custom json converters

graphql-ws.fsharp.sln

@@ -7,6 +7,10 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{2BBAEFA0-4E9
 EndProject
 Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "Main", "src\Main\Main.fsproj", "{72471B86-58DF-42DC-8220-4E9E658AE781}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "tests", "tests", "{E2ECB101-4BA2-4884-9AE2-012BF8F8F433}"
+EndProject
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "Main.UnitTests", "tests\unit-tests\Main.UnitTests.fsproj", "{85297F41-0524-400A-89EC-E4360CB033D9}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -20,8 +24,13 @@ Global
 		{72471B86-58DF-42DC-8220-4E9E658AE781}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{72471B86-58DF-42DC-8220-4E9E658AE781}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{72471B86-58DF-42DC-8220-4E9E658AE781}.Release|Any CPU.Build.0 = Release|Any CPU
+		{85297F41-0524-400A-89EC-E4360CB033D9}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{85297F41-0524-400A-89EC-E4360CB033D9}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{85297F41-0524-400A-89EC-E4360CB033D9}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{85297F41-0524-400A-89EC-E4360CB033D9}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{72471B86-58DF-42DC-8220-4E9E658AE781} = {2BBAEFA0-4E9F-467B-ABEA-A9854E821495}
+		{85297F41-0524-400A-89EC-E4360CB033D9} = {E2ECB101-4BA2-4884-9AE2-012BF8F8F433}
 	EndGlobalSection
 EndGlobal

src/Main/GraphQLWebsocketMiddleware.fs

@@ -46,7 +46,7 @@ module internal GraphQLSubscriptionsManagement =
 
 type GraphQLWebSocketMiddleware<'Root>(next : RequestDelegate, applicationLifetime : IHostApplicationLifetime, jsonOptions : IOptions<JsonOptions>, executor : Executor<'Root>, root : unit -> 'Root, url: string) =
 
-  let serializeServerMessage (jsonOptions: JsonOptions) obj =
+  let serializeServerMessage (jsonOptions: JsonOptions) serverMessage =
       task { return "dummySerializedServerMessage" }
 
   let deserializeClientMessage (jsonOptions: JsonOptions) (msg: string) =
@@ -153,6 +153,7 @@ type GraphQLWebSocketMiddleware<'Root>(next : RequestDelegate, applicationLifeti
     let logMsgWithIdReceived id msgAsStr =
         printfn "%s (id: %s)" msgAsStr id
 
+    let mutable socketClosed = false
     // <--------------
     // <-- Helpers --|
     // <--------------
@@ -162,7 +163,7 @@ type GraphQLWebSocketMiddleware<'Root>(next : RequestDelegate, applicationLifeti
     // ------->
     task {
       try
-          while not cancellationToken.IsCancellationRequested do
+          while not cancellationToken.IsCancellationRequested && not socketClosed do
               let! receivedMessage = safe_Receive()
               match receivedMessage with
               | None ->
@@ -192,7 +193,8 @@ type GraphQLWebSocketMiddleware<'Root>(next : RequestDelegate, applicationLifeti
                       do! Complete id |> safe_Send
                   | InvalidMessage explanation ->
                       "InvalidMessage" |> logMsgReceivedWithOptionalPayload None
-                      do! Error (None, explanation) |> safe_Send
+                      do! socket.CloseAsync(enum CustomWebSocketStatus.invalidMessage, explanation, cancellationToken)
+                      socketClosed <- true
       with // TODO: MAKE A PROPER GRAPHQL ERROR HANDLING!
       | ex ->
         printfn "Unexpected exception \"%s\" in GraphQLWebsocketMiddleware (handleMessages). More:\n%s" (ex.GetType().Name) (ex.ToString())

src/Main/JsonConverters.fs

@@ -0,0 +1,72 @@
+namespace GraphQLTransportWS
+
+open System
+open System.Text.Json
+open System.Text.Json.Serialization
+
+[<Sealed>]
+type WebSocketServerMessageConverter() =
+  inherit JsonConverter<WebSocketServerMessage>()
+
+  override  __.Read(reader: byref<Utf8JsonReader>, typeToConvert: Type, options: JsonSerializerOptions) =
+    ConnectionAck
+
+  override __.Write(writer: Utf8JsonWriter, value: WebSocketServerMessage, options: JsonSerializerOptions) =
+    let thenAddProperty (propName: string) (propStrValue: string) =
+      writer.WritePropertyName(propName)
+      writer.WriteStringValue(propStrValue)
+
+    let beginSerializedObjWith (propName: string) (propStrValue: string) =
+      writer.WriteStartObject()
+      thenAddProperty propName propStrValue
+
+    let endSerializedObj () =
+      writer.WriteEndObject()
+
+    let addOptionalPayloadProperty (optionalPayload: string option) =
+      match optionalPayload with
+      | Some p ->
+          thenAddProperty "payload" p
+      | None ->
+          ()
+
+    match value with
+    | Error (id, errs) ->
+        beginSerializedObjWith "type" "error"
+        thenAddProperty "id" id
+        writer.WriteStartArray("payload")
+        errs
+        |> List.iter
+            (fun err ->
+              writer.WriteStartObject()
+              writer.WritePropertyName("message")
+              writer.WriteStringValue(err)
+              writer.WriteEndObject()
+            )
+        writer.WriteEndArray()
+        endSerializedObj()
+    | ConnectionAck ->
+        beginSerializedObjWith "type" "connection_ack"
+        endSerializedObj()
+    | ServerPing p ->
+        beginSerializedObjWith "type" "ping"
+        addOptionalPayloadProperty p
+        endSerializedObj()
+    | ServerPong p ->
+        beginSerializedObjWith "type" "pong"
+        addOptionalPayloadProperty p
+        endSerializedObj()
+    | Next(id, result) ->
+        beginSerializedObjWith "type" "next"
+        thenAddProperty "id" id
+        writer.WritePropertyName("payload")
+        writer.WriteRawValue(JsonSerializer.Serialize(result), skipInputValidation = true)
+        endSerializedObj()
+    | Complete(id) ->
+        beginSerializedObjWith "type" "complete"
+        thenAddProperty "id" id
+        endSerializedObj()
+
+
+
+    // writer.WriteStartObject(propertyName = )

src/Main/Main.fsproj

@@ -13,6 +13,7 @@
     <Compile Include="Rop/Rop.fs" />
     <Compile Include="Rop/RopAsync.fs" />
     <Compile Include="WebSocketMessages.fs" />
+    <Compile Include="JsonConverters.fs" />
     <Compile Include="GraphQLWebsocketMiddleware.fs" />
     <Compile Include="Library.fs" />
   </ItemGroup>

src/Main/WebSocketMessages.fs

@@ -20,5 +20,8 @@ type WebSocketServerMessage =
     | ServerPing of payload: string option
     | ServerPong of payload: string option
     | Next of id : string * payload : Output
-    | Error of id : string option * err : string
-    | Complete of id : string
+    | Error of id : string * err : string list
+    | Complete of id : string
+
+module CustomWebSocketStatus =
+    let invalidMessage = 4400

tests/unit-tests/Main.UnitTests.fsproj

@@ -0,0 +1,32 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net7.0</TargetFramework>
+
+    <IsPackable>false</IsPackable>
+    <GenerateProgramFile>false</GenerateProgramFile>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="Tests.fs" />
+    <Compile Include="Program.fs" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.2" />
+    <PackageReference Include="xunit" Version="2.4.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="coverlet.collector" Version="3.1.2">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Main\Main.fsproj" />
+  </ItemGroup>
+
+</Project>

tests/unit-tests/Program.fs

@@ -0,0 +1 @@
+module Program = let [<EntryPoint>] main _ = 0

tests/unit-tests/Tests.fs

@@ -0,0 +1,30 @@
+module Tests
+
+open GraphQLTransportWS
+open System
+open System.Text.Json
+open Xunit
+
+[<Fact>]
+let ``Serializes ServerPing correctly`` () =
+    let jsonOptions = new JsonSerializerOptions()
+    jsonOptions.Converters.Add(new WebSocketServerMessageConverter())
+
+    let input: WebSocketServerMessage =
+        ServerPing (Some "Peekaboo!")
+
+    let result = JsonSerializer.Serialize(input, jsonOptions)
+
+    Assert.Equal("{\"type\":\"ping\",\"payload\":\"Peekaboo!\"}", result)
+
+[<Fact>]
+let ``Serializes Error correctly`` () =
+    let jsonOptions = new JsonSerializerOptions()
+    jsonOptions.Converters.Add(new WebSocketServerMessageConverter())
+
+    let input: WebSocketServerMessage =
+        Error ("myId", [ "An error ocurred during GraphQL execution" ])
+
+    let result = JsonSerializer.Serialize(input, jsonOptions)
+
+    Assert.Equal("{\"type\":\"error\",\"id\":\"myId\",\"payload\":[{\"message\":\"An error ocurred during GraphQL execution\"}]}", result)