Omit upcasts where possible (#178)

ConsumePlugin/GeneratedSerde.fs

@@ -236,6 +236,55 @@ module FirstDuJsonSerializeExtension =
                 node.Add ("data", dataNode)
 
             node :> _
+namespace ConsumePlugin
+
+open System
+open System.Collections.Generic
+open System.Text.Json.Serialization
+
+/// Module containing JSON serializing extension members for the HeaderAndValue type
+[<AutoOpen>]
+module HeaderAndValueJsonSerializeExtension =
+    /// Extension methods for JSON parsing
+    type HeaderAndValue with
+
+        /// Serialize to a JSON node
+        static member toJsonNode (input : HeaderAndValue) : System.Text.Json.Nodes.JsonNode =
+            let node = System.Text.Json.Nodes.JsonObject ()
+
+            do
+                node.Add ("header", (input.Header |> System.Text.Json.Nodes.JsonValue.Create<string>))
+                node.Add ("value", (input.Value |> System.Text.Json.Nodes.JsonValue.Create<string>))
+
+            node :> _
+namespace ConsumePlugin
+
+open System
+open System.Collections.Generic
+open System.Text.Json.Serialization
+
+/// Module containing JSON serializing extension members for the Foo type
+[<AutoOpen>]
+module FooJsonSerializeExtension =
+    /// Extension methods for JSON parsing
+    type Foo with
+
+        /// Serialize to a JSON node
+        static member toJsonNode (input : Foo) : System.Text.Json.Nodes.JsonNode =
+            let node = System.Text.Json.Nodes.JsonObject ()
+
+            do
+                node.Add (
+                    "message",
+                    (input.Message
+                     |> (fun field ->
+                         match field with
+                         | None -> null :> System.Text.Json.Nodes.JsonNode
+                         | Some field -> HeaderAndValue.toJsonNode field
+                     ))
+                )
+
+            node :> _
 
 namespace ConsumePlugin
 
@@ -717,3 +766,41 @@ module FirstDuJsonParseExtension =
                         .GetValue<System.Int32> ()
                 )
             | v -> failwith ("Unrecognised 'type' field value: " + v)
+namespace ConsumePlugin
+
+/// Module containing JSON parsing extension members for the HeaderAndValue type
+[<AutoOpen>]
+module HeaderAndValueJsonParseExtension =
+    /// Extension methods for JSON parsing
+    type HeaderAndValue with
+
+        /// Parse from a JSON node.
+        static member jsonParse (node : System.Text.Json.Nodes.JsonNode) : HeaderAndValue =
+            let arg_1 =
+                (match node.["value"] with
+                 | null ->
+                     raise (
+                         System.Collections.Generic.KeyNotFoundException (
+                             sprintf "Required key '%s' not found on JSON object" ("value")
+                         )
+                     )
+                 | v -> v)
+                    .AsValue()
+                    .GetValue<System.String> ()
+
+            let arg_0 =
+                (match node.["header"] with
+                 | null ->
+                     raise (
+                         System.Collections.Generic.KeyNotFoundException (
+                             sprintf "Required key '%s' not found on JSON object" ("header")
+                         )
+                     )
+                 | v -> v)
+                    .AsValue()
+                    .GetValue<System.String> ()
+
+            {
+                Header = arg_0
+                Value = arg_1
+            }

ConsumePlugin/SerializationAndDeserialization.fs

@@ -57,3 +57,17 @@ type FirstDu =
     | EmptyCase
     | Case1 of data : string
     | Case2 of record : JsonRecordTypeWithBoth * i : int
+
+[<WoofWare.Myriad.Plugins.JsonParse true>]
+[<WoofWare.Myriad.Plugins.JsonSerialize true>]
+type HeaderAndValue =
+    {
+        Header : string
+        Value : string
+    }
+
+[<WoofWare.Myriad.Plugins.JsonSerialize true>]
+type Foo =
+    {
+        Message : HeaderAndValue option
+    }

WoofWare.Myriad.Plugins/HttpClientGenerator.fs

@@ -449,7 +449,7 @@ module internal HttpClientGenerator =
                             SynExpr.createNew
                                 (SynType.createLongIdent' [ "System" ; "Net" ; "Http" ; "StringContent" ])
                                 (SynExpr.createIdent' bodyParamName
-                                 |> SynExpr.pipeThroughFunction (JsonSerializeGenerator.serializeNode ty)
+                                 |> SynExpr.pipeThroughFunction (fst (JsonSerializeGenerator.serializeNode ty))
                                  |> SynExpr.pipeThroughFunction (
                                      SynExpr.createLambda
                                          "node"

WoofWare.Myriad.Plugins/JsonSerializeGenerator.fs

@@ -23,7 +23,8 @@ module internal JsonSerializeGenerator =
 
     /// 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)`.
-    let rec serializeNode (fieldType : SynType) : SynExpr =
+    /// Returns also a bool which is true if the resulting SynExpr represents something of type JsonNode.
+    let rec serializeNode (fieldType : SynType) : SynExpr * bool =
         // TODO: serialization format for DateTime etc
         match fieldType with
         | DateOnly
@@ -36,20 +37,30 @@ module internal JsonSerializeGenerator =
             // JsonValue.Create<type>
             SynExpr.createLongIdent [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonValue" ; "Create" ]
             |> SynExpr.typeApp [ fieldType ]
+            |> fun e -> e, false
         | NullableType ty ->
             // fun field -> if field.HasValue then {serializeNode ty} field.Value else JsonValue.Create null
-            SynExpr.applyFunction (serializeNode ty) (SynExpr.createLongIdent [ "field" ; "Value" ])
+            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 =
-                SynExpr.applyFunction (serializeNode ty) (SynExpr.createIdent "field")
+                let inner, innerIsJsonNode = serializeNode ty
-                |> SynExpr.paren
+                let target = SynExpr.applyFunction inner (SynExpr.createIdent "field")
-                |> SynExpr.upcast' (SynType.createLongIdent' [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonNode" ])
+
+                if innerIsJsonNode then
+                    target
+                else
+                    target
+                    |> SynExpr.paren
+                    |> SynExpr.upcast' (SynType.createLongIdent' [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonNode" ])
                 |> SynMatchClause.create (
                     SynPat.identWithArgs [ Ident.create "Some" ] (SynArgPats.create [ Ident.create "field" ])
                 )
@@ -57,6 +68,7 @@ module internal JsonSerializeGenerator =
             [ noneClause ; someClause ]
             |> SynExpr.createMatch (SynExpr.createIdent "field")
             |> SynExpr.createLambda "field"
+            |> fun e -> e, true
         | ArrayType ty
         | ListType ty ->
             // fun field ->
@@ -73,7 +85,7 @@ module internal JsonSerializeGenerator =
                     SynExpr.createIdent "field",
                     SynExpr.applyFunction
                         (SynExpr.createLongIdent [ "arr" ; "Add" ])
-                        (SynExpr.paren (SynExpr.applyFunction (serializeNode ty) (SynExpr.createIdent "mem"))),
+                        (SynExpr.paren (SynExpr.applyFunction (fst (serializeNode ty)) (SynExpr.createIdent "mem"))),
                     range0
                 )
                 SynExpr.createIdent "arr"
@@ -86,6 +98,7 @@ module internal JsonSerializeGenerator =
                     |> SynBinding.basic [ Ident.create "arr" ] []
                 ]
             |> SynExpr.createLambda "field"
+            |> fun e -> e, false
         | IDictionaryType (_keyType, valueType)
         | DictionaryType (_keyType, valueType)
         | IReadOnlyDictionaryType (_keyType, valueType)
@@ -113,7 +126,7 @@ module internal JsonSerializeGenerator =
                             [
                                 SynExpr.createLongIdent [ "key" ; "ToString" ]
                                 |> SynExpr.applyTo (SynExpr.CreateConst ())
-                                SynExpr.applyFunction (serializeNode valueType) (SynExpr.createIdent "value")
+                                SynExpr.applyFunction (fst (serializeNode valueType)) (SynExpr.createIdent "value")
                             ]),
                     range0
                 )
@@ -127,6 +140,7 @@ module internal JsonSerializeGenerator =
                     |> SynBinding.basic [ Ident.create "ret" ] []
                 ]
             |> SynExpr.createLambda "field"
+            |> fun e -> e, false
         | _ ->
             // {type}.toJsonNode
             let typeName =
@@ -134,7 +148,7 @@ module internal JsonSerializeGenerator =
                 | SynType.LongIdent ident -> ident.LongIdent
                 | _ -> failwith $"Unrecognised type: %+A{fieldType}"
 
-            SynExpr.createLongIdent' (typeName @ [ Ident.create "toJsonNode" ])
+            SynExpr.createLongIdent' (typeName @ [ Ident.create "toJsonNode" ]), true
 
     /// propertyName is probably a string literal, but it could be a [<Literal>] variable
     /// `node.Add ({propertyName}, {toJsonNode})`
@@ -142,7 +156,7 @@ module internal JsonSerializeGenerator =
         [
             propertyName
             SynExpr.pipeThroughFunction
-                (serializeNode fieldType)
+                (fst (serializeNode fieldType))
                 (SynExpr.createLongIdent' [ Ident.create "input" ; fieldId ])
             |> SynExpr.paren
         ]
@@ -286,7 +300,7 @@ module internal JsonSerializeGenerator =
                     let propertyName = getPropertyName (Option.get fieldData.Ident) fieldData.Attrs
 
                     let node =
-                        SynExpr.applyFunction (serializeNode fieldData.Type) (SynExpr.createIdent' caseName)
+                        SynExpr.applyFunction (fst (serializeNode fieldData.Type)) (SynExpr.createIdent' caseName)
 
                     [ propertyName ; node ]
                     |> SynExpr.tuple