Added FileData type instead of a Stream to provide a Content Type of a file (#532)

Author: ePasha

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

@@ -13,6 +13,7 @@ type HttpContextRequestExecutionContext (httpContext : HttpContext) =
             else
                 let form = httpContext.Request.Form
                 match (form.Files |> Seq.vtryFind (fun f -> f.Name = key)) with
-                | ValueSome file -> Ok (file.OpenReadStream())
+                | ValueSome file ->
+                    Ok { Stream = file.OpenReadStream (); ContentType = file.ContentType }
                 | ValueNone -> Error $"File with key '{key}' not found"
 

src/FSharp.Data.GraphQL.Shared/InputContext.fs

@@ -1,7 +1,12 @@
 namespace FSharp.Data.GraphQL
 
+type FileData = {
+    Stream : System.IO.Stream
+    ContentType : string
+}
+
 type IInputExecutionContext =
-    abstract GetFile : string -> Result<System.IO.Stream, string>
+    abstract GetFile : string -> Result<FileData, string>
 
 type InputExecutionContextProvider = unit -> IInputExecutionContext
 

src/FSharp.Data.GraphQL.Shared/SchemaDefinitions.fs

@@ -191,7 +191,7 @@ module SchemaDefinitions =
         | _ -> Some(x.ToString())
 
     /// Tries to convert any value to string.
-    let coerceFileValue (context : IInputExecutionContext) (value : obj) : Result<System.IO.Stream, string>  =
+    let coerceFileValue (context : IInputExecutionContext) (value : obj) : Result<FileData, string>  =
         match coerceStringValue value with
         | Some fileName -> context.GetFile fileName
         | None -> Error "Only string value can be used as file name"
@@ -482,31 +482,31 @@ module SchemaDefinitions =
           CoerceInput = coerceGuidInput
           CoerceOutput = coerceGuidValue }
 
-        /// Defines an object list filter for use as an argument for filter list of object fields.
-    let FileType : InputCustomDefinition<System.IO.Stream> = {
+    /// Defines an object list filter for use as an argument for filter list of object fields.
+    let FileType : InputCustomDefinition<FileData> = {
         Name = "FileType"
         Description =
             Some
                 "The `File` type represents a file on one or more fields of an object in an object list. The filter is represented by a JSON object where the fields are the complemented by specific suffixes to represent a query."
         CoerceInput =
             (fun inputContext input variables ->
-                let getFileStream fileKey =
+                let getFileData fileKey =
                     let inputExecutionContext = inputContext()
-                    let streamResult = inputExecutionContext.GetFile fileKey
-                    match streamResult with
-                    | Ok stream -> Ok stream
+                    let fileData = inputExecutionContext.GetFile fileKey
+                    match fileData with
+                    | Ok data -> Ok data
                     | Error errorMessage -> IGQLError.createResultErrorList errorMessage
 
                 match input with
                 | InlineConstant c ->
                     match c with
-                    | StringValue strValue -> getFileStream strValue
+                    | StringValue strValue -> getFileData strValue
                     | VariableName varName ->
-                        Ok (variables[varName] :?> System.IO.Stream)
+                        Ok (variables[varName] :?> FileData)
                     | _ -> IGQLError.createResultErrorList "Only a string value or a variable with a string value can be used as a file name."
                 | Variable json ->
                     match (json |> InputValue.OfJsonElement) with
-                    | StringValue str -> getFileStream str
+                    | StringValue str -> getFileData str
                     | _ -> IGQLError.createResultErrorList "Only a variable with a string value can be used as a file name.")
     }
 

tests/FSharp.Data.GraphQL.Tests/FileTests.fs

@@ -19,10 +19,15 @@ let QueryType =
     )
 
 type Input = {
-    File : Stream
-    File2 : Stream option
+    File : FileData
+    File2 : FileData option
 }
 
+let private getFullInfo fileData =
+    use reader = new StreamReader(fileData.Stream, Encoding.UTF8, true)
+    let fileContent = reader.ReadToEnd()
+    fileContent + fileData.ContentType
+
 let InputObject = Define.InputObject<Input>(
     name = "Input",
     fields =
@@ -37,21 +42,18 @@ let MutationType =
         fields =
             [ Define.Field ("uploadFile", StringType, "", [ Define.Input ("input", FileType) ],
                 (fun ctx () ->
-                    let stream = ctx.Arg<Stream> "input"
-                    use reader = new StreamReader(stream, Encoding.UTF8, true)
-                    reader.ReadToEnd()
+                    let fileData = ctx.Arg<FileData> "input"
+                    getFullInfo fileData
                 ));
                 Define.Field ("uploadFileComplex", StringType, "", [ Define.Input ("input", InputObject) ],
                 (fun ctx () ->
                     let input = ctx.Arg<Input> "input"
-                    let reader = new StreamReader(input.File, Encoding.UTF8, true)
-                    let fileContent = reader.ReadToEnd()
-                    let file2Content = match input.File2 with
+                    let fileString = getFullInfo input.File
+                    let file2String = match input.File2 with
                                         | Some file2 ->
-                                            let reader2 = new StreamReader(file2, Encoding.UTF8, true)
-                                            reader2.ReadToEnd()
+                                            getFullInfo file2
                                         | None -> ""
-                    fileContent + file2Content
+                    fileString + file2String
                 ))
             ]
     )
@@ -80,7 +82,7 @@ let mutationComplexObjectWithTwoFiles = """mutation uploadFile () {
 
 [<Fact>]
 let ``File type: Must upload file as input scalar using inline string as a file name`` () =
-    let expected = NameValueLookup.ofList [ "uploadFile", MockInputContext.mockFileText ]
+    let expected = NameValueLookup.ofList [ "uploadFile", MockInputContext.mockFileTextAndContentType ]
     let result = execute mutationWithConstant
     ensureDirect result <| fun data errors ->
             empty errors
@@ -89,7 +91,7 @@ let ``File type: Must upload file as input scalar using inline string as a file
 
 [<Fact>]
 let ``File type: Must upload a file as input scalar using a variable`` () =
-    let expected = NameValueLookup.ofList [ "uploadFile", MockInputContext.mockFileText ]
+    let expected = NameValueLookup.ofList [ "uploadFile", MockInputContext.mockFileTextAndContentType ]
     let jsonVariable = "\"fileKey\"" |> JsonDocument.Parse |> _.RootElement
     let variables = ImmutableDictionary<string, JsonElement>.Empty.Add ("file", jsonVariable)
     let result = executeWithVariables (mutationWithVariable, variables)
@@ -100,7 +102,7 @@ let ``File type: Must upload a file as input scalar using a variable`` () =
 
 [<Fact>]
 let ``File type: Must upload a file as input object field using inline string a file name`` () =
-    let expected = NameValueLookup.ofList [ "uploadFileComplex", MockInputContext.mockFileText ]
+    let expected = NameValueLookup.ofList [ "uploadFileComplex", MockInputContext.mockFileTextAndContentType ]
     let result = execute mutationComplexObject
     ensureDirect result <| fun data errors ->
             empty errors
@@ -109,7 +111,7 @@ let ``File type: Must upload a file as input object field using inline string a
 
 [<Fact>]
 let ``File type: Must upload two files as input object field using inline string a file name`` () =
-    let expectedContent = MockInputContext.mockFileText + MockInputContext.mockFileText2
+    let expectedContent = MockInputContext.mockFileTextAndContentType + MockInputContext.mockFileText2AndContentType
     let expected = NameValueLookup.ofList [
         "uploadFileComplex", expectedContent
     ]

tests/FSharp.Data.GraphQL.Tests/Helpers.fs

@@ -185,11 +185,15 @@ type ExecutorExtensions =
 
 module MockInputContext =
 
+    let mockContentType = System.Net.Mime.MediaTypeNames.Text.Plain
     let mockFileKey = "fileKey"
     let mockFileKey2 = "fileKey2"
     let mockFileText = "fileText"
     let mockFileText2 = "fileText2"
 
+    let mockFileTextAndContentType = mockFileText + mockContentType
+    let mockFileText2AndContentType = mockFileText2 + mockContentType
+
     type MockInputExecutionContext () =
 
         member _.FileKey = mockFileKey
@@ -207,9 +211,9 @@ module MockInputContext =
         interface IInputExecutionContext with
             member context.GetFile key =
                 if (key = context.FileKey) then
-                    Ok context.Stream
+                    Ok { Stream = context.Stream; ContentType = mockContentType }
                 else if (key = context.FileKey2) then
-                    Ok context.Stream2
+                    Ok { Stream = context.Stream2; ContentType = mockContentType }
                 else
                     failwith $"only file {context.FileKey} and file {context.FileKey2} exist"