port Header class changes from core PR#38986

[Ethan-Arrowood]

This PR ports some of the changes I've made in nodejs/node#38986

Includes an argument length check as well that isn't in my core PR yet

[codecov-commenter]

Codecov Report

Merging #922 (083ad52) into main (34cb4c6) will decrease coverage by 1.17%.
The diff coverage is 37.23%.

@@            Coverage Diff             @@
##             main     #922      +/-   ##
==========================================
- Coverage   93.72%   92.55%   -1.18%     
==========================================
  Files          29       29              
  Lines        2517     2564      +47     
==========================================
+ Hits         2359     2373      +14     
- Misses        158      191      +33     

Impacted Files	Coverage Δ
lib/core/errors.js	87.50% <0.00%> (-12.50%)	⬇️
lib/api/headers.js	54.12% <42.68%> (-6.69%)	⬇️

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[mcollina]

lgtm but it makes me uncomfortable in keep landing changes without tests.

[ronag]

@mcollina It's only fetch related changes that we land without tests. I think this is good in order to keep velocity up and it adds a natural place for new contributors to help us. If you are still uncomfortable then I guess we can slow down a bit and focus on tests. I was hoping to try and implement functionality and then focus on tests before release.

[ronag]

@Ethan-Arrowood would be great if we could port over the tests from undici-fetch.

[mcollina]

@mcollina It's only fetch related changes that we land without tests. I think this is good in order to keep velocity up and it adds a natural place for new contributors to help us. If you are still uncomfortable then I guess we can slow down a bit and focus on tests. I was hoping to try and implement functionality and then focus on tests before release.

That'd be ok if it's a feature branch and not main. Anyway, let's see what the timeline is... we can always move this into a different branch.

[ronag]

That'd be ok if it's a feature branch and not main

Yes you are totally right. Apologies.