version 3.6.0 breaks Electron 80 (Chromium 80)

[hans2520]

Verified that POST request works prior to upgrading to whatwg-fetech 3.6.0. Behavior the same with 3.6.1. Afterwards, with no other changes, we can see server receive Content-Length of 0 and empty body.

I found the offending line of code, simply commenting it out fixes things:
5c6b055#r47472637

The branch system above is quite convoluted, but I think if you can ensure the original body is preserved when you assign here, things will still work. From what I can tell, my code was hitting the final branch (5c6b055#diff-3fc6f1265a180d15035618e36ca1da88d092bacb4fc10a423938fa62e4f5f58fR246) and body being re-assigned there. But I tried a simple case of removing the body assignment there, and using body as the assignment instead on line 262, but it doesn't work. Making a new variable var origBody = body at the top of the branches and assigning that on line 262 does work however.

So probably want to look at cleaning up those branches. In the meantime, will be stuck at v3.5

[JakeChampion]

Could you please post a small piece of code which would reproduce the problem you are seeing? With a small example, I should be able to help fix this issue. Without one, I will struggle a lot.

[hans2520]

Well the issue seems to be with this line of code (line 246) because we are modifying the contents of body & _bodyText: 5c6b055#diff-3fc6f1265a180d15035618e36ca1da88d092bacb4fc10a423938fa62e4f5f58fR246

Then you are saying you are going to "save" the original body content into _bodyInit, but by this time it isn't true that body & _bodyText have the original contents. In fact it seems that in my case, the original contents of _bodyInit were already correct, and what's being assigned in line 246 is in fact wiping body and _bodyInit out entirely and that's why an empty body is sent to the server with this change.

SImply making this assignment on line 227 (
5c6b055#diff-3fc6f1265a180d15035618e36ca1da88d092bacb4fc10a423938fa62e4f5f58fR227), a new line:

var origBody = body

Then changing line 262 (5c6b055#diff-3fc6f1265a180d15035618e36ca1da88d092bacb4fc10a423938fa62e4f5f58fR262) to

 this._bodyInit = origBody

Also fixes the issue.

However, that is very much a hack for what is a very convoluted conditional branch tree that really should just be re-worked altogether. There's too much leaky logic going on in there.

[JakeChampion]

This was fixed in https://github.com/github/fetch/releases/tag/v3.6.2

[saifalislam]

What are this things ??