`Response.redirect` should return object whose headers are mutable, as well as `Response.json`

[petamoriken]

What is the issue with the Fetch Standard?

Response.json returns an object whose headers are mutable, but Response.error/ Response.redirect currently return immutable ones. This is inconsistent; all should be mutable.

The static json(data, init) method steps are:

3. Let responseObject be the result of creating a Response object, given a new response, "response", and the current realm.

https://fetch.spec.whatwg.org/#dom-response-json

The static redirect(url, status) method steps are:

4. Let responseObject be the result of creating a Response object, given a new response, "immutable", and the current realm.

https://fetch.spec.whatwg.org/#dom-response-redirect

[annevk]

I don't really see how this makes sense for error(). (error() is a bit weird since it really represents the lack of a response.)

[petamoriken]

I don't really see how this makes sense for error(). (error() is a bit weird since it really represents the lack of a response.)

I changed this issue to target only Response.redirect.

[annevk]

Since you can create the exact same responses using new Response(), I think all that's required here is a Fetch and WPT PR. I suppose in theory implementations could oppose this change, but that doesn't seem realistic. You can count WebKit as supportive in any event.