Added check to support Uint8Array in response sending

[alexandercerutti]

In an attempt to convert Buffer to Uint8Array in my codebase, I found out that sending an Uint8Array to .send(), makes it send as a JSON (which is wrong).

This was also noted in a comment in #4807 and I didn't find any issue in the repo (except that answer) or in the documentation about the lack of support to Uint8Array.

So I decided to look and test for a solution.

It seems to be enough to call ArrayBuffer.isView() when the kind of chunk is checked.
Even if ArrayBuffer.isView(chunk) returns true when chunk is a Buffer, I kept the Buffer.isBuffer(chunk) check, because of support to 0.10 (ArrayBuffer.isView() seems got introduced in Node v4.0.0, according to MDN).

Let me know if you see anything I can improve.

[wesleytodd]

From that thread, just in case anyone else comes here and is wondering what folks can do in the mean time:

Current workaround is to do Buffer.from(uint8ArrayData) before passing to send method.

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because of support to 0.10

We dont support that anymore, so see the one suggestion. 🎉

[alexandercerutti]

@wesleytodd okay great! I referred to the compatibility table in the website, but I understood that only v5 was not supporting it anymore. If v4 is not updated anymore (but security fixes and maintenance), this is fine. I've committed the suggested changes.

[wesleytodd]

v4 is still supported, and we can back port this if you would like to open a PR against the 4.x branch. It was just that this PR is opened against the main line, which is now v5. If you do that, the original change should be good.

[alexandercerutti]

I can that, sure! v4 is still widely used so I think it should receive such support.

Thanks for the guidance

[wesleytodd]

Sorry I should have said this in my previous review, but I would love to see a new test for this behavior before we merge. We should ideally use the same test here and in the backport.

[alexandercerutti]

I can try to do that in the next days (within the week). If I don't write here anymore, please ping me! 🙌 I have quite busy days upcoming...

[alexandercerutti]

@wesleytodd I found a free moment. I created a test with Uint8Array encoding. Let me know if this works for you or if you had in mind any other ideas to test.

[mysuf]

Allow me to join your discussion. I only encountered UInt8Array issue when migrating from v4 to v5, so the previous version was sending it probably correctly. So before you jump into anything, I would double check.

[alexandercerutti]

@mysuf thanks for joining. This fix actually started from the last version of v4, as I started debugging express as a dependency. Then, I compared the current code in master and I saw no differences. So I wonder how was it actually working for you...

[mysuf]

@alexandercerutti Looking at the v4 codebase and you are absolutely right. I have no clue how it could work, but I swear it did. Anyway thank you for this PR.