reimplement deno.enablePatterns feature

[turadg]

Attempting to add #92 after it was removed from master.

However, in my testing it's not working as expected. Even documents that don't match are getting Deno errors when enabled is true. For example,

@Flaque did #92 have this problem?

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This change is 

[Flaque]

@turadg haven't seen it before

[lucacasonato]

@turadg Some more config checks are happening in https://github.com/denoland/vscode_deno/blob/master/typescript-deno-plugin/src/plugin.ts

[turadg]

Thanks @lucacasonato . From a quick glance it looks like it'll be tricky to re-use this logic in the plugins module. Plus this method is doing a lot of unnecessary calculation repeatedly.

Taking a step back, should "being enabled" be a concern of the extension itself? I think the problem is that Deno is a special flavor of Typescript (e.g. assuming Deno is defined) but this extension is using the plain 'typescript' language ID. React adds similar assumptions to Javascript and the way it's handled in VS Code is with a new typescriptreact language ID. WDYT of making vscode_deno work the same way?

Then defining the files for which it's enabled is handled by VS Code settings. E.g. to enable everywhere,

"files.associations": {
    "*.ts": "typecriptdeno"
}

or to co-exist with other TS files,

"files.associations": {
    "*.deno.ts": "typecriptdeno"
}

[lucacasonato]

I don't think we should add our own language ID. We don't change the syntax at all (typescriptreact does because of JSX). We only change semantics.

[turadg]

We don't change the syntax at all

Deno has its own standard formatting which is different from other TypeScript formatters like Prettier.

We only change semantics.

What's a better way to determine whether a file is a Deno .ts file or a non-Deno .ts file?

I don't think we should add our own language ID.

What are the downsides of adding a language ID? I believe it could inherit from typescript such that it wouldn't diverge except for the specific parts necessary.

[lucacasonato]

@axetroy what do you think?

[axetroy]

@axetroy what do you think?

I didn't try this before.

Add a new file type association typescriptdeno. I don't know if it will affect the original typescript function.

[lucacasonato]

Thanks for the PR, but we are doing a full extension rewrite so this will not be landed anymore.