Rely on proxy-agent for detecting environment variables

[0x2b3bfa0]

If no URI is provided, then proxy-from-env is used to get the URI from $HTTP_PROXY, $HTTPS_PROXY and $NO_PROXY among others. (Excerpt from proxy-agent documentation)

This pull request will fix #760 by honoring the no_proxy environment variable and add compatibility for proxy types other than https as listed on this table.

[0x2b3bfa0]

Note for testers (hello, testers): you can use mitmproxy to verify whether the no_proxy environment variable is being honored or not.

Spoiler: it works as expected.

[DavidGOrtega]

Note for testers (hello, testers): you can use mitmproxy to verify whether the no_proxy environment variable is being honored or not.

Can we include a test to nt have to test it manually?

[DavidGOrtega]

Note for testers (hello, testers): you can use mitmproxy to verify whether the no_proxy environment variable is being honored or not.

Can we include a test to nt have to test it manually?

[0x2b3bfa0]

Yes, we can, of course. If the official NO_PROXY tests aren't enough for you, we can replicate them, but there is probably no point in testing the functionality of all our dependencies. Speak about deffensive programming. 😄

[DavidGOrtega]

We have a simple integration test launching a proxy and passing through it already, it does not covers every proxy type on how the SCM responds to them, but at least is one. I was thinking that maybe we could avoid manual test.
I will trust your own test and the code changes.

[DavidGOrtega]

I missed an integration test but I guess we can assume it works
👍

[0x2b3bfa0]

Rest assured that it works, and that funcationality is already being tested by the official library.

If you want, I can add a test on our side, though. 🤷🏼‍♂️ We can add an invalid proxy, set NO_PROXY=example.com or similar, and make a request to example.com and other to example.org for... example.

Still, it would be slightly pointless; we already use http_proxy for all the test suite, and testing all the proxy features doesn't seem especially constructive.

cml/tests/setup.js

Line 3 in 4f7a5d9

process.env.http_proxy = `http://localhost:${PORT}`;