`body` property not present on Response. Is `_bodyInit` spec compliant?

[Bob Ziroll]

I'll be the first to admit I'm a bit out of my depth here, so I'd love to better understand what's going on. TIA for your patience with my limited understanding 😅

I'm using a library (MirageJS) that uses Pretender, which uses whatwg-fetch. Pretender appears to be using this fetch polyfill whether the environment has a native fetch or not (another issue/PR I'm posting for them).

The reason it has become a problem for me is that React Router ≥ v6.4.5 started duck-type-checking the Response object that is being intercepted by Pretender (and molded by this polyfill), specifically looking for a property called body.

According to the Fetch Standard re: Responses, it appears a Response needs to have a body property to be compliant. However, as far as I can tell, this library always appends a property called _bodyInit instead of body. (This is where I'm seeing that)

_bodyInit is created by the _initBody method here

It seems to my uneducated-on-fetch-standards-and-responses self that it could be changed to something like

this.body = body

But again, I'm sure I'm just misunderstanding something, and would like to be shown the light. Or perhaps have a chance to submit a PR 😋

TIA for any guidance or help you can provide!

[Jake Champion]

Hi there, the body property is purposefully not implemented as this polyfill does not support ReadableStreams, which is what the body property is meant to be an instance of -- I'll be closing this as a duplicate of #746 - #1109 - #198 (comment)

If you would like to attempt a ReadableStream polyfill and adding a body property which uses that, I will be happy to review the code ☺️