Type completions in jsDoc @augments and @implements tags.

[dragomirtitian]

Suggestion

Add code completions in jsDoc @augments and @implements clauses.

Use Cases

Anybody using the new @implements and @augments jsDoc tags will benefit from this.

Examples

Inside the {} triggering code completions should show types.

/**
 * @augments {}
 * @implements {}
 */
declare class B {
 b(): void;
 i(): void;
}

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

This is a flow-on from #36292 cc: Nathan Shively-Sanders (@sandersn)

[dragomirtitian]

I have a PR ready to go for this once the @implements (#36292) PR makes it in.

[sandersn]

It turns out that Typescript doesn't even support this properly — there aren't even any (good) completions in Typescript for class B implements /**/. And it's not a completion location at all, so you have to request completions manually in the first place.

We can wait to fix this issue until completions for Typescript interfaces is available, at which point it should be fairly simple.