feat: handle text/plain payload types (#276)

* Add a test controller which consumes text/plain content

* feat: call new endpoint

* feat: add plain text support fot request payload

* feat: add plain text input formatter

* fix: input formatter order

* fix: canread on formatter

---------

Co-authored-by: Sergey Tihon <[email protected]>

Author: Numpsy

src/SwaggerProvider.DesignTime/v3/OperationCompiler.fs

@@ -28,6 +28,7 @@ type PayloadType =
     | AppOctetStream
     | AppFormUrlEncoded
     | MultipartFormData
+    | TextPlain
 
     override x.ToString() =
         match x with
@@ -36,6 +37,7 @@ type PayloadType =
         | AppOctetStream -> "octetStream"
         | AppFormUrlEncoded -> "formUrlEncoded"
         | MultipartFormData -> "formData"
+        | TextPlain -> "textPlain"
 
     member x.ToMediaType() =
         match x with
@@ -44,6 +46,7 @@ type PayloadType =
         | AppOctetStream -> MediaTypes.ApplicationOctetStream
         | AppFormUrlEncoded -> MediaTypes.ApplicationFormUrlEncoded
         | MultipartFormData -> MediaTypes.MultipartFormData
+        | TextPlain -> MediaTypes.TextPlain
 
     static member Parse =
         function
@@ -52,6 +55,7 @@ type PayloadType =
         | "octetStream" -> AppOctetStream
         | "formUrlEncoded" -> AppFormUrlEncoded
         | "formData" -> MultipartFormData
+        | "textPlain" -> TextPlain
         | name -> failwithf $"Payload '%s{name}' is not supported"
 
 /// Object for compiling operations.
@@ -114,6 +118,7 @@ type OperationCompiler(schema: OpenApiDocument, defCompiler: DefinitionCompiler,
                     | MediaType MediaTypes.ApplicationOctetStream mediaTyObj -> formatAndParam AppOctetStream mediaTyObj.Schema
                     | MediaType MediaTypes.MultipartFormData mediaTyObj -> formatAndParam MultipartFormData mediaTyObj.Schema
                     | MediaType MediaTypes.ApplicationFormUrlEncoded mediaTyObj -> formatAndParam AppFormUrlEncoded mediaTyObj.Schema
+                    | MediaType MediaTypes.TextPlain mediaTyObj -> formatAndParam TextPlain mediaTyObj.Schema
                     | NoMediaType ->
                         // Assume that server treat it as `applicationJson`
                         let defSchema = OpenApiSchema() // todo: we need to test it
@@ -359,6 +364,13 @@ type OperationCompiler(schema: OpenApiDocument, defCompiler: DefinitionCompiler,
                                     msg.Content <- RuntimeHelpers.toFormUrlEncodedContent(data)
                                     msg
                                 @>
+                            | Some(TextPlain, textObj) ->
+                                <@
+                                    let text = (%%textObj: obj).ToString()
+                                    let msg = %httpRequestMessage
+                                    msg.Content <- RuntimeHelpers.toTextContent(text)
+                                    msg
+                                @>
 
                         let action =
                             <@ (%this).CallAsync(%httpRequestMessageWithPayload, errorCodes, errorDescriptions) @>

src/SwaggerProvider.Runtime/RuntimeHelpers.fs

@@ -18,6 +18,9 @@ module MediaTypes =
     [<Literal>]
     let MultipartFormData = "multipart/form-data"
 
+    [<Literal>]
+    let TextPlain = "text/plain"
+
 type AsyncExtensions() =
     static member cast<'t> asyncOp =
         async {
@@ -127,6 +130,9 @@ module RuntimeHelpers =
     let toStringContent(valueStr: string) =
         new StringContent(valueStr, Text.Encoding.UTF8, "application/json")
 
+    let toTextContent(valueStr: string) =
+        new StringContent(valueStr, Text.Encoding.UTF8, "text/plain")
+
     let toStreamContent(boxedStream: obj) =
         match boxedStream with
         | :? IO.Stream as stream -> new StreamContent(stream)

tests/SwaggerProvider.ProviderTests/v3/Swashbuckle.ReturnTextControllers.Tests.fs

@@ -15,3 +15,7 @@ let ``Return text/plain GET Test``() =
 [<Fact>]
 let ``Return text/csv GET Test``() =
     api.GetApiReturnCsv() |> asyncEqual "Hello,world"
+
+[<Fact>]
+let ``Send & return text/plain POST Test``() =
+    api.PostApiConsumesText("hello") |> asyncEqual "hello"

tests/Swashbuckle.WebApi.Server/Controllers/ReturnTextControllers.fs

@@ -1,6 +1,8 @@
 namespace Swashbuckle.WebApi.Server.Controllers
 
+open System.IO
 open System.Text
+open System.Threading.Tasks
 open Microsoft.AspNetCore.Mvc
 open Microsoft.AspNetCore.Mvc.Formatters
 open Swagger.Internal
@@ -19,6 +21,13 @@ type ReturnCsvController() =
     member this.Get() =
         "Hello,world" |> ActionResult<string>
 
+[<Route("api/[controller]")>]
+[<ApiController>]
+type ConsumesTextController() =
+    [<HttpPost; Consumes("text/plain"); Produces("text/plain")>]
+    member this.Post([<FromBody>] request: string) =
+        request |> ActionResult<string>
+
 // Simple CSV output formatter
 // This formatter assumes the controller returns a string (already CSV-formatted)
 type CsvOutputFormatter() as this =
@@ -38,3 +47,22 @@ type CsvOutputFormatter() as this =
         let value = context.Object :?> string
         let bytes = encoding.GetBytes(value)
         response.Body.WriteAsync(bytes, 0, bytes.Length)
+
+// Text/plain input formatter for reading plain text request bodies
+type TextPlainInputFormatter() as this =
+    inherit TextInputFormatter()
+
+    do
+        this.SupportedMediaTypes.Add("text/plain")
+        this.SupportedEncodings.Add(Encoding.UTF8)
+        this.SupportedEncodings.Add(Encoding.Unicode)
+
+    override this.CanRead(context) =
+        base.CanRead(context) && context.ModelType = typeof<string>
+
+    override _.ReadRequestBodyAsync(context, encoding) =
+        task {
+            use reader = new StreamReader(context.HttpContext.Request.Body, encoding)
+            let! content = reader.ReadToEndAsync()
+            return InputFormatterResult.Success(content)
+        }

tests/Swashbuckle.WebApi.Server/Startup.fs

@@ -24,7 +24,9 @@ type Startup private () =
                 let converters = options.JsonSerializerOptions.Converters
                 converters.Add(JsonFSharpConverter())
                 converters.Add(JsonStringEnumConverter()))
-            .AddMvcOptions(_.OutputFormatters.Add(CsvOutputFormatter()))
+            .AddMvcOptions(fun options ->
+                options.OutputFormatters.Add(CsvOutputFormatter())
+                options.InputFormatters.Add(TextPlainInputFormatter()))
         |> ignore
         // Register the Swagger & OpenApi services
         services.AddSwaggerGen(fun c ->