Add "enablePatterns" config option

[Flaque]

Overview

This PR adds a deno.enablePatterns config option that lets you specify particular paths or folders where the extension is enabled. This is useful for projects that contain both Node code and Deno code, such as the vscode_deno repo itself. This relates to #87

Example usage:

{
  "deno.enablePatterns": ["packages/deno/**", "*.deno.ts"]
}

Each item in the array matches a regex and only one item needs to match to enable the extension on that file.

Disclaimer

This is more of a suggestion. Totally understand if this is the wrong naming convention, or the wrong way to go about this.

Testing Done

I've played around with this in a number of different configurations in this example repo I setup. Though it might be a good idea for someone else to play around with it.

[jsejcksn]

Some questions to consider:

• Is the intended use for this to match patterns relative to the workspace directory or root directory?
• Regex patterns and/or glob patterns?
• Is deno.enablePatterns a more suitable name for an array of patterns? (ref. prior art: ESLint, Jest)

[Flaque]

@jsejcksn

Is the intended use for this to match patterns relative to the workspace directory or root directory?

Workspace directory, I'll add a note in the docs.

Regex patterns and/or glob patterns?

Regex, and same.

enablePatterns

Agreed, that's a better name, I'll update.

[David-Else]

@Flaque This looks amazing! I am trying to use Deno just for testing along with Snowpack for building. I need the test directory to be just for Deno test code with it's .ts extensions. The latest update on that seems to be microsoft/TypeScript#37582

Who has the authority to merge this, it has been nearly a month. Do you think it is ready now?

[bartlomieju]

LGTM, sorry it took so long @Flaque, thanks for this contribution.

[Flaque]

🎉🎉🎉🎉