Cannot add a header "Content-Type" in v107

[PusheadSG]

Describe the bug
Header "Content-Type" is not getting added to the request

To Reproduce
Make any RestSharp request, and .AddHeader("Content-Type", "blivelsnotch") to the request. Run the request and examine the data being sent. There will be no "Content-Type" header sent, no matter what value you enter. Change the spelling of "Content-Type" to "ContentType" and the header gets added.

Expected behavior
.AddHeader("Content-Type", "value") should add a header of "Content-Type" to the request.

Desktop (please complete the following information):

• OS: Windows 10
• .NET 5
• Version 107.1.1

[alexeyzimarev]

I fixed it locally. The issue is caused by the fact that Content-Type is the content header.

Also, please consider this: https://restsharp.dev/support/#content-type

[PusheadSG]

Thanks - I did note the Content-Type behavior based on what you are sending - when sending a file, will RestSharp add a Content-Type of multipart/form-data to the header when this gets fixed?

[alexeyzimarev]

Yes, but it's not what RestSharp does, it is how MultipartFormDataContent works (and all other derivatives of HttpContent). It already works as it should. What I fixed was adding content headers to the request content. But it is not needed in most cases. If you are sending a file and your request doesn't get the multipart form content type, I would ask you to trace the request using requestbin.com and ensure that's the case, because RestSharp has tests for file uploads, including the content type check.

[PusheadSG]

Agreed - not needed in most cases, but in this case, it's required - I'm uploading an image to Test Rail's API, and they require the request have Content-Type = multipart/form-data in the header when uploading the file. Why? Heaven only knows, but without it, you can't upload any attachments. I used HttpTracer and see that RestSharp is doing everything correctly in the request body, and it would probably work fine if Test Rail was not requiring what they do in the header, but we have no control over how they implement their restful API.

Thanks a ton for working on this.

[alexeyzimarev]

What I mean is that RestSharp always sets the content type to multipart form data when you add a file to the request. So, I am not sure what's wrong in your case.

[alexeyzimarev]

Actually, what I "fixed" was wrong. It was already working correctly. Both default content type and custom content type are correctly set from the beginning. We have a test for multipart form specifically, using a custom content type. After my "fix" it broke down. The published version works as it should. So, I'd need some reproduction as I believe it works correctly.

RestSharp/test/RestSharp.IntegrationTests/MultipartFormDataTests.cs

Lines 130 to 154 in 9913432

	[Fact]
	public async Task MultipartFormData_WithCustomContentType() {
	var request = new RestRequest("/", Method.Post);
	var path = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Assets", "TestFile.txt");
	const string customContentType = "multipart/vnd.resteasy+form-data";
	request.AddHeader(KnownHeaders.ContentType, customContentType);
	request.AddFile("fileName", path);
	request.AddParameter(new BodyParameter("controlName", "test", "application/json"));
	string boundary = null;
	request.OnBeforeRequest = http => {
	boundary = http.Content!.GetFormBoundary();
	return default;
	};
	var response = await _client.ExecuteAsync(request);
	var expectedFileAndBodyRequestContent = string.Format(ExpectedFileAndBodyRequestContent, boundary);
	var expectedCustomMultipartContentType = string.Format(ExpectedCustomMultipartContentType, boundary);
	response.Content.Should().Be(expectedFileAndBodyRequestContent);
	RequestHandler.CapturedContentType.Should().Be(expectedCustomMultipartContentType);
	}

[alexeyzimarev]

Again, with AddFile you should not set the multipart form data content type manually, as I mentioned in the docs.

[PusheadSG]

Here's my code that is making the file upload request:

              Request = new RestRequest("/index.php?/api/v2/add_attachment_to_result/122")
                                    //.AddHeader("Content-Type", "multipart/form-data")
                                    .AddFile("attachment", Screenshot);

               RestResponse AddAttachmentResponse = Client.PostAsync(Request).GetAwaiter().GetResult();

Here's the HttpTracer log content:

==================== HTTP REQUEST: [POST] ====================
POST https://foundationsource.testrail.io/index.php?/api/v2/add_attachment_to_result/122
Authorization: Basic Snipped
Accept: application/json, text/json, text/x-json, text/javascript, *+json, application/xml, text/xml, *+xml, *
User-Agent: RestSharp/107.1.1.0
Cookie: tr_session=4f0d86da-7b93-4ba7-9842-a29e3cc1f58c
--a9439ed1-e7ac-43e9-9a0d-ec270119cade
Content-Type: application/octet-stream
Content-Disposition: form-data; name=attachment; filename=Untitled.png; filename*=utf-8''Untitled.png

?PNG
→
IHDR

☻☻PX?☺sRGB??∟?♦gAMA??♂?a♣       pHYs♫?♫?☺?o?d↑IDAT(Sc?_??Ai∟`dJ30lH☻♀Z↔T☼IEND?B`?
--a9439ed1-e7ac-43e9-9a0d-ec270119cade--

There is a Content-Type in the body "application/octet-stream" but no Content-Type in the header.

[PusheadSG]

Here's a sample where I'm using AddJsonBody:

RestRequest Request = new RestRequest("/ws/rest/dev/session") 
    .AddHeader("Accept", "application/vnd.api+json")
    .AddJsonBody(Creds, "application/vnd.api+json");

RestResponse r = await Client.PostAsync(Request);

Here's the HttpTrace output. Note, no Content-Type in the header:
==================== HTTP REQUEST: [POST] ====================
POST https://online.qa1.fs.local/ws/rest/dev/session
Accept: application/vnd.api+json
User-Agent: RestSharp/107.0.3.0
{"data":{"type":"session","id":null,"attributes":{"auth-id":0,"auth-name":"UserNameHere","user-id":0,"name":null,"status":null,"role-id":0,"ext-id":0,"password":"NoPasswordHere"}}}

[alexeyzimarev]

Yeah, I have seen it too. But the header is set, believe it or not.

The reason that you don't see it is that HttpTracer only looks at request headers, but not at content headers. So, headers like Content-Type, Content-Encoding, Content-Length, Content-Disposition are all not there, but there are part of the request.

THAT'S WHY (sorry) I asked to check with requestbin.com.

[PusheadSG]

I'll see if I can get requestbin set up

[alexeyzimarev]

It's an online service.

[alexeyzimarev]

Also, it's easier to set the AcceptedContentTypes property for the client instead of adding the Accept header all the time.

Your JSON request looks totally legit, I hope it works.

[PusheadSG]

The JSON is working fine - I'm just going to have to spend time is getting a requestbin integration up - I'm in over my head there...