Add fs read permission (don't squash)

[dsseng]

Fixes #1225;

• Add tests
  /cc @ry

[dsseng]

@ry please don't squash, @fewf should be credited for his work!

[ry]

We're getting this error in CI:

$ ./tools/test_format.py
/Users/travis/build/denoland/deno/target/release/deno --allow-read --allow-run tools/format.ts
Cannot resolve module "--allow-read --allow-run" from "."

[dsseng]

@ry fixed

[fewf]

I have a fix for what @J2P caught in a PR into this branch dsseng#2 .

I think it could be misleading that after giving permission to a prompt that says Deno requests read access to {filename}. Grant?, I've now given permission to the script to read all of my filesystem. (This applies to the write permission prompt too). To resolve this, granting permission through the prompt could give a one-time permission to the script, or the prompt could read something like "Deno requests read access to your filesystem. Grant?"

[ry]

To resolve this, granting permission through the prompt could give a one-time permission to the script, or the prompt could read something like "Deno requests read access to your filesystem. Grant?"

I agree - but let's fix that in a separate PR - because the same applies to allow-write too

[ry]

@fewf I've pushed your patch

[ry]

Hoping to land this one tomorrow - but it needs a few more fixes to go green.

[ry]

LGTM - very nice work @sh7dm and @fewf !

I'm sure this is going to break a lot of code - but it's better to do this now than 6 months from now.