Type definitions are not loaded immediately after tsserver startup when using `createAsyncLanguageServicePlugin`

[mizdra]

Summary

The behavior immediately after tsserver initialization is different between createAsyncLanguageServicePlugin and createLanguageServicePlugin.

In createLanguageServicePlugin, tsserver loads the type definitions of the files that Volar.js processes. However, createAsyncLanguageServicePlugin does not.

How to repdoduce

reproduction: mizdra/playground-volar-typescript-service-plugin@e73b0e1

1. Checkout mizdra/playground-volar-typescript-service-plugin@e73b0e1
2. Open workspace on VS Code
3. When the tsdk switching prompt appears, select "Allow".
4. Open example/index.ts in the tab
5. Restart tsserver

2024-12-08.18.38.50.mov

Expected behavior

tsserver loads the type definitions of ts-logo-256.png.

Actual behavior

tsserver does not load the type definitions of ts-logo-256.png. When import specifier is changed, the tsserver loads the type definition.

[mizdra]

Is this a bug? Or is this expected behavior? Are there any technical limitations with createAsyncLanguageServicePlugin?

[johnsoncodehk]

A quick look, createAsyncLanguageServicePlugin relies on using markAsDirty to refresh diagnostics after initialization, the problem may be that markAsDirty is no longer working now. (I haven't tried the repro case yet.)

volar.js/packages/typescript/lib/quickstart/createAsyncLanguageServicePlugin.ts

Line 107 in 3e996b3

info.project.markAsDirty();

[johnsoncodehk]

It seems to be caused by starting from a certain TS version, the module resolved cache of a file will only be updated when the file content is changed. (Still digging for a solution.)

[mizdra]

I confirmed that the problem has been fixed. Thank you!