[Bug] counter/index argument is not provided to callback functions

[julienroyer]

Describe the bug

For sync map/filter at least, only one argument is provided to the callback function (the current element).

The iterator helpers proposal specifies that the callback functions are provided two arguments: the current element and its counter/index.

To Reproduce

[...Iterator.from([0, 1]).filter((x, idx) => idx)]

Expected behavior

expected [1], got []

[MadProbe]

This has been fixed in version 3.0.0, and thank you for reporting this bug!
I still have in backlog making this polyfill more spec-compliant, and I have to carve out some time and will to make it as good as it can be.

[julienroyer]

Thanks a lot for fixing this bug!