[typescript-language-features] Add importModuleSpecifierEnding preference

[andrewbranch]

This PR fixes microsoft/TypeScript#24779
TS protocol update: microsoft/TypeScript#36725

[mjbvz]

Thanks! Quick question: does this only work on TS 3.8+ or does it work on older TS versions? Any idea which TS version it was first introduced with?

[andrewbranch]

It looks like it should work from TS 3.1 onward: microsoft/TypeScript#26028

[minestarks]

Does this also influence the "auto update import on rename file" scenario? Should it? (And should the user setting text reflect that?)

[andrewbranch]

@minestarks I’m open to suggestions on the text, but more and more refactors are incorporating auto-imports (microsoft/TypeScript#36615), so I don’t think we can call them all out individually.

Updating this PR with a default “auto” mode that omits this setting so TS Server can continue to pick a default based on project settings.

[minestarks]

@andrewbranch oh OK, I think the text is fine then, I was under the impression that "auto import" only referred to the completion list feature. But it may make sense to think of it as "any instance where we add/edit an import statement for you".

[andrewbranch]

I want to discuss how this setting will interact with future ESM work with the team first, so I’m going to close in the meantime.

[andrewbranch]

Ok, we decided to move forward with this, since we anticipate some time and complexity before we have a new module resolution mode that would require .js extensions. Build should turn green when microsoft/TypeScript#36725 is merged.

[mjbvz]

@andrewbranch Is this good to merge now?

[andrewbranch]

@mjbvz I don’t know how you all usually handle protocol updates—these changes should now build against TypeScript master/nightly, but will fail with type errors against TypeScript 3.8. Let me know if you want me to work around that somehow, but otherwise yes, this is ready to be merged.

[mjbvz]

Thanks. We are in endgame I'm going to hold off on merging this until the March release of VS Code

[mjbvz]

Thanks! Will be in VS Code 1.44 (and the insiders for it)