[typescript-language-features] Add command and editor context menu contribution for Find Source Definition

[andrewbranch]

I was overconfident in my ability to figure out how to expose microsoft/TypeScript#48264 in VS Code 😅, calling on @mjbvz for help. I started copying some relevant stuff about commands and contexts from Find File References, but then I realized the UI behavior I want is identical to definitions/implementations, and I didn’t know how to reconcile those two things.

[mjbvz]

@andrewbranch Can you share the VS Code branch you've been using for testing?

[andrewbranch]

When I was developing microsoft/TypeScript#48264, I just tested with VS Code Insiders by temporarily replacing the implementation of Go To Definition with the implementation of Find Source Definition since the response shape was the same. Now that microsoft/TypeScript#48264 is merged, I don’t have a VS Code branch capable of testing it yet.

[mjbvz]

@andrewbranch Thanks! Just pushed a fix that should enable this command in two places:

• Right click in the editor context menu
• Through the command palette

Notes for testers:

• Verify that the command only shows up when using TS 4.7+
• The command should jump to the definition directly if there is a single source definition. Otherwise it should show a list of references
• If no references are found, we show an error notification. This UX is not ideal. In the future we hope to show an inline notification like find all references does

[andrewbranch]

Thank you @mjbvz! 🌟

[IllusionMH]

Worked well so far for my "weird" cases:

1. JS project that has separate types folder with declare module 'path/to/js/file' {...} for key files. Correctly navigated to actual JS file (even for exports that are (intentionally) not exported in type declarations).
2. JS project where jsconfig.json and node_modules are in one folder, however node_modules with corresponding @types packages are couple of levels above. Navigated to correct JS source in node_modules.

[andrewbranch]

Thanks for testing!

[alexr00]

Works great, very useful!