Cannot mock 204 response

Describe the bug

It seems to be impossible to construct a 204 (No content) response. When I just invoke return res(ctx.status(204)) I get the following error: Failed to construct ‘Response’: Response with null body status cannot have body It does not help trying to add ctx.json({}) or ctx.body(null) - the body seems to end up as the empty string regardless. This fails when msw is trying to invoke const response = new Response(payload.body, payload) in the function createResponseListener as responses with status 204 are not allowed to have any body.

Environment

msw: 0.25.0
Chrome: 87.0.4280.141

Issue Analytics

State:
Created 3 years ago
Comments:6 (3 by maintainers)

Top GitHub Comments

2reactions

SerkanSipahicommented, Jun 18, 2021

@kettanaito

You are right. It was my mistake. The 204 response contained an empty ( {} ) body payload in my case. As you suggested res(ctx.status(204)) is the right way here.

Thank you for your support and time.

2reactions

kettanaitocommented, Jun 18, 2021

Hi, @SerkanSipahi. The change you’re referencing has been successfully merged:

https://github.com/mswjs/msw/blob/9a43bc9cba49f3c18b1ab1ed700d3f41f9fe86f5/src/mockServiceWorker.js#L129-L130

Could you please ensure you’re running msw@0.29.0?

# To verify
$ npm ls msw

## To install latest
$ npm install msw@latest

In my case status-code 204 with a json response produces exactly the same error

Perhaps the response you’re composing is not a valid HTTP response? A response with a 204 status code cannot have a response body, that’d be a violation of the spec. Can you please try composing a mocked 204 response without any response body?

return res(ctx.status(204))

Top Results From Across the Web

How do I unit test an Angular HttpClient 204 response?

So, the simple answer is, pass '' to flush(): request.flush('', { status: 204, statusText: 'No Data' });.

Issue with REST Mockservice Response, when respons...

When the HTTP status code in the mock response is set to "204 - No Content", then no response is sent back from...

HTTP Status 204 (No Content) - REST

By default, 204 (No Content) the response is cacheable. If caching needs to be overridden then the response must include cache respective cache ......

Null API Responses and HTTP 204 Results in ASP.NET Core

ASP.NET Core 3.x has a behavior that results in API results that return null from the controller action returning a HTTP 204 -...

204 No Content - HTTP - MDN Web Docs - Mozilla

The HTTP 204 No Content success status response code indicates that a request has succeeded, but that the client doesn't need to navigate ......