Fixed IInputExecutionContext resolution (#539)

Author: VectorTetra

src/FSharp.Data.GraphQL.Server.AspNetCore/GraphQLRequestHandler.fs

@@ -6,6 +6,7 @@ open System.Text.Json
 open System.Text.Json.Serialization
 open System.Threading.Tasks
 open Microsoft.AspNetCore.Http
+open Microsoft.Extensions.DependencyInjection
 open Microsoft.Extensions.Logging
 open Microsoft.Extensions.Options
 
@@ -43,7 +44,7 @@ and [<AbstractClass>] GraphQLRequestHandler<'Root>
     ) =
 
     let ctx = httpContextAccessor.HttpContext
-    let getInputContext() = (HttpContextRequestExecutionContext ctx) :> IInputExecutionContext
+    let getInputContext() = ctx.RequestServices.GetRequiredService<IInputExecutionContext>()
 
     let toResponse { DocumentId = documentId; Content = content; Metadata = metadata } =
 

src/FSharp.Data.GraphQL.Server.AspNetCore/GraphQLWebsocketMiddleware.fs

@@ -11,6 +11,7 @@ open System.Text.Json.Serialization
 open System.Threading
 open System.Threading.Tasks
 open Microsoft.AspNetCore.Http
+open Microsoft.Extensions.DependencyInjection
 open Microsoft.Extensions.Hosting
 open Microsoft.Extensions.Logging
 open Microsoft.Extensions.Options
@@ -168,7 +169,6 @@ type GraphQLWebSocketMiddleware<'Root>
 
         let sendMsg = sendMessageViaSocket serializerOptions socket
         let rcv () = socket |> rcvMsgViaSocket serializerOptions
-        let getInputContext() = (HttpContextRequestExecutionContext httpContext) :> IInputExecutionContext
 
         let sendOutput id (output : SubscriptionExecutionResult) =
             sendMsg (Next (id, output))
@@ -273,6 +273,7 @@ type GraphQLWebSocketMiddleware<'Root>
                                         )
                                 else
                                     let variables = query.Variables |> Skippable.toOption
+                                    let getInputContext() = httpContext.RequestServices.GetRequiredService<IInputExecutionContext>()
                                     let! planExecutionResult =
                                         let root = options.RootFactory httpContext
                                         options.SchemaExecutor.AsyncExecute (query.Query, getInputContext, root, ?variables = variables)

src/FSharp.Data.GraphQL.Server.AspNetCore/RequestExecutionContext.fs

@@ -4,15 +4,17 @@ open System.IO
 open FSharp.Data.GraphQL
 open Microsoft.AspNetCore.Http
 
-type HttpContextRequestExecutionContext (httpContext : HttpContext) =
+type HttpContextRequestExecutionContext (httpContext : IHttpContextAccessor) =
 
     interface IInputExecutionContext with
 
         member this.GetFile (key) =
-            if not httpContext.Request.HasFormContentType then
+            let context = httpContext.HttpContext
+            if not context.Request.HasFormContentType then
+
                 Error "Request does not have form content type"
             else
-                let form = httpContext.Request.Form
+                let form = context.Request.Form
                 match (form.Files |> Seq.vtryFind (fun f -> f.Name = key)) with
                 | ValueSome file ->
                     let memoryStream = new MemoryStream ()