test: add proxy tests

[bartlomieju]

Closes #2873

• http
  • fetch
  • module fetching
• update manual.html

EDIT:
I removed todo to test https proxy as we don't support https very well in deno_std server.
Eg, for example proxying request to `https://deno.land/welcome.ts:

deno_dev -A cli/tests/045_proxy_test.ts
Proxy server listening on http://127.0.0.1:4500/
CONNECT deno.land:443 HTTP/1.1
Proxy request to: deno.land:443
url deno.land:443
url_ deno.land:443 deno.land
error: Uncaught HttpOther: deno.land:443: URL scheme is not allowed
► file:///Users/biwanczuk/dev/deno/js/dispatch_json.ts:40:11
    at DenoError (file:///Users/biwanczuk/dev/deno/js/errors.ts:20:5)
    at unwrapResponse (file:///Users/biwanczuk/dev/deno/js/dispatch_json.ts:40:11)
    at sendAsync (file:///Users/biwanczuk/dev/deno/js/dispatch_json.ts:85:10)

We should be proxying to https://deno.land/welcome.ts but we receive deno.land:443 url in ServerRequest. Correct me if I'm wrong and it can be somehow done

[bartlomieju]

For convenience we should also support NO_PROXY env variable, which is sadly not supported by reqwest 😢

[bartlomieju]

🎉

CC @ry

[ry]

Nice work! It's great to have this nailed down.

At the end of the CLI help text, there are some env vars listed, can you add HTTP_PROXY there:

> deno --help
[ ... ]
ENVIRONMENT VARIABLES:
    DENO_DIR        Set deno's base directory
    NO_COLOR        Set to disable color

[bartlomieju]

Nice work! It's great to have this nailed down.

At the end of the CLI help text, there are some env vars listed, can you add HTTP_PROXY there:

> deno --help
[ ... ]
ENVIRONMENT VARIABLES:
    DENO_DIR        Set deno's base directory
    NO_COLOR        Set to disable color

Oh yes, forgot about that. I'll update the PR shortly

[bartlomieju]

@ry this should be ready now. Unfortunately tests fail on Windows if I use 0.0.0.0 addr

[ry]

LGTM!