feat: add rawHeaders to IncomingMessage

[MRayermannMSFT]

Description of Change

The goal of this change is to add a rawHeaders to IncomingMessage, similar to how Node's http.IncomingMessage has a rawHeaders. Related to #31531. (Note: link to Node docs may not scroll to the right spot)

I am initially opening this PR as a draft in order to get review and approval.

cc @electron/wg-api

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• tests are changed or added
• relevant documentation is changed or added
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: Added rawHeaders to IncomingMessage.

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[MRayermannMSFT]

@ckerr , FYI, I attempted to tag @electron/wg-api as suggested but I think I'm not able to do so since I'm not on the electron team. Feel free to edit my description with a working tag, or just as a comment. Thanks!

[MRayermannMSFT]

@codebytere @ckerr I'm digging into the implementation for this and I think I'm at a crossroads for how to go about this. I'd like to solicit y'all's feedback before choosing an option.

It looks like the headers are getting lowercased on the C++ side of things:

Which means that the "rawHeaders" being sent in SimpleURLLoaderWrapper::OnResponseStarted and received in net.ts aren't really the raw headers. So I think there's two options here:

1. Keep doing the lowercasing in C++, have SimpleURLLoaderWrapper::OnResponseStarted send those as "headers", and send actual raw headers in "rawHeaders".
2. Stop doing lowercasing in C++, have SimpleURLLoaderWrapper::OnResponseStarted send actual raw headers in "rawHeaders", and do lowercasing in net.ts.

Personally I'm partial to option 2 since net.ts/IncomingMessage is already doing some processing of what it thinks are the raw headers. Option 1 would also result in the size of the "response-started" event increasing by what would be basically duplicate data. But perhaps there's a good reason the lowercasing is being in C++? Let me know what y'all think.

[MRayermannMSFT]

Turns out net_converter.cc is not where the lowercasing is being done. I'll share more about what I found once I have pushed some changes. Also, I am going to go with option 2.

[MRayermannMSFT]

So turns out the lowercasing was being done in electron_api_url_loader.cc. The converter in net_converter.cc seems to potentially be dead code, but I don't know enough to say for sure.

[MRayermannMSFT]

I think this is now ready for review? Only thing left it seems is to update typings for IncomingMessage which I'm not 100% sure on how to do. Am willing to do it of course assuming instructions can be shared. Thanks!

[MRayermannMSFT]

@codebytere @ckerr any tips on how to get the electron.d.ts updated so my CI/CD builds can pass?

[zcbenz]

Just a notice that this organization won't have much activity this month, so review might have to wait until next month.

[MRayermannMSFT]

@zcbenz thanks for letting me know. Happy holidays to you and all the other maintainers!

[jkleinsc]

@MRayermannMSFT the typings get automatically generated from the documentation. I think the typing didn't get generated properly because the markdown needed an additional #.

[jkleinsc]

API LGTM

[nornagon]

API LGTM

[welcome]

Congrats on merging your first pull request! 🎉🎉🎉

[release-clerk]

Release Notes Persisted

Added rawHeaders to IncomingMessage.