Hello! Can anyone please tell me if anybody has experience sending requests with Content-Type

"application/octet-stream"

(pact-js library) and verification on the provider side with C# language (pact-net library)? Because of many of my attempts, the response is 200 on the provider side, but when I try to test HTTP 400 Bad Request, I cannot find a suitable

withRequest

body for that test.

test("...", async () => {
                const badRequestData = {
                    error: {
                        code: "validationError",
                        message: "Validation error(s) has occurred",
                        details: [],
                    },
                };
                const badRequestResponse = somethingLike({
                    error: {
                        code: like(badRequestData.error.code),
                        message: like(badRequestData.error.message),
                        details: like(badRequestData.error.details),
                    },
                });
                const status = 400;

                await provider.addInteraction({
                    state: "...",
                    uponReceiving: "...",
                    withRequest: { method, headers, path, body: "\u0000" },
                    willRespondWith: { status, body: badRequestResponse },
                });
                expect.assertions(3);
                try {
                    await testService.sendContent(mailboxId, content);
                } catch (e) {
                    checkIfHttpError(e, status);
                    expect((e as AxiosError).response?.data).toStrictEqual(badRequestData);
                }
            });

[ApiController]
[Route("test")]
public class TestController : ControllerBase
{
    private readonly ITestService _testService;

    public TestController(ITestService testService)
    {
        _testService = testService;
    }

    [HttpPost("...")]
    [Authorize(...)]
    [Produces("application/json")]
    [Consumes("application/octet-stream")]
    [ProducesResponseType(type: typeof(TestResponse), StatusCodes.Status200OK)]
    [ProducesResponseType(StatusCodes.Status400BadRequest)]
    [ProducesResponseType(StatusCodes.Status401Unauthorized)]
    [ProducesResponseType(StatusCodes.Status500InternalServerError)]
    public async Task<TestResponse> HandleAsync(string id, [FromQuery(Name = "fileName")] string? fileName)
    {
        if (Request.ContentLength == 0)
        {
            throw new InvalidArgumentException("Request body should not be empty");
        }

        var messageId = await _testService.HandleAsync(id: id.ToLower().Trim(), fileName, Request.Body);

        return new TestResponse(messageId);
    }
}

What’s the issue with the

400

use case?

Sorry for the long time to answer. The issue is more related to the Axios library. It would be great if you, Matt, could help me deal with that. Because for now, it is a real blocking issue for our team. The main problem is sending an empty object with the type ArrayBuffer in the body and "application/octet-stream" as a content type request in the contract test - to get a validation error from the provider. To get such a response from the .NET part - the request content length should be zero. But all of my attempts to send, such as ArrayBuffer(0), don't represent Request with zero content type on the provider side, and as a result - API is trying to do some domain logic with this data returns 200 as well

No problems. I’m not sure I can give you an answer without detailed exploration on ArrayBuffers. Could you just omit the binary content altogether?

Maybe, but it is a part of our actual business logic case, which calls for sending empty files from consumers. Omit from binary content we cannot do because it must be in the protocol of our system. Most possible that I should manually find which is request body sending in UI during that case and pass them in our contract test

Well, what is an empty array buffer? It’s 0 bytes of data

You're right; I didn't even think about that

Yeah, I think the main confidence you want to get here, is that your consumer can handle a

400

. You could do that with provider states, and be agnostic to how the

400

happened (but it’s a bit clunky for the provider). You should definitely functionally test the provider for its validation use cases, but these belong in the provider code base

I understand. Thank you very much, Matt! 🙂

You’re welcome!