From f55a810608cd12bc14df077fa77b18c25f2c5bea Mon Sep 17 00:00:00 2001
From: Patrick Stevens <3138005+Smaug123@users.noreply.github.com>
Date: Wed, 14 Feb 2024 23:17:20 +0000
Subject: [PATCH] Allow cancellation token arg to have another name (#96)

---
 ConsumePlugin/GeneratedRestClient.fs          |  4 +-
 ConsumePlugin/RestApiExample.fs               |  2 +-
 README.md                                     |  5 +-
 .../HttpClientGenerator.fs                    | 49 +++++++++++--------
 WoofWare.Myriad.Plugins/SynExpr.fs            |  4 +-
 5 files changed, 35 insertions(+), 29 deletions(-)

diff --git a/ConsumePlugin/GeneratedRestClient.fs b/ConsumePlugin/GeneratedRestClient.fs
index 3c29f51..1033e74 100644
--- a/ConsumePlugin/GeneratedRestClient.fs
+++ b/ConsumePlugin/GeneratedRestClient.fs
@@ -1034,7 +1034,7 @@ module ApiWithBasePath =
     /// Create a REST client.
     let make (client : System.Net.Http.HttpClient) : IApiWithBasePath =
         { new IApiWithBasePath with
-            member _.GetPathParam (parameter : string, ct : CancellationToken option) =
+            member _.GetPathParam (parameter : string, cancellationToken : CancellationToken option) =
                 async {
                     let! ct = Async.CancellationToken
 
@@ -1067,7 +1067,7 @@ module ApiWithBasePath =
                     let! responseString = response.Content.ReadAsStringAsync ct |> Async.AwaitTask
                     return responseString
                 }
-                |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
+                |> (fun a -> Async.StartAsTask (a, ?cancellationToken = cancellationToken))
         }
 namespace PureGym
 
diff --git a/ConsumePlugin/RestApiExample.fs b/ConsumePlugin/RestApiExample.fs
index aa6f933..f373d2d 100644
--- a/ConsumePlugin/RestApiExample.fs
+++ b/ConsumePlugin/RestApiExample.fs
@@ -121,7 +121,7 @@ type internal IApiWithoutBaseAddress =
 [<BasePath "foo">]
 type IApiWithBasePath =
     [<Get "endpoint/{param}">]
-    abstract GetPathParam : [<Path "param">] parameter : string * ?ct : CancellationToken -> Task<string>
+    abstract GetPathParam : [<Path "param">] parameter : string * ?cancellationToken : CancellationToken -> Task<string>
 
 [<WoofWare.Myriad.Plugins.HttpClient>]
 [<BaseAddress "https://whatnot.com">]
diff --git a/README.md b/README.md
index 9430be2..636fcb1 100644
--- a/README.md
+++ b/README.md
@@ -322,10 +322,9 @@ The [Grug-brained developer](https://grugbrain.dev/) would prefer to do this wit
 But since F# does not let you partially update an interface definition, we instead stamp out a record,
 thereby allowing the programmer to use F#'s record-update syntax.
 
-### Limitations
+### Features
 
-* We make the resulting record type at most internal (never public), since this is intended only to be used in tests.
-  You will therefore need an `AssemblyInfo.fs` file [like the one in WoofWare.Myriad's own tests](./ConsumePlugin/AssemblyInfo.fs).
+* You may supply an `isInternal : bool` argument to the attribute. By default, we make the resulting record type at most internal (never public), since this is intended only to be used in tests; but you can instead make it public with `[<GenerateMock false>]`.
 
 # Detailed examples
 
diff --git a/WoofWare.Myriad.Plugins/HttpClientGenerator.fs b/WoofWare.Myriad.Plugins/HttpClientGenerator.fs
index bebaaa8..c6a8434 100644
--- a/WoofWare.Myriad.Plugins/HttpClientGenerator.fs
+++ b/WoofWare.Myriad.Plugins/HttpClientGenerator.fs
@@ -183,27 +183,34 @@ module internal HttpClientGenerator =
                 None
             )
 
+        let args =
+            info.Args
+            |> List.map (fun arg ->
+                let argName =
+                    match arg.Id with
+                    | None -> failwith "TODO: create an arg name"
+                    | Some id -> id
+
+                let argType =
+                    if arg.IsOptional then
+                        SynType.CreateApp (
+                            SynType.CreateLongIdent (SynLongIdent.CreateString "option"),
+                            [ arg.Type ],
+                            isPostfix = true
+                        )
+                    else
+                        arg.Type
+
+                argName, SynPat.CreateTyped (SynPat.CreateNamed argName, argType)
+            )
+
+        let cancellationTokenArg =
+            match List.tryLast args with
+            | None -> failwith $"expected an optional cancellation token as final arg in %s{info.Identifier.idText}"
+            | Some (arg, _) -> arg
+
         let argPats =
-            let args =
-                info.Args
-                |> List.map (fun arg ->
-                    let argName =
-                        match arg.Id with
-                        | None -> failwith "TODO: create an arg name"
-                        | Some id -> id
-
-                    let argType =
-                        if arg.IsOptional then
-                            SynType.CreateApp (
-                                SynType.CreateLongIdent (SynLongIdent.CreateString "option"),
-                                [ arg.Type ],
-                                isPostfix = true
-                            )
-                        else
-                            arg.Type
-
-                    SynPat.CreateTyped (SynPat.CreateNamed argName, argType)
-                )
+            let args = args |> List.map snd
 
             SynPat.Tuple (false, args, List.replicate (args.Length - 1) range0, range0)
             |> SynPat.CreateParen
@@ -677,7 +684,7 @@ module internal HttpClientGenerator =
                     yield jsonNode
             ]
             |> SynExpr.createCompExpr "async" returnExpr
-            |> SynExpr.startAsTask
+            |> SynExpr.startAsTask (SynLongIdent.CreateFromLongIdent [ cancellationTokenArg ])
 
         SynMemberDefn.Member (
             SynBinding.SynBinding (
diff --git a/WoofWare.Myriad.Plugins/SynExpr.fs b/WoofWare.Myriad.Plugins/SynExpr.fs
index d93a545..95805b5 100644
--- a/WoofWare.Myriad.Plugins/SynExpr.fs
+++ b/WoofWare.Myriad.Plugins/SynExpr.fs
@@ -180,7 +180,7 @@ module internal SynExpr =
         SynExpr.CreateApp (SynExpr.CreateIdent (Ident.Create "reraise"), SynExpr.CreateConst SynConst.Unit)
 
     /// {body} |> fun a -> Async.StartAsTask (a, ?cancellationToken=ct)
-    let startAsTask (body : SynExpr) =
+    let startAsTask (ct : SynLongIdent) (body : SynExpr) =
         let lambda =
             SynExpr.CreateApp (
                 SynExpr.CreateLongIdent (SynLongIdent.Create [ "Async" ; "StartAsTask" ]),
@@ -189,7 +189,7 @@ module internal SynExpr =
                         SynExpr.CreateLongIdent (SynLongIdent.CreateString "a")
                         equals
                             (SynExpr.LongIdent (true, SynLongIdent.CreateString "cancellationToken", None, range0))
-                            (SynExpr.CreateLongIdent (SynLongIdent.CreateString "ct"))
+                            (SynExpr.CreateLongIdent ct)
                     ]
             )
             |> createLambda "a"