                         let ret = System.Text.Json.Nodes.JsonObject ()
 
-                                        for (KeyValue (key, value)) in field do
-                                            ret.Add (
-                                                key.ToString (),
-                                                System.Text.Json.Nodes.JsonValue.Create<string> value
-                                            )
+                                         for (KeyValue (key, value)) in field do
+                                             let key = key.ToString ()
 
-                                        ret
-                                    )
-                                        field)
+                                             ret.Add (
+                                                 key,
+                                                 (fun field ->
+                                                     let field =
+                                                         System.Text.Json.Nodes.JsonValue.Create<string> field
+
+                                                     (match field with
+                                                      | null ->
+                                                          raise (
+                                                              System.ArgumentNullException
+                                                                  "Expected type string to be non-null, but received a null value when serialising"
+                                                          )
+                                                      | field -> field)
+                                                 )
+                                                     value
+                                             )
+
+                                         ret
+                                     ))
                                     :> System.Text.Json.Nodes.JsonNode
+                                    |> Some
+                            )
+                            |> (fun node ->
+                                match node with
+                                | None -> "null"
+                                | Some node -> node.ToJsonString ()
                             )
-                            |> (fun node -> if isNull node then "null" else node.ToJsonString ())
                         )
 
                     do httpMessage.Content <- queryParams
@@ -294,15 +387,25 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode = jsonNode |> Option.ofObj
+
                     return
                         match jsonNode with
-                        | null -> None
-                        | v ->
+                        | None -> None
+                        | Some v ->
                             v.AsObject ()
                             |> Seq.map (fun kvp ->
                                 let key = (kvp.Key)
-                                let value = (kvp.Value).AsValue().GetValue<System.String> ()
-                                key, value
+                                let value = kvp.Value
+
+                                key,
+                                (match value with
+                                 | null ->
+                                     raise (
+                                         System.ArgumentNullException
+                                             "Expected dictionary value of type string to be non-null, but it was null"
+                                     )
+                                 | value -> value.AsValue().GetValue<System.String> ())
                             )
                             |> Map.ofSeq
                             |> Some
@@ -346,6 +449,15 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type Sessions"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return Sessions.jsonParse jsonNode
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -387,6 +499,15 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type Sessions"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return Sessions.jsonParse jsonNode
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -546,9 +667,7 @@ module PureGymApi =
 
                     let queryParams =
                         new System.Net.Http.StringContent (
-                            user
-                            |> PureGym.Member.toJsonNode
-                            |> (fun node -> if isNull node then "null" else node.ToJsonString ())
+                            user |> PureGym.Member.toJsonNode |> (fun node -> node.ToJsonString ())
                         )
 
                     do httpMessage.Content <- queryParams
@@ -580,8 +699,18 @@ module PureGymApi =
                     let queryParams =
                         new System.Net.Http.StringContent (
                             user
-                            |> System.Text.Json.Nodes.JsonValue.Create<Uri>
-                            |> (fun node -> if isNull node then "null" else node.ToJsonString ())
+                            |> (fun field ->
+                                let field = System.Text.Json.Nodes.JsonValue.Create<Uri> field
+
+                                (match field with
+                                 | null ->
+                                     raise (
+                                         System.ArgumentNullException
+                                             "Expected type URI to be non-null, but received a null value when serialising"
+                                     )
+                                 | field -> field)
+                            )
+                            |> (fun node -> node.ToJsonString ())
                         )
 
                     do httpMessage.Content <- queryParams
@@ -613,8 +742,18 @@ module PureGymApi =
                     let queryParams =
                         new System.Net.Http.StringContent (
                             user
-                            |> System.Text.Json.Nodes.JsonValue.Create<int>
-                            |> (fun node -> if isNull node then "null" else node.ToJsonString ())
+                            |> (fun field ->
+                                let field = System.Text.Json.Nodes.JsonValue.Create<int> field
+
+                                (match field with
+                                 | null ->
+                                     raise (
+                                         System.ArgumentNullException
+                                             "Expected type int32 to be non-null, but received a null value when serialising"
+                                     )
+                                 | field -> field)
+                            )
+                            |> (fun node -> node.ToJsonString ())
                         )
 
                     do httpMessage.Content <- queryParams
@@ -878,6 +1017,15 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type Response<MemberActivityDto>"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return
                         new RestEase.Response<_> (
                             responseString,
@@ -914,6 +1062,15 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type RestEase.Response<MemberActivityDto>"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return
                         new RestEase.Response<_> (
                             responseString,
@@ -950,6 +1107,15 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type Response<MemberActivityDto>"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return
                         new RestEase.Response<_> (
                             responseString,
@@ -986,6 +1152,15 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type RestEase.Response<MemberActivityDto>"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return
                         new RestEase.Response<_> (
                             responseString,

ConsumePlugin/GeneratedVault.fs

@@ -13,139 +13,147 @@ module JwtVaultAuthResponse =
     /// Parse from a JSON node.
     let jsonParse (node : System.Text.Json.Nodes.JsonNode) : JwtVaultAuthResponse =
         let arg_10 =
-            (match node.["num_uses"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("num_uses")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.Int32> ()
+            match node.["num_uses"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("num_uses")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.Int32> ()
 
         let arg_9 =
-            (match node.["orphan"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("orphan")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.Boolean> ()
+            match node.["orphan"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("orphan")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.Boolean> ()
 
         let arg_8 =
-            (match node.["entity_id"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("entity_id")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.String> ()
+            match node.["entity_id"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("entity_id")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.String> ()
 
         let arg_7 =
-            (match node.["token_type"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("token_type")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.String> ()
+            match node.["token_type"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("token_type")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.String> ()
 
         let arg_6 =
-            (match node.["renewable"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("renewable")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.Boolean> ()
+            match node.["renewable"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("renewable")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.Boolean> ()
 
         let arg_5 =
-            (match node.["lease_duration"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("lease_duration")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.Int32> ()
+            match node.["lease_duration"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("lease_duration")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.Int32> ()
 
         let arg_4 =
-            (match node.["identity_policies"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("identity_policies")
-                     )
-                 )
-             | v -> v)
-                .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.String> ())
-            |> List.ofSeq
+            match node.["identity_policies"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("identity_policies")
+                    )
+                )
+            | Some node ->
+                node.AsArray ()
+                |> Seq.map (fun elt ->
+                    (match elt with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected element of array (element type string) to be non-null, but found a null element"
+                         )
+                     | elt -> elt.AsValue().GetValue<System.String> ())
+                )
+                |> List.ofSeq
 
         let arg_3 =
-            (match node.["token_policies"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("token_policies")
-                     )
-                 )
-             | v -> v)
-                .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.String> ())
-            |> List.ofSeq
+            match node.["token_policies"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("token_policies")
+                    )
+                )
+            | Some node ->
+                node.AsArray ()
+                |> Seq.map (fun elt ->
+                    (match elt with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected element of array (element type string) to be non-null, but found a null element"
+                         )
+                     | elt -> elt.AsValue().GetValue<System.String> ())
+                )
+                |> List.ofSeq
 
         let arg_2 =
-            (match node.["policies"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("policies")
-                     )
-                 )
-             | v -> v)
-                .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.String> ())
-            |> List.ofSeq
+            match node.["policies"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("policies")
+                    )
+                )
+            | Some node ->
+                node.AsArray ()
+                |> Seq.map (fun elt ->
+                    (match elt with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected element of array (element type string) to be non-null, but found a null element"
+                         )
+                     | elt -> elt.AsValue().GetValue<System.String> ())
+                )
+                |> List.ofSeq
 
         let arg_1 =
-            (match node.["accessor"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("accessor")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.String> ()
+            match node.["accessor"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("accessor")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.String> ()
 
         let arg_0 =
-            (match node.["client_token"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("client_token")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.String> ()
+            match node.["client_token"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("client_token")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.String> ()
 
         {
             ClientToken = arg_0
@@ -168,64 +176,54 @@ module JwtVaultResponse =
     /// Parse from a JSON node.
     let jsonParse (node : System.Text.Json.Nodes.JsonNode) : JwtVaultResponse =
         let arg_4 =
-            JwtVaultAuthResponse.jsonParse (
-                match node.["auth"] with
-                | null ->
-                    raise (
-                        System.Collections.Generic.KeyNotFoundException (
-                            sprintf "Required key '%s' not found on JSON object" ("auth")
-                        )
+            match node.["auth"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("auth")
                     )
-                | v -> v
-            )
+                )
+            | Some node -> JwtVaultAuthResponse.jsonParse node
 
         let arg_3 =
-            (match node.["lease_duration"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("lease_duration")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.Int32> ()
+            match node.["lease_duration"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("lease_duration")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.Int32> ()
 
         let arg_2 =
-            (match node.["renewable"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("renewable")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.Boolean> ()
+            match node.["renewable"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("renewable")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.Boolean> ()
 
         let arg_1 =
-            (match node.["lease_id"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("lease_id")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.String> ()
+            match node.["lease_id"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("lease_id")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.String> ()
 
         let arg_0 =
-            (match node.["request_id"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("request_id")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.String> ()
+            match node.["request_id"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("request_id")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.String> ()
 
         {
             RequestId = arg_0
@@ -242,190 +240,246 @@ module JwtSecretResponse =
     /// Parse from a JSON node.
     let jsonParse (node : System.Text.Json.Nodes.JsonNode) : JwtSecretResponse =
         let arg_11 =
-            (match node.["data8"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("data8")
-                     )
-                 )
-             | v -> v)
-                .AsObject ()
-            |> Seq.map (fun kvp ->
-                let key = (kvp.Key)
-                let value = (kvp.Value).AsValue().GetValue<string> () |> System.Uri
-                key, value
-            )
-            |> Seq.map System.Collections.Generic.KeyValuePair
-            |> System.Collections.Generic.Dictionary
+            match node.["data8"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("data8")
+                    )
+                )
+            | Some node ->
+                node.AsObject ()
+                |> Seq.map (fun kvp ->
+                    let key = (kvp.Key)
+                    let value = kvp.Value
+
+                    key,
+                    (match value with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected dictionary value of type URI to be non-null, but it was null"
+                         )
+                     | value -> value.AsValue().GetValue<string> () |> System.Uri)
+                )
+                |> Seq.map System.Collections.Generic.KeyValuePair
+                |> System.Collections.Generic.Dictionary
 
         let arg_10 =
-            (match node.["data7"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("data7")
-                     )
-                 )
-             | v -> v)
-                .AsObject ()
-            |> Seq.map (fun kvp ->
-                let key = (kvp.Key)
-                let value = (kvp.Value).AsValue().GetValue<System.Int32> ()
-                key, value
-            )
-            |> Map.ofSeq
+            match node.["data7"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("data7")
+                    )
+                )
+            | Some node ->
+                node.AsObject ()
+                |> Seq.map (fun kvp ->
+                    let key = (kvp.Key)
+                    let value = kvp.Value
+
+                    key,
+                    (match value with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected dictionary value of type int32 to be non-null, but it was null"
+                         )
+                     | value -> value.AsValue().GetValue<System.Int32> ())
+                )
+                |> Map.ofSeq
 
         let arg_9 =
-            (match node.["data6"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("data6")
-                     )
-                 )
-             | v -> v)
-                .AsObject ()
-            |> Seq.map (fun kvp ->
-                let key = (kvp.Key) |> System.Uri
-                let value = (kvp.Value).AsValue().GetValue<System.String> ()
-                key, value
-            )
-            |> dict
+            match node.["data6"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("data6")
+                    )
+                )
+            | Some node ->
+                node.AsObject ()
+                |> Seq.map (fun kvp ->
+                    let key = (kvp.Key) |> System.Uri
+                    let value = kvp.Value
+
+                    key,
+                    (match value with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected dictionary value of type string to be non-null, but it was null"
+                         )
+                     | value -> value.AsValue().GetValue<System.String> ())
+                )
+                |> dict
 
         let arg_8 =
-            (match node.["data5"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("data5")
-                     )
-                 )
-             | v -> v)
-                .AsObject ()
-            |> Seq.map (fun kvp ->
-                let key = (kvp.Key) |> System.Uri
-                let value = (kvp.Value).AsValue().GetValue<System.String> ()
-                key, value
-            )
-            |> readOnlyDict
+            match node.["data5"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("data5")
+                    )
+                )
+            | Some node ->
+                node.AsObject ()
+                |> Seq.map (fun kvp ->
+                    let key = (kvp.Key) |> System.Uri
+                    let value = kvp.Value
+
+                    key,
+                    (match value with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected dictionary value of type string to be non-null, but it was null"
+                         )
+                     | value -> value.AsValue().GetValue<System.String> ())
+                )
+                |> readOnlyDict
 
         let arg_7 =
-            (match node.["data4"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("data4")
-                     )
-                 )
-             | v -> v)
-                .AsObject ()
-            |> Seq.map (fun kvp ->
-                let key = (kvp.Key)
-                let value = (kvp.Value).AsValue().GetValue<System.String> ()
-                key, value
-            )
-            |> Map.ofSeq
+            match node.["data4"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("data4")
+                    )
+                )
+            | Some node ->
+                node.AsObject ()
+                |> Seq.map (fun kvp ->
+                    let key = (kvp.Key)
+                    let value = kvp.Value
+
+                    key,
+                    (match value with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected dictionary value of type string to be non-null, but it was null"
+                         )
+                     | value -> value.AsValue().GetValue<System.String> ())
+                )
+                |> Map.ofSeq
 
         let arg_6 =
-            (match node.["data3"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("data3")
-                     )
-                 )
-             | v -> v)
-                .AsObject ()
-            |> Seq.map (fun kvp ->
-                let key = (kvp.Key)
-                let value = (kvp.Value).AsValue().GetValue<System.String> ()
-                key, value
-            )
-            |> Seq.map System.Collections.Generic.KeyValuePair
-            |> System.Collections.Generic.Dictionary
+            match node.["data3"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("data3")
+                    )
+                )
+            | Some node ->
+                node.AsObject ()
+                |> Seq.map (fun kvp ->
+                    let key = (kvp.Key)
+                    let value = kvp.Value
+
+                    key,
+                    (match value with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected dictionary value of type string to be non-null, but it was null"
+                         )
+                     | value -> value.AsValue().GetValue<System.String> ())
+                )
+                |> Seq.map System.Collections.Generic.KeyValuePair
+                |> System.Collections.Generic.Dictionary
 
         let arg_5 =
-            (match node.["data2"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("data2")
-                     )
-                 )
-             | v -> v)
-                .AsObject ()
-            |> Seq.map (fun kvp ->
-                let key = (kvp.Key)
-                let value = (kvp.Value).AsValue().GetValue<System.String> ()
-                key, value
-            )
-            |> dict
+            match node.["data2"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("data2")
+                    )
+                )
+            | Some node ->
+                node.AsObject ()
+                |> Seq.map (fun kvp ->
+                    let key = (kvp.Key)
+                    let value = kvp.Value
+
+                    key,
+                    (match value with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected dictionary value of type string to be non-null, but it was null"
+                         )
+                     | value -> value.AsValue().GetValue<System.String> ())
+                )
+                |> dict
 
         let arg_4 =
-            (match node.["data"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("data")
-                     )
-                 )
-             | v -> v)
-                .AsObject ()
-            |> Seq.map (fun kvp ->
-                let key = (kvp.Key)
-                let value = (kvp.Value).AsValue().GetValue<System.String> ()
-                key, value
-            )
-            |> readOnlyDict
+            match node.["data"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("data")
+                    )
+                )
+            | Some node ->
+                node.AsObject ()
+                |> Seq.map (fun kvp ->
+                    let key = (kvp.Key)
+                    let value = kvp.Value
+
+                    key,
+                    (match value with
+                     | null ->
+                         raise (
+                             System.ArgumentNullException
+                                 "Expected dictionary value of type string to be non-null, but it was null"
+                         )
+                     | value -> value.AsValue().GetValue<System.String> ())
+                )
+                |> readOnlyDict
 
         let arg_3 =
-            (match node.["lease_duration"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("lease_duration")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.Int32> ()
+            match node.["lease_duration"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("lease_duration")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.Int32> ()
 
         let arg_2 =
-            (match node.["renewable"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("renewable")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.Boolean> ()
+            match node.["renewable"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("renewable")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.Boolean> ()
 
         let arg_1 =
-            (match node.["lease_id"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("lease_id")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.String> ()
+            match node.["lease_id"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("lease_id")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.String> ()
 
         let arg_0 =
-            (match node.["request_id"] with
-             | null ->
-                 raise (
-                     System.Collections.Generic.KeyNotFoundException (
-                         sprintf "Required key '%s' not found on JSON object" ("request_id")
-                     )
-                 )
-             | v -> v)
-                .AsValue()
-                .GetValue<System.String> ()
+            match node.["request_id"] |> Option.ofObj with
+            | None ->
+                raise (
+                    System.Collections.Generic.KeyNotFoundException (
+                        sprintf "Required key '%s' not found on JSON object" ("request_id")
+                    )
+                )
+            | Some node -> node.AsValue().GetValue<System.String> ()
 
         {
             RequestId = arg_0
@@ -496,6 +550,15 @@ module VaultClient =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type JwtSecretResponse"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return JwtSecretResponse.jsonParse jsonNode
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -532,6 +595,15 @@ module VaultClient =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type JwtVaultResponse"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return JwtVaultResponse.jsonParse jsonNode
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -590,6 +662,15 @@ module VaultClientNonExtensionMethod =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type JwtSecretResponse"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return JwtSecretResponse.jsonParse jsonNode
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -626,6 +707,15 @@ module VaultClientNonExtensionMethod =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
+                    let jsonNode =
+                        (match jsonNode with
+                         | null ->
+                             raise (
+                                 System.ArgumentNullException
+                                     "Response from server was the JSON null object; expected a non-nullable type JwtVaultResponse"
+                             )
+                         | jsonNode -> jsonNode)
+
                     return JwtVaultResponse.jsonParse jsonNode
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -687,6 +777,15 @@ module VaultClientExtensionMethodHttpClientExtension =
                             System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                             |> Async.AwaitTask
 
+                        let jsonNode =
+                            (match jsonNode with
+                             | null ->
+                                 raise (
+                                     System.ArgumentNullException
+                                         "Response from server was the JSON null object; expected a non-nullable type JwtSecretResponse"
+                                 )
+                             | jsonNode -> jsonNode)
+
                         return JwtSecretResponse.jsonParse jsonNode
                     }
                     |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
@@ -723,6 +822,15 @@ module VaultClientExtensionMethodHttpClientExtension =
                             System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                             |> Async.AwaitTask
 
+                        let jsonNode =
+                            (match jsonNode with
+                             | null ->
+                                 raise (
+                                     System.ArgumentNullException
+                                         "Response from server was the JSON null object; expected a non-nullable type JwtVaultResponse"
+                                 )
+                             | jsonNode -> jsonNode)
+
                         return JwtVaultResponse.jsonParse jsonNode
                     }
                     |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))

Directory.Build.props

@@ -10,7 +10,7 @@
     <WarnOn>FS3388,FS3559</WarnOn>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Nerdbank.GitVersioning" Version="3.7.115" PrivateAssets="all"/>
+    <PackageReference Include="Nerdbank.GitVersioning" Version="3.8.38-alpha" PrivateAssets="all"/>
     <SourceLinkGitHubHost Include="github.com" ContentUrl="https://raw.githubusercontent.com"/>
   </ItemGroup>
   <PropertyGroup Condition="'$(GITHUB_ACTION)' != ''">

WoofWare.Myriad.Plugins.Attributes/ArgParserAttributes.fs

@@ -26,6 +26,11 @@ type ArgParserAttribute (isExtensionMethod : bool) =
 /// an argument which looks like a flag but which we don't recognise.)
 /// We will still interpret `--help` as requesting help, unless it comes after
 /// a standalone `--` separator.
+///
+/// If the type of the PositionalArgs field is `Choice<'a, 'a>`, then we will
+/// tell you whether each arg came before or after a standalone `--` separator.
+/// For example, `MyApp foo bar -- baz` with PositionalArgs of `Choice<string, string>`
+/// would yield `Choice1Of2 foo, Choice1Of2 bar, Choice2Of2 baz`.
 type PositionalArgsAttribute (includeFlagLike : bool) =
     inherit Attribute ()
 

WoofWare.Myriad.Plugins.Attributes/Test/WoofWare.Myriad.Plugins.Attributes.Test.fsproj

@@ -17,10 +17,10 @@
     </ItemGroup>
 
     <ItemGroup>
-        <PackageReference Include="ApiSurface" Version="4.1.16" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0"/>
+        <PackageReference Include="ApiSurface" Version="4.1.20" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.13.0"/>
         <PackageReference Include="NUnit" Version="4.3.2"/>
-        <PackageReference Include="NUnit3TestAdapter" Version="4.6.0"/>
+        <PackageReference Include="NUnit3TestAdapter" Version="5.0.0"/>
     </ItemGroup>
 
     <ItemGroup>

WoofWare.Myriad.Plugins.Test/TestArgParser/TestArgParser.fs

@@ -68,7 +68,7 @@ module TestArgParser =
 
         let getEnvVar (_ : string) =
             Interlocked.Increment envCalls |> ignore<int>
-            ""
+            None
 
         let args = [ "--foo=3" ; "--non-existent" ; "--bar=4" ; "--baz=true" ]
 
@@ -91,7 +91,7 @@ module TestArgParser =
 
         let getEnvVar (_ : string) =
             Interlocked.Increment envCalls |> ignore<int>
-            ""
+            None
 
         let property (args : (int * bool) list) (afterDoubleDash : int list option) =
             let flatArgs =
@@ -127,7 +127,7 @@ module TestArgParser =
 
         let getEnvVar (_ : string) =
             Interlocked.Increment envCalls |> ignore<int>
-            ""
+            None
 
         let args = [ "--foo=3" ; "--rest" ; "7" ; "--bar=4" ; "--baz=true" ; "--rest=8" ]
 
@@ -150,7 +150,7 @@ module TestArgParser =
 
         let getEnvVar (_ : string) =
             Interlocked.Increment envCalls |> ignore<int>
-            ""
+            None
 
         let args = [ "--foo=3" ; "--foo" ; "9" ; "--bar=4" ; "--baz=true" ; "--baz=false" ]
 
@@ -171,7 +171,7 @@ Argument '--baz' was supplied multiple times: True and false"""
 
         let getEnvVar (_ : string) =
             Interlocked.Increment envCalls |> ignore<int>
-            ""
+            None
 
         let args = [ "--" ; "--foo=3" ; "--bar=4" ; "--baz=true" ]
 
@@ -191,7 +191,7 @@ Required argument '--baz' received no value"""
     let ``Help text`` () =
         let getEnvVar (s : string) =
             s |> shouldEqual "CONSUMEPLUGIN_THINGS"
-            "hi!"
+            Some "hi!"
 
         let exc =
             Assert.Throws<exn> (fun () -> Basic.parse' getEnvVar [ "--help" ] |> ignore<Basic>)
@@ -210,7 +210,7 @@ Required argument '--baz' received no value"""
 
         let getEnvVar (_ : string) =
             Interlocked.Increment envVars |> ignore<int>
-            ""
+            None
 
         let exc =
             Assert.Throws<exn> (fun () -> LoadsOfTypes.parse' getEnvVar [ "--help" ] |> ignore<LoadsOfTypes>)
@@ -236,7 +236,7 @@ Required argument '--baz' received no value"""
     let ``Default values`` () =
         let getEnvVar (s : string) =
             s |> shouldEqual "CONSUMEPLUGIN_THINGS"
-            "hi!"
+            Some "hi!"
 
         let args =
             [
@@ -264,7 +264,7 @@ Required argument '--baz' received no value"""
 
         let getEnvVar (_ : string) =
             Interlocked.Increment count |> ignore<int>
-            ""
+            None
 
         let exc =
             Assert.Throws<exn> (fun () -> DatesAndTimes.parse' getEnvVar [ "--help" ] |> ignore<DatesAndTimes>)
@@ -285,7 +285,7 @@ Required argument '--baz' received no value"""
 
         let getEnvVar (_ : string) =
             Interlocked.Increment count |> ignore<int>
-            ""
+            None
 
         let parsed =
             DatesAndTimes.parse'
@@ -448,7 +448,7 @@ Required argument '--exact' received no value"""
     let ``Bool env vars can be populated`` (envValue : string, boolValue : bool) =
         let getEnvVar (s : string) =
             s |> shouldEqual "CONSUMEPLUGIN_THINGS"
-            envValue
+            Some envValue
 
         ContainsBoolEnvVar.parse' getEnvVar []
         |> shouldEqual
@@ -470,7 +470,7 @@ Required argument '--exact' received no value"""
     let ``Flag DUs can be parsed from env var`` (envValue : string, boolValue : bool) =
         let getEnvVar (s : string) =
             s |> shouldEqual "CONSUMEPLUGIN_THINGS"
-            envValue
+            Some envValue
 
         let boolValue = if boolValue then DryRunMode.Dry else DryRunMode.Wet
 

WoofWare.Myriad.Plugins.Test/WoofWare.Myriad.Plugins.Test.fsproj

@@ -9,6 +9,7 @@
       I have not yet seen a single instance where I care about this warning
     -->
     <NoWarn>$(NoWarn),NU1903</NoWarn>
+    <TestingPlatformDotnetTestSupport>true</TestingPlatformDotnetTestSupport>
   </PropertyGroup>
 
   <ItemGroup>
@@ -41,12 +42,12 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="ApiSurface" Version="4.1.16"/>
-    <PackageReference Include="FsCheck" Version="3.1.0"/>
-    <PackageReference Include="FsUnit" Version="6.0.1"/>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0"/>
+    <PackageReference Include="ApiSurface" Version="4.1.20"/>
+    <PackageReference Include="FsCheck" Version="3.2.0"/>
+    <PackageReference Include="FsUnit" Version="7.0.1"/>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.13.0"/>
     <PackageReference Include="NUnit" Version="4.3.2"/>
-    <PackageReference Include="NUnit3TestAdapter" Version="4.6.0"/>
+    <PackageReference Include="NUnit3TestAdapter" Version="5.0.0"/>
   </ItemGroup>
 
   <ItemGroup>

WoofWare.Myriad.Plugins/ArgParserGenerator.fs

@@ -673,7 +673,7 @@ module internal ArgParserGenerator =
                 args
                 |> Map.toList
                 |> List.map (fun (ident, expr) -> SynLongIdent.create [ Ident.create ident ], expr)
-                |> AstHelper.instantiateRecord
+                |> SynExpr.createRecord None
             )
 
         tree, counter
@@ -1396,7 +1396,7 @@ module internal ArgParserGenerator =
 
                             [
                                 SynMatchClause.create
-                                    SynPat.createNull
+                                    (SynPat.named "None")
                                     (SynExpr.sequential
                                         [
                                             errorMessage
@@ -1406,7 +1406,7 @@ module internal ArgParserGenerator =
                                             unchecked
                                         ])
 
-                                SynMatchClause.create (SynPat.named "x") parser
+                                SynMatchClause.create (SynPat.nameWithArgs "Some" [ SynPat.named "x" ]) parser
                             ]
                             |> SynExpr.createMatch result
                         | ArgumentDefaultSpec.FunctionCall name ->
@@ -1694,7 +1694,7 @@ module internal ArgParserGenerator =
                     [ Ident.create "parse'" ]
                     [
                         SynPat.named "getEnvironmentVariable"
-                        |> SynPat.annotateType (SynType.funFromDomain SynType.string SynType.string)
+                        |> SynPat.annotateType (SynType.funFromDomain SynType.string (SynType.option SynType.string))
                         argsParam
                     ]
                 |> SynBinding.withReturnAnnotation (SynType.createLongIdent [ taggedType.Name ])
@@ -1708,7 +1708,12 @@ module internal ArgParserGenerator =
 
             let parse =
                 SynExpr.createLongIdent' parsePrimeCall
-                |> SynExpr.applyTo (SynExpr.createLongIdent [ "System" ; "Environment" ; "GetEnvironmentVariable" ])
+                |> SynExpr.applyTo (
+                    SynExpr.paren (
+                        SynExpr.createLongIdent [ "System" ; "Environment" ; "GetEnvironmentVariable" ]
+                        |> SynExpr.composeWith (SynExpr.createLongIdent [ "Option" ; "ofObj" ])
+                    )
+                )
                 |> SynExpr.applyTo (SynExpr.createIdent "args")
                 |> SynBinding.basic [ Ident.create "parse" ] [ argsParam ]
                 |> SynBinding.withReturnAnnotation (SynType.createLongIdent [ taggedType.Name ])

WoofWare.Myriad.Plugins/AstHelper.fs

@@ -36,13 +36,6 @@ module internal AstHelper =
         | SynTypeDefnRepr.Simple (SynTypeDefnSimpleRepr.Enum _, _) -> true
         | _ -> false
 
-    let instantiateRecord (fields : (SynLongIdent * SynExpr) list) : SynExpr =
-        let fields =
-            fields
-            |> List.map (fun (rfn, synExpr) -> SynExprRecordField ((rfn, true), Some range0, Some synExpr, None))
-
-        SynExpr.Record (None, None, fields, range0)
-
     let defineRecordType (record : RecordType) : SynTypeDefn =
         let name =
             SynComponentInfo.create record.Name

WoofWare.Myriad.Plugins/HttpClientGenerator.fs

@@ -1,6 +1,5 @@
 namespace WoofWare.Myriad.Plugins
 
-open System.IO
 open System.Net.Http
 open Fantomas.FCS.Syntax
 open WoofWare.Whippet.Fantomas
@@ -14,17 +13,6 @@ type internal HttpClientGeneratorOutputSpec =
 module internal HttpClientGenerator =
     open Fantomas.FCS.Text.Range
 
-    let outputFile = FileInfo "/tmp/output.txt"
-
-    // do
-    //     use _ = File.Create outputFile.FullName
-    //     ()
-
-    let log (line : string) =
-        // use w = outputFile.AppendText ()
-        // w.WriteLine line
-        ()
-
     [<RequireQualifiedAccess>]
     type PathSpec =
         | Verbatim of string
@@ -409,30 +397,59 @@ module internal HttpClientGenerator =
             | String -> SynExpr.createIdent "responseString"
             | Stream -> SynExpr.createIdent "responseStream"
             | RestEaseResponseType contents ->
-                let deserialiser =
-                    JsonParseGenerator.parseNode
+                match JsonNodeWithNullability.Identify contents with
+                | CannotBeNull ->
+                    let deserialiser =
+                        JsonParseGenerator.parseNonNullableNode
+                            None
+                            JsonParseGenerator.JsonParseOption.None
+                            contents
+                            (SynExpr.createIdent "jsonNode")
+                        |> SynExpr.paren
+                        |> SynExpr.createThunk
+
+                    // new RestEase.Response (content : string, response : HttpResponseMessage, deserialiser : unit -> 'T)
+                    SynExpr.createNew
+                        (SynType.app' (SynType.createLongIdent' [ "RestEase" ; "Response" ]) [ SynType.Anon range0 ])
+                        (SynExpr.tupleNoParen
+                            [
+                                SynExpr.createIdent "responseString"
+                                SynExpr.createIdent "response"
+                                deserialiser
+                            ])
+                | Nullable ->
+                    let deserialiser =
+                        JsonParseGenerator.parseNullableNode
+                            None
+                            JsonParseGenerator.JsonParseOption.None
+                            contents
+                            (SynExpr.createIdent "jsonNode")
+                        |> SynExpr.paren
+                        |> SynExpr.createThunk
+
+                    // new RestEase.Response (content : string, response : HttpResponseMessage, deserialiser : unit -> 'T)
+                    SynExpr.createNew
+                        (SynType.app' (SynType.createLongIdent' [ "RestEase" ; "Response" ]) [ SynType.Anon range0 ])
+                        (SynExpr.tupleNoParen
+                            [
+                                SynExpr.createIdent "responseString"
+                                SynExpr.createIdent "response"
+                                deserialiser
+                            ])
+            | retType ->
+                match JsonNodeWithNullability.Identify retType with
+                | Nullable ->
+                    JsonParseGenerator.parseNullableNode
                         None
                         JsonParseGenerator.JsonParseOption.None
-                        contents
+                        retType
+                        (SynExpr.createIdent "jsonNode")
+                | CannotBeNull ->
+                    JsonParseGenerator.parseNonNullableNode
+                        None
+                        JsonParseGenerator.JsonParseOption.None
+                        retType
                         (SynExpr.createIdent "jsonNode")
-                    |> SynExpr.paren
-                    |> SynExpr.createThunk
-
-                // new RestEase.Response (content : string, response : HttpResponseMessage, deserialiser : unit -> 'T)
-                SynExpr.createNew
-                    (SynType.app' (SynType.createLongIdent' [ "RestEase" ; "Response" ]) [ SynType.Anon range0 ])
-                    (SynExpr.tupleNoParen
-                        [
-                            SynExpr.createIdent "responseString"
-                            SynExpr.createIdent "response"
-                            deserialiser
-                        ])
-            | retType ->
-                JsonParseGenerator.parseNode
-                    None
-                    JsonParseGenerator.JsonParseOption.None
-                    retType
-                    (SynExpr.createIdent "jsonNode")
 
         let contentTypeHeader, memberHeaders =
             info.Headers
@@ -505,23 +522,45 @@ module internal HttpClientGenerator =
                         )
                     ]
                 | BodyParamMethods.Serialise ty ->
+                    let isNullable =
+                        match JsonNodeWithNullability.Identify ty with
+                        | CannotBeNull -> false
+                        | Nullable -> true
+
                     [
                         Let (
                             "queryParams",
                             createStringContent (
                                 SynExpr.createIdent' bodyParamName
-                                |> SynExpr.pipeThroughFunction (fst (JsonSerializeGenerator.serializeNode ty))
+                                |> SynExpr.pipeThroughFunction (
+                                    fst (
+                                        (if isNullable then
+                                             JsonSerializeGenerator.serializeNodeNullable
+                                         else
+                                             JsonSerializeGenerator.serializeNodeNonNullable)
+                                            ty
+                                    )
+                                )
                                 |> SynExpr.pipeThroughFunction (
                                     SynExpr.createLambda
                                         "node"
-                                        (SynExpr.ifThenElse
-                                            (SynExpr.applyFunction
-                                                (SynExpr.createIdent "isNull")
-                                                (SynExpr.createIdent "node"))
-                                            (SynExpr.applyFunction
-                                                (SynExpr.createLongIdent [ "node" ; "ToJsonString" ])
-                                                (SynExpr.CreateConst ()))
-                                            (SynExpr.CreateConst "null"))
+                                        (if isNullable then
+                                             SynExpr.createMatch
+                                                 (SynExpr.createIdent "node")
+                                                 [
+                                                     SynMatchClause.create
+                                                         (SynPat.named "None")
+                                                         (SynExpr.CreateConst "null")
+                                                     SynMatchClause.create
+                                                         (SynPat.nameWithArgs "Some" [ SynPat.named "node" ])
+                                                         (SynExpr.applyFunction
+                                                             (SynExpr.createLongIdent [ "node" ; "ToJsonString" ])
+                                                             (SynExpr.CreateConst ()))
+                                                 ]
+                                         else
+                                             (SynExpr.applyFunction
+                                                 (SynExpr.createLongIdent [ "node" ; "ToJsonString" ])
+                                                 (SynExpr.CreateConst ())))
                                 )
                             )
                         )
@@ -568,6 +607,24 @@ module internal HttpClientGenerator =
                     )
                 )
 
+            let jsonNodeWithoutNull =
+                match JsonNodeWithNullability.Identify info.TaskReturnType with
+                | Nullable ->
+                    Let (
+                        "jsonNode",
+                        SynExpr.createIdent "jsonNode"
+                        |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "Option" ; "ofObj" ])
+                    )
+                | CannotBeNull ->
+                    Let (
+                        "jsonNode",
+                        JsonSerializeGenerator.assertNotNull
+                            (Ident.create "jsonNode")
+                            (SynExpr.CreateConst
+                                $"Response from server was the JSON null object; expected a non-nullable type %s{SynType.toHumanReadableString info.TaskReturnType}")
+                            (SynExpr.createIdent "jsonNode")
+                    )
+
             let setVariableHeaders =
                 variableHeaders
                 |> List.map (fun (headerName, callToGetValue) ->
@@ -642,6 +699,7 @@ module internal HttpClientGenerator =
                     yield responseString
                     yield responseStream
                     yield jsonNode
+                    yield jsonNodeWithoutNull
                 | String -> yield responseString
                 | Stream -> yield responseStream
                 | UnitType ->
@@ -650,6 +708,7 @@ module internal HttpClientGenerator =
                 | _ ->
                     yield responseStream
                     yield jsonNode
+                    yield jsonNodeWithoutNull
             ]
             |> SynExpr.createCompExpr "async" returnExpr
             |> SynExpr.startAsTask cancellationTokenArg

WoofWare.Myriad.Plugins/InterfaceMockGenerator.fs

@@ -89,7 +89,7 @@ module internal InterfaceMockGenerator =
                      []
                  else
                      [ SynPat.unit ])
-                (AstHelper.instantiateRecord constructorFields)
+                (SynExpr.createRecord None constructorFields)
             |> SynBinding.withXmlDoc (PreXmlDoc.create "An implementation where every method throws.")
             |> SynBinding.withReturnAnnotation constructorReturnType
             |> SynMemberDefn.staticMember

WoofWare.Myriad.Plugins/JsonParseGenerator.fs

@@ -26,7 +26,7 @@ module internal JsonParseGenerator =
             }
 
     /// (match {indexed} with | null -> raise (System.Collections.Generic.KeyNotFoundException ({propertyName} not found)) | v -> v)
-    let assertNotNull (propertyName : SynExpr) (indexed : SynExpr) =
+    let assertPropertyExists (propertyName : SynExpr) (indexed : SynExpr) =
         let raiseExpr =
             SynExpr.applyFunction
                 (SynExpr.createIdent "sprintf")
@@ -40,34 +40,34 @@ module internal JsonParseGenerator =
             |> SynExpr.applyFunction (SynExpr.createIdent "raise")
 
         [
-            SynMatchClause.create SynPat.createNull raiseExpr
-            SynMatchClause.create (SynPat.named "v") (SynExpr.createIdent "v")
+            SynMatchClause.create (SynPat.named "None") raiseExpr
+            SynMatchClause.create (SynPat.nameWithArgs "Some" [ SynPat.named "v" ]) (SynExpr.createIdent "v")
         ]
         |> SynExpr.createMatch indexed
         |> SynExpr.paren
 
     /// {node}.AsValue().GetValue<{typeName}> ()
-    /// If `propertyName` is Some, uses `assertNotNull {node}` instead of `{node}`.
+    /// If `propertyName` is Some, uses `assertPropertyExists {node}` instead of `{node}`.
     let asValueGetValue (propertyName : SynExpr option) (typeName : string) (node : SynExpr) : SynExpr =
         match propertyName with
         | None -> node
-        | Some propertyName -> assertNotNull propertyName node
+        | Some propertyName -> assertPropertyExists propertyName node
         |> SynExpr.callMethod "AsValue"
         |> SynExpr.callGenericMethod' "GetValue" typeName
 
     let asValueGetValueIdent (propertyName : SynExpr option) (typeName : LongIdent) (node : SynExpr) : SynExpr =
         match propertyName with
         | None -> node
-        | Some propertyName -> assertNotNull propertyName node
+        | Some propertyName -> assertPropertyExists propertyName node
         |> SynExpr.callMethod "AsValue"
         |> SynExpr.callGenericMethod (SynLongIdent.createS "GetValue") [ SynType.createLongIdent typeName ]
 
     /// {node}.AsObject()
-    /// If `propertyName` is Some, uses `assertNotNull {node}` instead of `{node}`.
+    /// If `propertyName` is Some, uses `assertPropertyExists {node}` instead of `{node}`.
     let asObject (propertyName : SynExpr option) (node : SynExpr) : SynExpr =
         match propertyName with
         | None -> node
-        | Some propertyName -> assertNotNull propertyName node
+        | Some propertyName -> assertPropertyExists propertyName node
         |> SynExpr.callMethod "AsObject"
 
     /// {type}.jsonParse {node}
@@ -77,11 +77,12 @@ module internal JsonParseGenerator =
 
     /// collectionType is e.g. "List"; we'll be calling `ofSeq` on it.
     /// body is the body of a lambda which takes a parameter `elt`.
-    /// {assertNotNull node}.AsArray()
-    /// |> Seq.map (fun elt -> {body})
+    /// {assertPropertyExists node}.AsArray()
+    /// |> Seq.map (fun elt -> {assertNotNull} {body})
     /// |> {collectionType}.ofSeq
     let asArrayMapped
         (propertyName : SynExpr option)
+        (elementType : SynType)
         (collectionType : string)
         (node : SynExpr)
         (body : SynExpr)
@@ -89,10 +90,23 @@ module internal JsonParseGenerator =
         =
         match propertyName with
         | None -> node
-        | Some propertyName -> assertNotNull propertyName node
+        | Some propertyName -> assertPropertyExists propertyName node
         |> SynExpr.callMethod "AsArray"
         |> SynExpr.pipeThroughFunction (
-            SynExpr.applyFunction (SynExpr.createLongIdent [ "Seq" ; "map" ]) (SynExpr.createLambda "elt" body)
+            body
+            |> JsonSerializeGenerator.assertNotNull
+                (Ident.create "elt")
+                (match propertyName with
+                 | None ->
+                     SynExpr.CreateConst
+                         $"Expected element of array (element type %s{SynType.toHumanReadableString elementType}) to be non-null, but found a null element"
+                 | Some propertyName ->
+                     SynExpr.CreateConst
+                         $"Expected element of array (element type %s{SynType.toHumanReadableString elementType}) to be non-null, but found a null element, at %%s"
+                     |> SynExpr.applyFunction (SynExpr.createIdent "sprintf")
+                     |> SynExpr.applyTo propertyName)
+            |> SynExpr.createLambda "elt"
+            |> SynExpr.applyFunction (SynExpr.createLongIdent [ "Seq" ; "map" ])
         )
         |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ collectionType ; "ofSeq" ])
 
@@ -101,14 +115,41 @@ module internal JsonParseGenerator =
 
     /// fun kvp -> let key = {key(kvp)} in let value = {value(kvp)} in (key, value))
     /// The inputs will be fed with appropriate SynExprs to apply them to the `kvp.Key` and `kvp.Value` args.
-    let dictionaryMapper (key : SynExpr -> SynExpr) (value : SynExpr -> SynExpr) : SynExpr =
+    let dictionaryMapper
+        (propertyName : SynExpr option)
+        (valueTypeIsNullable : bool)
+        (key : SynExpr -> SynExpr)
+        (valueType : SynType)
+        (value : SynExpr -> SynExpr)
+        : SynExpr
+        =
         let keyArg = SynExpr.createLongIdent [ "kvp" ; "Key" ] |> SynExpr.paren
 
-        let valueArg = SynExpr.createLongIdent [ "kvp" ; "Value" ] |> SynExpr.paren
+        let valueArg = SynExpr.createLongIdent [ "kvp" ; "Value" ]
+
+        let value =
+            if valueTypeIsNullable then
+                (value (SynExpr.createIdent "value"))
+            else
+                let errorMessage =
+                    match propertyName with
+                    | None ->
+                        SynExpr.CreateConst
+                            $"Expected dictionary value of type %s{SynType.toHumanReadableString valueType} to be non-null, but it was null"
+                    | Some propertyName ->
+                        SynExpr.CreateConst
+                            $"Expected dictionary value of type %s{SynType.toHumanReadableString valueType} to be non-null, but it was null, at key %%s"
+                        |> SynExpr.applyFunction (SynExpr.createIdent "sprintf")
+                        |> SynExpr.applyTo propertyName
+
+                JsonSerializeGenerator.assertNotNull
+                    (Ident.create "value")
+                    errorMessage
+                    (value (SynExpr.createIdent "value"))
 
         // No need to paren here, we're on the LHS of a `let`
-        SynExpr.tupleNoParen [ SynExpr.createIdent "key" ; SynExpr.createIdent "value" ]
-        |> SynExpr.createLet [ SynBinding.basic [ Ident.create "value" ] [] (value valueArg) ]
+        SynExpr.tupleNoParen [ SynExpr.createIdent "key" ; value ]
+        |> SynExpr.createLet [ SynBinding.basic [ Ident.create "value" ] [] valueArg ]
         |> SynExpr.createLet [ SynBinding.basic [ Ident.create "key" ] [] (key keyArg) ]
         |> SynExpr.createLambda "kvp"
 
@@ -165,10 +206,61 @@ module internal JsonParseGenerator =
                 ))
                 handler
 
+    let rec parseNullableNode
+        // TODO: unused?!
+        (propertyName : SynExpr option)
+        (options : JsonParseOption)
+        (fieldType : SynType)
+        (node : SynExpr)
+        : SynExpr
+        =
+        match fieldType with
+        | OptionType ty ->
+            match ty with
+            | OptionType _
+            | NullableType _ ->
+                failwith
+                    $"Nested nullable types are not supported, because we can't distinguish between None and Some None. %s{SynType.toHumanReadableString ty}"
+            | _ ->
+
+            let someClause =
+                parseNonNullableNode None options ty (SynExpr.createIdent "v")
+                |> SynExpr.pipeThroughFunction (SynExpr.createIdent "Some")
+                |> SynMatchClause.create (SynPat.nameWithArgs "Some" [ SynPat.named "v" ])
+
+            [
+                SynMatchClause.create (SynPat.named "None") (SynExpr.createIdent "None")
+                someClause
+            ]
+            |> SynExpr.createMatch node
+        | NullableType ty ->
+            match ty with
+            | OptionType _
+            | NullableType _ ->
+                failwith
+                    $"Nested nullable types are not supported, because we can't distinguish between None and Some None. %s{SynType.toHumanReadableString ty}"
+            | _ ->
+
+            let someClause =
+                parseNonNullableNode None options ty (SynExpr.createIdent "v")
+                |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "Nullable" ])
+                |> SynMatchClause.create (SynPat.nameWithArgs "Some" [ SynPat.named "v" ])
+
+            [
+                SynMatchClause.create
+                    (SynPat.named "None")
+                    (SynExpr.applyFunction (SynExpr.createLongIdent [ "System" ; "Nullable" ]) (SynExpr.CreateConst ()))
+                someClause
+            ]
+            |> SynExpr.createMatch node
+        | _ ->
+            failwith
+                $"Encountered type %s{SynType.toHumanReadableString fieldType} which is expected to be nullable, but couldn't identify it"
+
     /// Given `node.["town"]`, for example, choose how to obtain a JSON value from it.
     /// The property name is used in error messages at runtime to show where a JSON
     /// parse error occurred; supply `None` to indicate "don't validate".
-    let rec parseNode
+    and parseNonNullableNode
         (propertyName : SynExpr option)
         (options : JsonParseOption)
         (fieldType : SynType)
@@ -177,101 +269,184 @@ module internal JsonParseGenerator =
         =
         // TODO: parsing format for DateTime etc
         match fieldType with
+        | OptionType _
+        | NullableType _ ->
+            failwith
+                $"Unexpectedly parsing nullable type %s{SynType.toHumanReadableString fieldType} as if it were non-nullable."
+        // Struct types
         | DateOnly ->
             node
             |> asValueGetValue propertyName "string"
             |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "DateOnly" ; "Parse" ])
-        | Uri ->
-            node
-            |> asValueGetValue propertyName "string"
-            |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "Uri" ])
-        | Guid ->
-            node
-            |> asValueGetValue propertyName "string"
-            |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "Guid" ; "Parse" ])
         | DateTime ->
             node
             |> asValueGetValue propertyName "string"
             |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "DateTime" ; "Parse" ])
+        | NumberType typeName -> parseNumberType options propertyName node typeName
+        | Guid ->
+            node
+            |> asValueGetValue propertyName "string"
+            |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "Guid" ; "Parse" ])
+        // Reference types
+        | Uri ->
+            node
+            |> asValueGetValue propertyName "string"
+            |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "Uri" ])
         | DateTimeOffset ->
             node
             |> asValueGetValue propertyName "string"
             |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "DateTimeOffset" ; "Parse" ])
-        | NumberType typeName -> parseNumberType options propertyName node typeName
         | PrimitiveType typeName -> asValueGetValueIdent propertyName typeName node
-        | OptionType ty ->
-            let someClause =
-                parseNode None options ty (SynExpr.createIdent "v")
-                |> SynExpr.pipeThroughFunction (SynExpr.createIdent "Some")
-                |> SynMatchClause.create (SynPat.named "v")
-
-            [
-                SynMatchClause.create SynPat.createNull (SynExpr.createIdent "None")
-                someClause
-            ]
-            |> SynExpr.createMatch node
-        | NullableType ty ->
-            let someClause =
-                parseNode None options ty (SynExpr.createIdent "v")
-                |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "Nullable" ])
-                |> SynMatchClause.create (SynPat.named "v")
-
-            [
-                SynMatchClause.create
-                    SynPat.createNull
-                    (SynExpr.applyFunction (SynExpr.createLongIdent [ "System" ; "Nullable" ]) (SynExpr.CreateConst ()))
-                someClause
-            ]
-            |> SynExpr.createMatch node
         | ListType ty ->
-            parseNode None options ty (SynExpr.createIdent "elt")
-            |> asArrayMapped propertyName "List" node
+            match JsonNodeWithNullability.Identify ty with
+            | CannotBeNull ->
+                parseNonNullableNode None options ty (SynExpr.createIdent "elt")
+                |> asArrayMapped propertyName ty "List" node
+            | Nullable ->
+                parseNullableNode None options ty (SynExpr.createIdent "elt")
+                |> asArrayMapped propertyName ty "List" node
         | ArrayType ty ->
-            parseNode None options ty (SynExpr.createIdent "elt")
-            |> asArrayMapped propertyName "Array" node
+            match JsonNodeWithNullability.Identify ty with
+            | CannotBeNull ->
+                parseNonNullableNode None options ty (SynExpr.createIdent "elt")
+                |> asArrayMapped propertyName ty "Array" node
+            | Nullable ->
+                parseNullableNode None options ty (SynExpr.createIdent "elt")
+                |> asArrayMapped propertyName ty "Array" node
         | IDictionaryType (keyType, valueType) ->
-            node
-            |> asObject propertyName
-            |> SynExpr.pipeThroughFunction (
-                SynExpr.applyFunction
-                    (SynExpr.createLongIdent [ "Seq" ; "map" ])
-                    (dictionaryMapper (parseKeyString keyType) (parseNode None options valueType))
-            )
-            |> SynExpr.pipeThroughFunction (SynExpr.createIdent "dict")
+            match JsonNodeWithNullability.Identify valueType with
+            | CannotBeNull ->
+                node
+                |> asObject propertyName
+                |> SynExpr.pipeThroughFunction (
+                    SynExpr.applyFunction
+                        (SynExpr.createLongIdent [ "Seq" ; "map" ])
+                        (dictionaryMapper
+                            propertyName
+                            false
+                            (parseKeyString keyType)
+                            valueType
+                            (parseNonNullableNode None options valueType))
+                )
+                |> SynExpr.pipeThroughFunction (SynExpr.createIdent "dict")
+            | Nullable ->
+                node
+                |> asObject propertyName
+                |> SynExpr.pipeThroughFunction (
+                    SynExpr.applyFunction
+                        (SynExpr.createLongIdent [ "Seq" ; "map" ])
+                        (dictionaryMapper
+                            propertyName
+                            true
+                            (parseKeyString keyType)
+                            valueType
+                            (parseNullableNode None options valueType))
+                )
+                |> SynExpr.pipeThroughFunction (SynExpr.createIdent "dict")
         | DictionaryType (keyType, valueType) ->
-            node
-            |> asObject propertyName
-            |> SynExpr.pipeThroughFunction (
-                SynExpr.applyFunction
-                    (SynExpr.createLongIdent [ "Seq" ; "map" ])
-                    (dictionaryMapper (parseKeyString keyType) (parseNode None options valueType))
-            )
-            |> SynExpr.pipeThroughFunction (
-                SynExpr.applyFunction
-                    (SynExpr.createLongIdent [ "Seq" ; "map" ])
-                    (SynExpr.createLongIdent [ "System" ; "Collections" ; "Generic" ; "KeyValuePair" ])
-            )
-            |> SynExpr.pipeThroughFunction (
-                SynExpr.createLongIdent [ "System" ; "Collections" ; "Generic" ; "Dictionary" ]
-            )
+            match JsonNodeWithNullability.Identify valueType with
+            | CannotBeNull ->
+                node
+                |> asObject propertyName
+                |> SynExpr.pipeThroughFunction (
+                    SynExpr.applyFunction
+                        (SynExpr.createLongIdent [ "Seq" ; "map" ])
+                        (dictionaryMapper
+                            propertyName
+                            false
+                            (parseKeyString keyType)
+                            valueType
+                            (parseNonNullableNode None options valueType))
+                )
+                |> SynExpr.pipeThroughFunction (
+                    SynExpr.applyFunction
+                        (SynExpr.createLongIdent [ "Seq" ; "map" ])
+                        (SynExpr.createLongIdent [ "System" ; "Collections" ; "Generic" ; "KeyValuePair" ])
+                )
+                |> SynExpr.pipeThroughFunction (
+                    SynExpr.createLongIdent [ "System" ; "Collections" ; "Generic" ; "Dictionary" ]
+                )
+            | Nullable ->
+                node
+                |> asObject propertyName
+                |> SynExpr.pipeThroughFunction (
+                    SynExpr.applyFunction
+                        (SynExpr.createLongIdent [ "Seq" ; "map" ])
+                        (dictionaryMapper
+                            propertyName
+                            true
+                            (parseKeyString keyType)
+                            valueType
+                            (parseNullableNode None options valueType))
+                )
+                |> SynExpr.pipeThroughFunction (
+                    SynExpr.applyFunction
+                        (SynExpr.createLongIdent [ "Seq" ; "map" ])
+                        (SynExpr.createLongIdent [ "System" ; "Collections" ; "Generic" ; "KeyValuePair" ])
+                )
+                |> SynExpr.pipeThroughFunction (
+                    SynExpr.createLongIdent [ "System" ; "Collections" ; "Generic" ; "Dictionary" ]
+                )
         | IReadOnlyDictionaryType (keyType, valueType) ->
-            node
-            |> asObject propertyName
-            |> SynExpr.pipeThroughFunction (
-                SynExpr.applyFunction
-                    (SynExpr.createLongIdent [ "Seq" ; "map" ])
-                    (dictionaryMapper (parseKeyString keyType) (parseNode None options valueType))
-            )
-            |> SynExpr.pipeThroughFunction (SynExpr.createIdent "readOnlyDict")
+            match JsonNodeWithNullability.Identify valueType with
+            | CannotBeNull ->
+                node
+                |> asObject propertyName
+                |> SynExpr.pipeThroughFunction (
+                    SynExpr.applyFunction
+                        (SynExpr.createLongIdent [ "Seq" ; "map" ])
+                        (dictionaryMapper
+                            propertyName
+                            false
+                            (parseKeyString keyType)
+                            valueType
+                            (parseNonNullableNode None options valueType))
+                )
+                |> SynExpr.pipeThroughFunction (SynExpr.createIdent "readOnlyDict")
+            | Nullable ->
+                node
+                |> asObject propertyName
+                |> SynExpr.pipeThroughFunction (
+                    SynExpr.applyFunction
+                        (SynExpr.createLongIdent [ "Seq" ; "map" ])
+                        (dictionaryMapper
+                            propertyName
+                            true
+                            (parseKeyString keyType)
+                            valueType
+                            (parseNullableNode None options valueType))
+                )
+                |> SynExpr.pipeThroughFunction (SynExpr.createIdent "readOnlyDict")
         | MapType (keyType, valueType) ->
-            node
-            |> asObject propertyName
-            |> SynExpr.pipeThroughFunction (
-                SynExpr.applyFunction
-                    (SynExpr.createLongIdent [ "Seq" ; "map" ])
-                    (dictionaryMapper (parseKeyString keyType) (parseNode None options valueType))
-            )
-            |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "Map" ; "ofSeq" ])
+            match JsonNodeWithNullability.Identify valueType with
+            | CannotBeNull ->
+                node
+                |> asObject propertyName
+                |> SynExpr.pipeThroughFunction (
+                    SynExpr.applyFunction
+                        (SynExpr.createLongIdent [ "Seq" ; "map" ])
+                        (dictionaryMapper
+                            propertyName
+                            false
+                            (parseKeyString keyType)
+                            valueType
+                            (parseNonNullableNode None options valueType))
+                )
+                |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "Map" ; "ofSeq" ])
+            | Nullable ->
+                node
+                |> asObject propertyName
+                |> SynExpr.pipeThroughFunction (
+                    SynExpr.applyFunction
+                        (SynExpr.createLongIdent [ "Seq" ; "map" ])
+                        (dictionaryMapper
+                            propertyName
+                            true
+                            (parseKeyString keyType)
+                            valueType
+                            (parseNullableNode None options valueType))
+                )
+                |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "Map" ; "ofSeq" ])
         | BigInt ->
             node
             |> SynExpr.callMethod "ToJsonString"
@@ -282,7 +457,7 @@ module internal JsonParseGenerator =
             |> SynExpr.pipeThroughFunction (Measure.getLanguagePrimitivesMeasure primType)
         | JsonNode -> node
         | UnitType -> SynExpr.CreateConst ()
-        | _ ->
+        | fieldType ->
             // Let's just hope that we've also got our own type annotation!
             let typeName =
                 match fieldType with
@@ -291,14 +466,45 @@ module internal JsonParseGenerator =
 
             match propertyName with
             | None -> node
-            | Some propertyName -> assertNotNull propertyName node
+            | Some propertyName -> assertPropertyExists propertyName node
             |> typeJsonParse typeName
 
     /// propertyName is probably a string literal, but it could be a [<Literal>] variable
     /// The result of this function is the body of a let-binding (not including the LHS of that let-binding).
     let createParseRhs (options : JsonParseOption) (propertyName : SynExpr) (fieldType : SynType) : SynExpr =
-        let objectToParse = SynExpr.createIdent "node" |> SynExpr.index propertyName
-        parseNode (Some propertyName) options fieldType objectToParse
+        match JsonNodeWithNullability.Identify fieldType with
+        | Nullable ->
+            let objectToParse =
+                SynExpr.createIdent "node"
+                |> SynExpr.index propertyName
+                |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "Option" ; "ofObj" ])
+
+            parseNullableNode (Some propertyName) options fieldType objectToParse
+        | CannotBeNull ->
+            [
+                SynMatchClause.create
+                    (SynPat.named "None")
+                    (SynExpr.applyFunction
+                        (SynExpr.createIdent "raise")
+                        (SynExpr.paren (
+                            SynExpr.applyFunction
+                                (SynExpr.createLongIdent
+                                    [ "System" ; "Collections" ; "Generic" ; "KeyNotFoundException" ])
+                                (SynExpr.applyFunction
+                                    (SynExpr.createIdent "sprintf")
+                                    (SynExpr.CreateConst "Required key '%s' not found on JSON object")
+                                 |> SynExpr.applyTo (SynExpr.paren propertyName)
+                                 |> SynExpr.paren)
+                        )))
+                SynMatchClause.create
+                    (SynPat.nameWithArgs "Some" [ SynPat.named "node" ])
+                    (parseNonNullableNode None options fieldType (SynExpr.createIdent "node"))
+            ]
+            |> SynExpr.createMatch (
+                SynExpr.createIdent "node"
+                |> SynExpr.index propertyName
+                |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "Option" ; "ofObj" ])
+            )
 
     let isJsonNumberHandling (literal : LongIdent) : bool =
         match List.rev literal |> List.map (fun ident -> ident.idText) with
@@ -480,7 +686,7 @@ module internal JsonParseGenerator =
         let finalConstruction =
             fields
             |> List.mapi (fun i fieldData -> SynLongIdent.createI fieldData.Ident, SynExpr.createIdent $"arg_%i{i}")
-            |> AstHelper.instantiateRecord
+            |> SynExpr.createRecord None
 
         (finalConstruction, assignments)
         ||> List.fold (fun final assignment -> SynExpr.createLet [ assignment ] final)
@@ -505,7 +711,8 @@ module internal JsonParseGenerator =
                     |> SynExpr.createLet
                         [
                             SynExpr.index (SynExpr.CreateConst "data") (SynExpr.createIdent "node")
-                            |> assertNotNull (SynExpr.CreateConst "data")
+                            |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "Option" ; "ofObj" ])
+                            |> assertPropertyExists (SynExpr.CreateConst "data")
                             |> SynBinding.basic [ Ident.create "node" ] []
                         ]
 
@@ -553,7 +760,8 @@ module internal JsonParseGenerator =
 
                 SynExpr.createIdent "node"
                 |> SynExpr.index property
-                |> assertNotNull property
+                |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "Option" ; "ofObj" ])
+                |> assertPropertyExists property
                 |> SynExpr.pipeThroughFunction (
                     SynExpr.createLambda "v" (SynExpr.callGenericMethod' "GetValue" "string" (SynExpr.createIdent "v"))
                 )

WoofWare.Myriad.Plugins/JsonSerializeGenerator.fs

@@ -10,24 +10,100 @@ type internal JsonSerializeOutputSpec =
         ExtensionMethods : bool
     }
 
+/// https://github.com/Smaug123/WoofWare.Myriad/issues/364
+/// The insane design of System.Text.Json is finally causing us to
+/// do vast amounts of coding rather than merely being very annoying.
+type internal JsonNodeWithNullability =
+    | CannotBeNull
+    | Nullable
+
+    static member Identify (ty : SynType) : JsonNodeWithNullability =
+        match ty with
+        | OptionType _
+        | NullableType _ -> JsonNodeWithNullability.Nullable
+        | _ -> JsonNodeWithNullability.CannotBeNull
+
 [<RequireQualifiedAccess>]
 module internal JsonSerializeGenerator =
     open Fantomas.FCS.Text.Range
 
 
     // The absolutely galaxy-brained implementation of JsonValue has `JsonValue.Parse "null"`
-    // identically equal to null. We have to work around this later, but we might as well just
-    // be efficient here and whip up the null directly.
-    let private jsonNull () =
-        SynExpr.createNull ()
-        |> SynExpr.upcast' (SynType.createLongIdent' [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonNode" ])
+    // identically equal to null, so it's hard to use that type. We use `None` instead to represent
+    // the JSON null value.
+    let private jsonNull () = SynExpr.createIdent "None"
+
+    let assertNotNull (boundIdent : Ident) (message : SynExpr) (body : SynExpr) : SynExpr =
+        let raiseExpr =
+            message
+            |> SynExpr.applyFunction (SynExpr.createLongIdent [ "System" ; "ArgumentNullException" ])
+            |> SynExpr.paren
+            |> SynExpr.applyFunction (SynExpr.createIdent "raise")
+
+        [
+            SynMatchClause.create SynPat.createNull raiseExpr
+            SynMatchClause.create (SynPat.namedI boundIdent) body
+        ]
+        |> SynExpr.createMatch (SynExpr.createIdent' boundIdent)
+        |> SynExpr.paren
+
+    /// The output of this will be an *optional* JsonNode.
+    let rec serializeNodeNullable (fieldType : SynType) : SynExpr * bool =
+        match fieldType with
+        | NullableType ty ->
+            // fun field -> if field.HasValue then {serializeNode ty} field.Value else JsonValue.Create null
+            match JsonNodeWithNullability.Identify ty with
+            | JsonNodeWithNullability.Nullable ->
+                failwith
+                    $"We don't support nested nullable types, because we can't tell the difference between None and Some None: %s{SynType.toHumanReadableString ty}"
+            | JsonNodeWithNullability.CannotBeNull ->
+
+            let inner, innerIsJsonNode = serializeNodeNonNullable ty
+
+            SynExpr.applyFunction inner (SynExpr.createLongIdent [ "field" ; "Value" ])
+            |> SynExpr.upcast' (SynType.createLongIdent' [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonNode" ])
+            |> SynExpr.pipeThroughFunction (SynExpr.createIdent "Some")
+            |> SynExpr.ifThenElse (SynExpr.createLongIdent [ "field" ; "HasValue" ]) (jsonNull ())
+            |> SynExpr.createLambda "field"
+            |> fun e -> e, innerIsJsonNode
+        | OptionType ty ->
+            // fun field -> match field with | None -> None | Some v -> {serializeNode ty} field |> Some
+            match JsonNodeWithNullability.Identify ty with
+            | JsonNodeWithNullability.Nullable ->
+                failwith
+                    $"We don't support nested nullable types, because we can't tell the difference between None and Some None: %s{SynType.toHumanReadableString ty}"
+            | JsonNodeWithNullability.CannotBeNull ->
+
+            let noneClause = jsonNull () |> SynMatchClause.create (SynPat.named "None")
+
+            let someClause =
+                let inner, innerIsJsonNode = serializeNodeNonNullable ty
+                let target = SynExpr.pipeThroughFunction inner (SynExpr.createIdent "field")
+
+                if innerIsJsonNode then
+                    target
+                else
+                    target
+                    |> SynExpr.paren
+                    |> SynExpr.upcast' (SynType.createLongIdent' [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonNode" ])
+                |> SynExpr.pipeThroughFunction (SynExpr.createIdent "Some")
+                |> SynMatchClause.create (SynPat.nameWithArgs "Some" [ SynPat.named "field" ])
+
+            [ noneClause ; someClause ]
+            |> SynExpr.createMatch (SynExpr.createIdent "field")
+            |> SynExpr.createLambda "field"
+            |> fun e -> e, true
+        | _ -> failwith $"Did not recognise type %s{SynType.toHumanReadableString fieldType} as nullable"
 
     /// Given `input.Ident`, for example, choose how to add it to the ambient `node`.
     /// The result is a line like `(fun ident -> InnerType.toJsonNode ident)` or `(fun ident -> JsonValue.Create ident)`.
     /// Returns also a bool which is true if the resulting SynExpr represents something of type JsonNode.
-    let rec serializeNode (fieldType : SynType) : SynExpr * bool =
+    and serializeNodeNonNullable (fieldType : SynType) : SynExpr * bool =
         // TODO: serialization format for DateTime etc
         match fieldType with
+        | OptionType _
+        | NullableType _ ->
+            failwith $"Tried to treat the type %s{SynType.toHumanReadableString fieldType} as non-nullable"
         | DateOnly
         | DateTime
         | NumberType _
@@ -36,8 +112,21 @@ module internal JsonSerializeGenerator =
         | Guid
         | Uri ->
             // JsonValue.Create<type>
-            SynExpr.createLongIdent [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonValue" ; "Create" ]
-            |> SynExpr.typeApp [ fieldType ]
+            (SynExpr.createIdent "field")
+            |> assertNotNull
+                (Ident.create "field")
+                (SynExpr.CreateConst
+                    $"Expected type %s{SynType.toHumanReadableString fieldType} to be non-null, but received a null value when serialising")
+            |> SynExpr.createLet
+                [
+                    SynBinding.basic
+                        [ Ident.create "field" ]
+                        []
+                        (SynExpr.createLongIdent [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonValue" ; "Create" ]
+                         |> SynExpr.typeApp [ fieldType ]
+                         |> SynExpr.applyTo (SynExpr.createIdent "field"))
+                ]
+            |> SynExpr.createLambda "field"
             |> fun e -> e, false
         | DateTimeOffset ->
             // fun field -> field.ToString("o") |> JsonValue.Create<string>
@@ -50,41 +139,17 @@ module internal JsonSerializeGenerator =
             |> SynExpr.pipeThroughFunction create
             |> SynExpr.createLambda "field"
             |> fun e -> e, false
-        | NullableType ty ->
-            // fun field -> if field.HasValue then {serializeNode ty} field.Value else JsonValue.Create null
-            let inner, innerIsJsonNode = serializeNode ty
-
-            SynExpr.applyFunction inner (SynExpr.createLongIdent [ "field" ; "Value" ])
-            |> SynExpr.upcast' (SynType.createLongIdent' [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonNode" ])
-            |> SynExpr.ifThenElse (SynExpr.createLongIdent [ "field" ; "HasValue" ]) (jsonNull ())
-            |> SynExpr.createLambda "field"
-            |> fun e -> e, innerIsJsonNode
-        | OptionType ty ->
-            // fun field -> match field with | None -> JsonValue.Create null | Some v -> {serializeNode ty} field
-            let noneClause = jsonNull () |> SynMatchClause.create (SynPat.named "None")
-
-            let someClause =
-                let inner, innerIsJsonNode = serializeNode ty
-                let target = SynExpr.applyFunction inner (SynExpr.createIdent "field")
-
-                if innerIsJsonNode then
-                    target
-                else
-                    target
-                    |> SynExpr.paren
-                    |> SynExpr.upcast' (SynType.createLongIdent' [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonNode" ])
-                |> SynMatchClause.create (SynPat.nameWithArgs "Some" [ SynPat.named "field" ])
-
-            [ noneClause ; someClause ]
-            |> SynExpr.createMatch (SynExpr.createIdent "field")
-            |> SynExpr.createLambda "field"
-            |> fun e -> e, true
         | ArrayType ty
         | ListType ty ->
             // fun field ->
             //     let arr = JsonArray ()
             //     for mem in field do arr.Add ({serializeNode} mem)
             //     arr
+            let isNullableChild =
+                match JsonNodeWithNullability.Identify ty with
+                | CannotBeNull -> false
+                | Nullable -> true
+
             [
                 SynExpr.ForEach (
                     DebugPointAtFor.Yes range0,
@@ -95,7 +160,17 @@ module internal JsonSerializeGenerator =
                     SynExpr.createIdent "field",
                     SynExpr.applyFunction
                         (SynExpr.createLongIdent [ "arr" ; "Add" ])
-                        (SynExpr.paren (SynExpr.applyFunction (fst (serializeNode ty)) (SynExpr.createIdent "mem"))),
+                        (SynExpr.paren (
+                            SynExpr.applyFunction
+                                (fst (
+                                    (if isNullableChild then
+                                         serializeNodeNullable
+                                     else
+                                         serializeNodeNonNullable)
+                                        ty
+                                ))
+                                (SynExpr.createIdent "mem")
+                        )),
                     range0
                 )
                 SynExpr.createIdent "arr"
@@ -109,15 +184,28 @@ module internal JsonSerializeGenerator =
                 ]
             |> SynExpr.createLambda "field"
             |> fun e -> e, false
-        | IDictionaryType (_keyType, valueType)
-        | DictionaryType (_keyType, valueType)
-        | IReadOnlyDictionaryType (_keyType, valueType)
-        | MapType (_keyType, valueType) ->
+        | IDictionaryType (keyType, valueType)
+        | DictionaryType (keyType, valueType)
+        | IReadOnlyDictionaryType (keyType, valueType)
+        | MapType (keyType, valueType) ->
             // fun field ->
             //    let ret = JsonObject ()
             //    for (KeyValue(key, value)) in field do
             //        ret.Add (key.ToString (), {serializeNode} value)
             //    ret
+            let isNullableValueField =
+                match JsonNodeWithNullability.Identify valueType with
+                | CannotBeNull -> false
+                | Nullable -> true
+
+            // TODO: this is a bit dubious, because user-defined types will
+            // by default have non-null ToString
+            let keyTypeHasNonNullToString =
+                match keyType with
+                | String
+                | Uri -> true
+                | _ -> false
+
             [
                 SynExpr.ForEach (
                     DebugPointAtFor.Yes range0,
@@ -130,10 +218,33 @@ module internal JsonSerializeGenerator =
                         (SynExpr.createLongIdent [ "ret" ; "Add" ])
                         (SynExpr.tuple
                             [
-                                SynExpr.createLongIdent [ "key" ; "ToString" ]
-                                |> SynExpr.applyTo (SynExpr.CreateConst ())
-                                SynExpr.applyFunction (fst (serializeNode valueType)) (SynExpr.createIdent "value")
-                            ]),
+                                SynExpr.createIdent "key"
+                                |> if keyTypeHasNonNullToString then
+                                       id
+                                   else
+                                       assertNotNull
+                                           (Ident.create "key")
+                                           (SynExpr.CreateConst
+                                               "A map key unexpectedly yielded null when we `ToString`'ed it. Map keys must yield non-null strings on `ToString`.")
+
+                                SynExpr.applyFunction
+                                    (fst (
+                                        (if isNullableValueField then
+                                             serializeNodeNullable
+                                         else
+                                             serializeNodeNonNullable)
+                                            valueType
+                                    ))
+                                    (SynExpr.createIdent "value")
+                            ])
+                    |> SynExpr.createLet
+                        [
+                            SynBinding.basic
+                                [ Ident.create "key" ]
+                                []
+                                (SynExpr.createLongIdent [ "key" ; "ToString" ]
+                                 |> SynExpr.applyTo (SynExpr.CreateConst ()))
+                        ],
                     range0
                 )
                 SynExpr.createIdent "ret"
@@ -166,13 +277,24 @@ module internal JsonSerializeGenerator =
     /// propertyName is probably a string literal, but it could be a [<Literal>] variable
     /// `node.Add ({propertyName}, {toJsonNode})`
     let createSerializeRhsRecord (propertyName : SynExpr) (fieldId : Ident) (fieldType : SynType) : SynExpr =
-        [
-            propertyName
-            SynExpr.pipeThroughFunction
-                (fst (serializeNode fieldType))
-                (SynExpr.createLongIdent' [ Ident.create "input" ; fieldId ])
-            |> SynExpr.paren
-        ]
+        let isNullableField =
+            match JsonNodeWithNullability.Identify fieldType with
+            | CannotBeNull -> false
+            | Nullable -> true
+
+        let serialised =
+            if isNullableField then
+                let value =
+                    serializeNodeNullable fieldType
+                    |> fst
+                    |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "Option" ; "toObj" ])
+
+                SynExpr.pipeThroughFunction value (SynExpr.createLongIdent' [ Ident.create "input" ; fieldId ])
+            else
+                let value = serializeNodeNonNullable fieldType |> fst
+                SynExpr.pipeThroughFunction value (SynExpr.createLongIdent' [ Ident.create "input" ; fieldId ])
+
+        [ propertyName ; SynExpr.paren serialised ]
         |> SynExpr.tuple
         |> SynExpr.applyFunction (SynExpr.createLongIdent [ "node" ; "Add" ])
 
@@ -278,7 +400,10 @@ module internal JsonSerializeGenerator =
                     | DictionaryType (String, v) -> v
                     | _ -> failwith "Expected JsonExtensionData to be a Dictionary<string, something>"
 
-                let serialise = fst (serializeNode valType)
+                let serialise =
+                    match JsonNodeWithNullability.Identify valType with
+                    | CannotBeNull -> fst (serializeNodeNonNullable valType)
+                    | Nullable -> fst (serializeNodeNullable valType)
 
                 SynExpr.createIdent "node"
                 |> SynExpr.callMethodArg
@@ -343,7 +468,15 @@ module internal JsonSerializeGenerator =
                     let propertyName = getPropertyName (Option.get fieldData.Ident) fieldData.Attrs
 
                     let node =
-                        SynExpr.applyFunction (fst (serializeNode fieldData.Type)) (SynExpr.createIdent caseName)
+                        match JsonNodeWithNullability.Identify fieldData.Type with
+                        | CannotBeNull ->
+                            SynExpr.applyFunction
+                                (fst (serializeNodeNonNullable fieldData.Type))
+                                (SynExpr.createIdent caseName)
+                        | Nullable ->
+                            SynExpr.applyFunction
+                                (fst (serializeNodeNullable fieldData.Type))
+                                (SynExpr.createIdent caseName)
 
                     [ propertyName ; node ]
                     |> SynExpr.tuple

WoofWare.Myriad.Plugins/RemoveOptionsGenerator.fs

@@ -97,7 +97,7 @@ module internal RemoveOptionsGenerator =
 
                 SynLongIdent.createI fieldData.Ident, body
             )
-            |> AstHelper.instantiateRecord
+            |> SynExpr.createRecord None
 
         SynBinding.basic
             [ functionName ]

WoofWare.Myriad.Plugins/Swagger.fs

@@ -198,7 +198,14 @@ and ObjectTypeDefinition =
                 |> Map.ofSeq
                 |> Some
 
-        let example = asObjOpt node "example"
+        let example =
+            match node.["example"] with
+            | null -> None
+            | :? JsonObject as o -> Some o
+            | _ ->
+                // Gitea returns a stringified and malformed JSON object here.
+                // Don't throw; just omit.
+                None
 
         let required = asArrOpt'<string> node "required"
 

WoofWare.Myriad.Plugins/SwaggerClientGenerator.fs

@@ -1,7 +1,6 @@
 namespace WoofWare.Myriad.Plugins
 
 open System.Collections.Generic
-open System.IO
 open System.Threading
 open Fantomas.FCS.Syntax
 open Fantomas.FCS.Xml
@@ -19,6 +18,7 @@ type internal SwaggerClientConfig =
 type internal Produces =
     // TODO: this will cope with decoding JSON, plain text, etc
     | Produces of string
+    | OctetStream
 
 type internal Endpoint =
     {
@@ -47,16 +47,8 @@ type internal Types =
 
 [<RequireQualifiedAccess>]
 module internal SwaggerClientGenerator =
-    let outputFile = FileInfo "/tmp/output.txt"
 
-    // do
-    //     use _ = File.Create outputFile.FullName
-    //     ()
-
-    let log (line : string) =
-        // use w = outputFile.AppendText ()
-        // w.WriteLine line
-        ()
+    let internal log (_ : string) = ()
 
     let renderType (types : Types) (defn : Definition) : SynType option =
         match types.ByDefinition.TryGetValue defn with
@@ -477,6 +469,15 @@ module internal SwaggerClientGenerator =
                             (SynLongIdent.createS' [ "RestEase" ; "Header" ])
                             // Gitea, at least, starts with a `/`, which `Uri` then takes to indicate an absolute path.
                             (SynExpr.tuple [ SynExpr.CreateConst "Content-Type" ; SynExpr.CreateConst contentType ])
+                    | Produces.OctetStream ->
+                        SynAttribute.create
+                            (SynLongIdent.createS' [ "RestEase" ; "Header" ])
+                            // Gitea, at least, starts with a `/`, which `Uri` then takes to indicate an absolute path.
+                            (SynExpr.tuple
+                                [
+                                    SynExpr.CreateConst "Content-Type"
+                                    SynExpr.CreateConst "application/octet-stream"
+                                ])
                 ]
 
             returnType
@@ -512,6 +513,7 @@ module internal SwaggerClientGenerator =
         |> List.singleton
 
 open Myriad.Core
+open System.IO
 
 /// Myriad generator that stamps out an interface and class to access a Swagger-specified API.
 [<MyriadGenerator("swagger-client")>]
@@ -622,10 +624,11 @@ type SwaggerClientGenerator () =
 
                         let produces =
                             match endpoint.Produces with
-                            | None -> Produces "json"
+                            | None -> Produces.Produces "json"
                             | Some [] -> failwith $"API specified empty Produces: %s{path} (%O{method})"
-                            | Some [ MimeType "application/json" ] -> Produces "json"
-                            | Some [ MimeType (StartsWith "text/" t) ] -> Produces t
+                            | Some [ MimeType "application/octet-stream" ] -> Produces.OctetStream
+                            | Some [ MimeType "application/json" ] -> Produces.Produces "json"
+                            | Some [ MimeType (StartsWith "text/" t) ] -> Produces.Produces t
                             | Some [ MimeType s ] ->
                                 failwithf
                                     $"we don't support non-JSON Produces right now, got: %s{s} (%s{path} %O{method})"

WoofWare.Myriad.Plugins/WoofWare.Myriad.Plugins.fsproj

@@ -22,7 +22,7 @@
   <ItemGroup>
     <PackageReference Include="Myriad.Core" Version="0.8.3" />
     <PackageReference Include="TypeEquality" Version="0.3.0" />
-    <PackageReference Include="WoofWare.Whippet.Fantomas" Version="0.3.1" />
+    <PackageReference Include="WoofWare.Whippet.Fantomas" Version="0.6.2" />
     <!-- the lowest version allowed by Myriad.Core -->
     <PackageReference Update="FSharp.Core" Version="6.0.1" PrivateAssets="all"/>
   </ItemGroup>

WoofWare.Myriad.Plugins/version.json

@@ -1,5 +1,5 @@
 {
-  "version": "4.0",
+  "version": "7.0",
   "publicReleaseRefSpec": [
     "^refs/heads/main$"
   ],
@@ -11,4 +11,4 @@
     ":/README.md",
     ":/Directory.Build.props"
   ]
-}
+}

analyzers/analyzers.fsproj

@@ -10,7 +10,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageDownload Include="G-Research.FSharp.Analyzers" Version="[0.12.0]" />
+    <PackageDownload Include="G-Research.FSharp.Analyzers" Version="[0.14.0]" />
   </ItemGroup>
 
 </Project>

flake.lock

@@ -20,11 +20,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1739019272,
-        "narHash": "sha256-7Fu7oazPoYCbDzb9k8D/DdbKrC3aU1zlnc39Y8jy/s8=",
+        "lastModified": 1744868846,
+        "narHash": "sha256-5RJTdUHDmj12Qsv7XOhuospjAjATNiTMElplWnJE9Hs=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "fa35a3c8e17a3de613240fea68f876e5b4896aec",
+        "rev": "ebe4301cbd8f81c4f8d3244b3632338bbeb6d49c",
         "type": "github"
       },
       "original": {

nix/deps.json

@@ -1,13 +1,13 @@
 [
   {
     "pname": "ApiSurface",
-    "version": "4.1.16",
-    "hash": "sha256-3F+dY2nZMFukUjIGrvB/h3ZsZYdLJ9jvQKRxX33qk2E="
+    "version": "4.1.20",
+    "hash": "sha256-koWgO9FC9ax+Ij56ug8kxeyknl0yhLqnNLOUdxtqqo4="
   },
   {
     "pname": "fantomas",
-    "version": "7.0.0",
-    "hash": "sha256-v4bXmvjZOYxl5RSIHuqVfDzBQdRz5SrmzZtD6SeEYTY="
+    "version": "7.0.1",
+    "hash": "sha256-2aGD6Kjh83gmssRqqZ/Uihi7VbNqNUelX4otIfCuhTI="
   },
   {
     "pname": "Fantomas.Core",
@@ -21,29 +21,19 @@
   },
   {
     "pname": "FsCheck",
-    "version": "3.1.0",
-    "hash": "sha256-u0Ha94EjClJ8evNSHu8d6+Dx9qYM3kV3sl1PEq9gF8s="
+    "version": "3.2.0",
+    "hash": "sha256-ksZ4vLgWwyQOzFuK2BczdtDtWWYmedG7UBAg4pYuI8g="
   },
   {
     "pname": "fsharp-analyzers",
-    "version": "0.28.0",
-    "hash": "sha256-BqGk9MzHHA3oRPNfWuANcM1YELsdhzWI+kLF4mUDUx8="
+    "version": "0.30.0",
+    "hash": "sha256-7oaSwpHAU1opzpz4szLU/gDaJC/ww9eiFkPu0nr4Mj4="
   },
   {
     "pname": "FSharp.Core",
     "version": "4.3.4",
     "hash": "sha256-styyo+6mJy+yxE0NZG/b1hxkAjPOnJfMgd9zWzCJ5uk="
   },
-  {
-    "pname": "FSharp.Core",
-    "version": "4.5.0",
-    "hash": "sha256-7+B+8rsm/dMKvNBty8z5qB+kOxMwUzExy0F04xM88sk="
-  },
-  {
-    "pname": "FSharp.Core",
-    "version": "5.0.2",
-    "hash": "sha256-YOoosLEiszPsOOaNAkWhFGU04JJKDOFVoA/ggrZMN10="
-  },
   {
     "pname": "FSharp.Core",
     "version": "6.0.1",
@@ -51,13 +41,18 @@
   },
   {
     "pname": "FSharp.Core",
-    "version": "9.0.101",
-    "hash": "sha256-bR4PHanvKrzD43qFQxmOmmhhpz+ZmKZMPlgGnlRNcp4="
+    "version": "9.0.202",
+    "hash": "sha256-64Gub0qemmCoMa1tDus6TeTuB1+5sHfE6KD2j4o84mA="
   },
   {
     "pname": "FsUnit",
-    "version": "6.0.1",
-    "hash": "sha256-vka/aAgWhDCl5tu+kgO7GtSaHOOvlSaWxG+tExwGXpI="
+    "version": "7.0.1",
+    "hash": "sha256-K85CIdxMeFSHEKZk6heIXp/oFjWAn7dBILKrw49pJUY="
+  },
+  {
+    "pname": "Microsoft.ApplicationInsights",
+    "version": "2.22.0",
+    "hash": "sha256-mUQ63atpT00r49ca50uZu2YCiLg3yd6r3HzTryqcuEA="
   },
   {
     "pname": "Microsoft.AspNetCore.App.Ref",
@@ -86,13 +81,13 @@
   },
   {
     "pname": "Microsoft.CodeCoverage",
-    "version": "17.12.0",
-    "hash": "sha256-lGjifppD0OBMBp28pjUfPipaeXg739n8cPhtHWoo5RE="
+    "version": "17.13.0",
+    "hash": "sha256-GKrIxeyQo5Az1mztfQgea1kGtJwonnNOrXK/0ULfu8o="
   },
   {
     "pname": "Microsoft.NET.Test.Sdk",
-    "version": "17.12.0",
-    "hash": "sha256-DKFEbhh2wPzahNeHdEoFig8tZh/LEVrFc5+zpT43Btg="
+    "version": "17.13.0",
+    "hash": "sha256-sc2wvyV8cGm1FrNP2GGHEI584RCvRPu15erYCsgw5QY="
   },
   {
     "pname": "Microsoft.NETCore.App.Host.linux-arm64",
@@ -164,15 +159,45 @@
     "version": "1.1.3",
     "hash": "sha256-WLsf1NuUfRWyr7C7Rl9jiua9jximnVvzy6nk2D2bVRc="
   },
+  {
+    "pname": "Microsoft.Testing.Extensions.Telemetry",
+    "version": "1.5.3",
+    "hash": "sha256-bIXwPSa3jkr2b6xINOqMUs6/uj/r4oVFM7xq3uVIZDU="
+  },
+  {
+    "pname": "Microsoft.Testing.Extensions.TrxReport.Abstractions",
+    "version": "1.5.3",
+    "hash": "sha256-IfMRfcyaIKEMRtx326ICKtinDBEfGw/Sv8ZHawJ96Yc="
+  },
+  {
+    "pname": "Microsoft.Testing.Extensions.VSTestBridge",
+    "version": "1.5.3",
+    "hash": "sha256-XpM/yFjhLSsuzyDV+xKubs4V1zVVYiV05E0+N4S1h0g="
+  },
+  {
+    "pname": "Microsoft.Testing.Platform",
+    "version": "1.5.3",
+    "hash": "sha256-y61Iih6w5D79dmrj2V675mcaeIiHoj1HSa1FRit2BLM="
+  },
+  {
+    "pname": "Microsoft.Testing.Platform.MSBuild",
+    "version": "1.5.3",
+    "hash": "sha256-YspvjE5Jfi587TAfsvfDVJXNrFOkx1B3y1CKV6m7YLY="
+  },
   {
     "pname": "Microsoft.TestPlatform.ObjectModel",
     "version": "17.12.0",
     "hash": "sha256-3XBHBSuCxggAIlHXmKNQNlPqMqwFlM952Av6RrLw1/w="
   },
+  {
+    "pname": "Microsoft.TestPlatform.ObjectModel",
+    "version": "17.13.0",
+    "hash": "sha256-6S0fjfj8vA+h6dJVNwLi6oZhYDO/I/6hBZaq2VTW+Uk="
+  },
   {
     "pname": "Microsoft.TestPlatform.TestHost",
-    "version": "17.12.0",
-    "hash": "sha256-rf8Sh0fQq44Sneuvs64unkkIHg8kOjDGWE35j9iLx5I="
+    "version": "17.13.0",
+    "hash": "sha256-L/CJzou7dhmShUgXq3aXL3CaLTJll17Q+JY2DBdUUpo="
   },
   {
     "pname": "Myriad.Core",
@@ -186,8 +211,8 @@
   },
   {
     "pname": "Nerdbank.GitVersioning",
-    "version": "3.7.115",
-    "hash": "sha256-sqn+i7vvBgBUtm7j82mH+SpApgI2hsmL5DYfLm1Z7gw="
+    "version": "3.8.38-alpha",
+    "hash": "sha256-gPMrVbjOZxXoofczF/pn6eVkLhjVSJIyQrLO2oljrDc="
   },
   {
     "pname": "NETStandard.Library",
@@ -206,38 +231,33 @@
   },
   {
     "pname": "NuGet.Common",
-    "version": "6.12.1",
-    "hash": "sha256-k6JAFqHFinTakwNuW666aXYPhR7TpI/rb+KbHm1S2TM="
+    "version": "6.13.2",
+    "hash": "sha256-ASLa/Jigg5Eop0ZrXPl98RW2rxnJRC7pbbxhuV74hFw="
   },
   {
     "pname": "NuGet.Configuration",
-    "version": "6.12.1",
-    "hash": "sha256-e/4lvyl7o7g4aWTAtr9S2yiGgk7V0E9p6DXpsy7GgVw="
+    "version": "6.13.2",
+    "hash": "sha256-z8VW1YdRDanyyRTDYRvRkSv/XPR3c/hMM1y8cNNjx0Y="
   },
   {
     "pname": "NuGet.Frameworks",
-    "version": "6.12.1",
-    "hash": "sha256-GGpkbas+PNLx35vvr3nyAVz5lY/aeoMx6qjmT368Lpg="
+    "version": "6.13.2",
+    "hash": "sha256-caDyc+WgYOo43AUTjtbP0MyvYDb6JweEKDdIul61Cac="
   },
   {
     "pname": "NuGet.Packaging",
-    "version": "6.12.1",
-    "hash": "sha256-3h8Nmjpt383+dCg9GJ1BJ26UirwEQsWCPcTiT0+wGeI="
+    "version": "6.13.2",
+    "hash": "sha256-lhO+SFwIYZ4aPHxIGm5ubkkE2a5Ve2xgtroRbNh7hpw="
   },
   {
     "pname": "NuGet.Protocol",
-    "version": "6.12.1",
-    "hash": "sha256-l+CHnAcit6Y9OjBxereRP5JzOuWbuZZQYkFOKsUkdQ8="
+    "version": "6.13.2",
+    "hash": "sha256-5lnAHHZjy7A4vgv65AeBAs64mSNpuoUjxW3HnrMpuzY="
   },
   {
     "pname": "NuGet.Versioning",
-    "version": "6.12.1",
-    "hash": "sha256-f/ejCuzCAwKs4N4Ec6yf2RovrhBT0nj0hRDP+03/Iy4="
-  },
-  {
-    "pname": "NUnit",
-    "version": "4.0.1",
-    "hash": "sha256-jd1CD5nHVXkpvBNpVDJcJyfTggCHLyDBySVSvtrA8Uk="
+    "version": "6.13.2",
+    "hash": "sha256-gmpyBpKnt+GHqgx/2uFKp+J2csbxEAy1E7WdVT117sw="
   },
   {
     "pname": "NUnit",
@@ -246,8 +266,8 @@
   },
   {
     "pname": "NUnit3TestAdapter",
-    "version": "4.6.0",
-    "hash": "sha256-9Yav2fYhC4w0OgsyUwU4/5rDy4FVDTpKnWHuwl/uKJQ="
+    "version": "5.0.0",
+    "hash": "sha256-7jZM4qAbIzne3AcdFfMbvbgogqpxvVe6q2S7Ls8xQy0="
   },
   {
     "pname": "RestEase",
@@ -269,6 +289,16 @@
     "version": "4.3.0",
     "hash": "sha256-c5tXWhE/fYbJVl9rXs0uHh3pTsg44YD1dJvyOA0WoMs="
   },
+  {
+    "pname": "System.Collections.Immutable",
+    "version": "8.0.0",
+    "hash": "sha256-F7OVjKNwpqbUh8lTidbqJWYi476nsq9n+6k0+QVRo3w="
+  },
+  {
+    "pname": "System.Diagnostics.DiagnosticSource",
+    "version": "5.0.0",
+    "hash": "sha256-6mW3N6FvcdNH/pB58pl+pFSCGWgyaP4hfVtC/SMWDV4="
+  },
   {
     "pname": "System.Diagnostics.DiagnosticSource",
     "version": "7.0.0",
@@ -339,15 +369,10 @@
     "version": "4.5.0",
     "hash": "sha256-BkUYNguz0e4NJp1kkW7aJBn3dyH9STwB5N8XqnlCsmY="
   },
-  {
-    "pname": "System.Text.Encodings.Web",
-    "version": "8.0.0",
-    "hash": "sha256-IUQkQkV9po1LC0QsqrilqwNzPvnc+4eVvq+hCvq8fvE="
-  },
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     "pname": "System.Text.Json",
-    "version": "8.0.4",
-    "hash": "sha256-g5oT7fbXxQ9Iah1nMCr4UUX/a2l+EVjJyTrw3FTbIaI="
+    "version": "8.0.5",
+    "hash": "sha256-yKxo54w5odWT6nPruUVsaX53oPRe+gKzGvLnnxtwP68="
   },
   {
     "pname": "TypeEquality",
@@ -356,7 +381,7 @@
   },
   {
     "pname": "WoofWare.Whippet.Fantomas",
-    "version": "0.3.1",
-    "hash": "sha256-i5oiqcrxzM90Ocuq5MIu2Ha5lV0aYu5nCvuwmFqp6NA="
+    "version": "0.6.2",
+    "hash": "sha256-nDT/W5eBwM/E+Z2oQ80maAGYrEyRJQXL1unxR9q6ztU="
   }
 ]