WIP: "deserializing" client subscribe request

  Coming next: variables (and extensions?)"

src/Main/JsonConverters.fs

@@ -20,15 +20,40 @@ type GraphQLWsMessageConverter() =
     else
       failwithf "was expecting a value for property \"%s\"" propertyName
 
+  let readSubscribePayload (reader : byref<Utf8JsonReader>) : GraphQLWsMessageSubscribePayloadRaw =
+    let mutable operationName : string option = None
+    let mutable query : string option = None
+    let mutable variables : string option = None
+    let mutable extensions : string option = None
+    while reader.Read() && (not <| reader.TokenType.Equals(JsonTokenType.EndObject)) do
+      match reader.GetString() with
+      | "operationName" ->
+        operationName <- readPropertyValueAsAString "operationName" &reader
+      | "query" ->
+        query <- readPropertyValueAsAString "query" &reader
+      | "variables" ->
+        variables <- readPropertyValueAsAString "variables" &reader
+      | "extensions" ->
+        extensions <- readPropertyValueAsAString "extensions" &reader
+      | other ->
+        failwithf "unexpected property \"%s\" in payload object" other
+    { OperationName = operationName
+      Query = query
+      Variables = variables
+      Extensions = extensions }
+
   let readPayload (reader : byref<Utf8JsonReader>) : GraphQLWsMessagePayloadRaw option =
     if reader.Read() then
       if reader.TokenType.Equals(JsonTokenType.String) then
         StringPayload (reader.GetString())
         |> Some
+      elif reader.TokenType.Equals(JsonTokenType.StartObject) then
+        SubscribePayload (readSubscribePayload &reader)
+        |> Some
       elif reader.TokenType.Equals(JsonTokenType.Null) then
         failwith "was expecting a value for property \"payload\""
       else
-        None
+        failwith "Not implemented yet. Uh-oh, this is a bug."
     else
       failwith "was expecting a value for property \"payload\""
 

src/Main/WebSocketMessagesMappers.fs

@@ -1,6 +1,12 @@
 namespace GraphQLTransportWS
 
 module GraphQLWsMessageRawMapping =
+  open FSharp.Data.GraphQL
+
+  let requireId (raw : GraphQLWsMessageRaw) : string =
+    match raw.Id with
+    | Some s -> s
+    | None -> failwith "property \"id\" is required but was not there"
 
   let requirePayloadToBeAnOptionalString (payload : GraphQLWsMessagePayloadRaw option) : string option =
     match payload with
@@ -10,12 +16,23 @@ module GraphQLWsMessageRawMapping =
       | _ -> failwith "payload was expected to be a string, but it wasn't"
     | None -> None
 
-  let requireId (raw : GraphQLWsMessageRaw) : string =
-    match raw.Id with
-    | Some s -> s
-    | None -> failwith "property \"id\" is required but was not there"
+  let requireSubscribePayload (executor : Executor<'a>) (payload : GraphQLWsMessagePayloadRaw option) : GraphQLQuery =
+    match payload with
+    | Some p ->
+      match p with
+      | SubscribePayload rawSubsPayload ->
+        match rawSubsPayload.Query with
+        | Some query ->
+          { ExecutionPlan = executor.CreateExecutionPlan(query)
+            Variables = Map.empty }
+        | None ->
+          failwith "there was no query in subscribe message!"
+      | _ ->
+        failwith "payload was expected to be a subscribe payload object, but it wasn't."
+    | None ->
+      failwith "payload is required for this message, but none was available"
 
-  let toWebSocketClientMessage (raw : GraphQLWsMessageRaw) : WebSocketClientMessage =
+  let toWebSocketClientMessage (executor : Executor<'a>) (raw : GraphQLWsMessageRaw) : WebSocketClientMessage =
     match raw.Type with
     | None ->
       failwithf "property \"type\" was not found in the client message"
@@ -27,6 +44,10 @@ module GraphQLWsMessageRawMapping =
       ClientPong (raw.Payload |> requirePayloadToBeAnOptionalString)
     | Some "complete" ->
       ClientComplete (raw |> requireId)
+    | Some "subscribe" ->
+      let id = raw |> requireId
+      let payload = raw.Payload |> requireSubscribePayload executor
+      Subscribe (id, payload)
     | Some other ->
       failwithf "type \"%s\" is not supported as a client message type" other
 

tests/unit-tests/Main.UnitTests.fsproj

@@ -8,6 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <Compile Include="TestSchema.fs" />
     <Compile Include="SerializationTests.fs" />
     <Compile Include="Program.fs" />
   </ItemGroup>

tests/unit-tests/SerializationTests.fs

@@ -1,9 +1,11 @@
 module Tests
 
+open UnitTest
 open GraphQLTransportWS
 open System
 open System.Text.Json
 open Xunit
+open FSharp.Data.GraphQL.Ast
 
 [<Fact>]
 let ``Serializes ServerPing correctly`` () =
@@ -37,7 +39,9 @@ let ``Deserializes ConnectionInit correctly`` () =
     let input = "{\"type\":\"connection_init\"}"
 
     let resultRaw = JsonSerializer.Deserialize<GraphQLWsMessageRaw>(input, serializerOptions)
-    let result = resultRaw |> GraphQLWsMessageRawMapping.toWebSocketClientMessage
+    let result =
+        resultRaw
+        |> GraphQLWsMessageRawMapping.toWebSocketClientMessage (TestSchema.executor)
 
     match result with
     | ConnectionInit None -> () // <-- expected
@@ -52,7 +56,9 @@ let ``Deserializes ConnectionInit with payload correctly`` () =
     let input = "{\"type\":\"connection_init\", \"payload\":\"hello\"}"
 
     let resultRaw = JsonSerializer.Deserialize<GraphQLWsMessageRaw>(input, serializerOptions)
-    let result = resultRaw |> GraphQLWsMessageRawMapping.toWebSocketClientMessage
+    let result =
+        resultRaw
+        |> GraphQLWsMessageRawMapping.toWebSocketClientMessage (TestSchema.executor)
 
     match result with
     | ConnectionInit (Some "hello") -> () // <-- expected
@@ -67,7 +73,9 @@ let ``Deserializes ClientPing correctly`` () =
     let input = "{\"type\":\"ping\"}"
 
     let resultRaw = JsonSerializer.Deserialize<GraphQLWsMessageRaw>(input, serializerOptions)
-    let result = resultRaw |> GraphQLWsMessageRawMapping.toWebSocketClientMessage
+    let result =
+        resultRaw
+        |> GraphQLWsMessageRawMapping.toWebSocketClientMessage (TestSchema.executor)
 
     match result with
     | ClientPing None -> () // <-- expected
@@ -82,7 +90,9 @@ let ``Deserializes ClientPing with payload correctly`` () =
     let input = "{\"type\":\"ping\", \"payload\":\"ping!\"}"
 
     let resultRaw = JsonSerializer.Deserialize<GraphQLWsMessageRaw>(input, serializerOptions)
-    let result = resultRaw |> GraphQLWsMessageRawMapping.toWebSocketClientMessage
+    let result =
+        resultRaw
+        |> GraphQLWsMessageRawMapping.toWebSocketClientMessage (TestSchema.executor)
 
     match result with
     | ClientPing (Some "ping!") -> () // <-- expected
@@ -97,7 +107,9 @@ let ``Deserializes ClientPong correctly`` () =
     let input = "{\"type\":\"pong\"}"
 
     let resultRaw = JsonSerializer.Deserialize<GraphQLWsMessageRaw>(input, serializerOptions)
-    let result = resultRaw |> GraphQLWsMessageRawMapping.toWebSocketClientMessage
+    let result =
+        resultRaw
+        |> GraphQLWsMessageRawMapping.toWebSocketClientMessage (TestSchema.executor)
 
     match result with
     | ClientPong None -> () // <-- expected
@@ -112,7 +124,9 @@ let ``Deserializes ClientPong with payload correctly`` () =
     let input = "{\"type\":\"pong\", \"payload\": \"pong!\"}"
 
     let resultRaw = JsonSerializer.Deserialize<GraphQLWsMessageRaw>(input, serializerOptions)
-    let result = resultRaw |> GraphQLWsMessageRawMapping.toWebSocketClientMessage
+    let result =
+        resultRaw
+        |> GraphQLWsMessageRawMapping.toWebSocketClientMessage (TestSchema.executor)
 
     match result with
     | ClientPong (Some "pong!") -> () // <-- expected
@@ -127,10 +141,69 @@ let ``Deserializes ClientComplete correctly``() =
     let input = "{\"id\": \"65fca2b5-f149-4a70-a055-5123dea4628f\", \"type\":\"complete\"}"
 
     let resultRaw = JsonSerializer.Deserialize<GraphQLWsMessageRaw>(input, serializerOptions)
-    let result = resultRaw |> GraphQLWsMessageRawMapping.toWebSocketClientMessage
+    let result =
+        resultRaw
+        |> GraphQLWsMessageRawMapping.toWebSocketClientMessage (TestSchema.executor)
 
     match result with
     | ClientComplete id ->
         Assert.Equal("65fca2b5-f149-4a70-a055-5123dea4628f", id)
     | other ->
         Assert.Fail(sprintf "unexpected actual value: '%A'" other)
+
+[<Fact>]
+let ``Deserializes client subscription correctly`` () =
+    let serializerOptions = new JsonSerializerOptions()
+    serializerOptions.Converters.Add(new GraphQLWsMessageConverter())
+
+    let input =
+        """{
+            "id": "b5d4d2ff-d262-4882-a7b9-d6aec5e4faa6",
+            "type": "subscribe",
+            "payload" : {
+                "query": "subscription { watchMoon(id: \"1\") { id name isMoon } }"
+            }
+           }
+        """
+
+    let resultRaw = JsonSerializer.Deserialize<GraphQLWsMessageRaw>(input, serializerOptions)
+    let result =
+        resultRaw
+        |> GraphQLWsMessageRawMapping.toWebSocketClientMessage (TestSchema.executor)
+
+    match result with
+    | Subscribe (id, payload) ->
+        Assert.Equal("b5d4d2ff-d262-4882-a7b9-d6aec5e4faa6", id)
+        Assert.Equal(1, payload.ExecutionPlan.Operation.SelectionSet.Length)
+        let watchMoonSelection = payload.ExecutionPlan.Operation.SelectionSet |> List.head
+        match watchMoonSelection with
+        | Field watchMoonField ->
+            Assert.Equal("watchMoon", watchMoonField.Name)
+            Assert.Equal(1, watchMoonField.Arguments.Length)
+            let watchMoonFieldArg = watchMoonField.Arguments |> List.head
+            Assert.Equal("id", watchMoonFieldArg.Name)
+            match watchMoonFieldArg.Value with
+            | StringValue theValue ->
+                Assert.Equal("1", theValue)
+            | other ->
+                Assert.Fail(sprintf "expected arg to be a StringValue, but it was: %A" other)
+            Assert.Equal(3, watchMoonField.SelectionSet.Length)
+            match watchMoonField.SelectionSet.[0] with
+            | Field firstField ->
+                Assert.Equal("id", firstField.Name)
+            | other ->
+                Assert.Fail(sprintf "expected field to be a Field, but it was: %A" other)
+            match watchMoonField.SelectionSet.[1] with
+            | Field secondField ->
+                Assert.Equal("name", secondField.Name)
+            | other ->
+                Assert.Fail(sprintf "expected field to be a Field, but it was: %A" other)
+            match watchMoonField.SelectionSet.[2] with
+            | Field thirdField ->
+                Assert.Equal("isMoon", thirdField.Name)
+            | other ->
+                Assert.Fail(sprintf "expected field to be a Field, but it was: %A" other)
+        | somethingElse ->
+            Assert.Fail(sprintf "expected it to be a field, but it was: %A" somethingElse)
+    | other ->
+        Assert.Fail(sprintf "unexpected actual value: '%A" other)