Prevent deadlock in getCompletionsAtPosition(..., { includeSymbol: true }) API

[auvred]

Fixes #64166

The solution is to remove the program.GetTypeChecker(ctx) call from getExistingImports() and pass the checker explicitly instead.

[Copilot]

🟢 Approval recommended

The checker lifetime is consistently propagated, and the regression test covers the deadlocking completion path.

Pull request overview

Prevents API completion deadlocks by reusing the caller’s acquired type checker throughout auto-import processing.

Changes:

• Pass the active checker into auto-import views and fix generation.
• Remove nested checker acquisition from existing-import lookup.
• Add a regression test for includeSymbol: true.

File summaries

File	Description
tsc/internal/ls/languageservice.go	Passes checkers into auto-import views.
tsc/internal/ls/completions.go	Reuses completion checkers for auto-imports.
tsc/internal/ls/codeactions_importfixes.go	Threads one checker through import fixes.
tsc/internal/ls/codeactions_fixclassincorrectlyimplementsinterface.go	Supplies the existing checker to the view.
tsc/internal/ls/autoimport/view.go	Stores the caller-provided checker.
tsc/internal/ls/autoimport/import_adder.go	Uses the checker-backed view API.
tsc/internal/ls/autoimport/fix.go	Eliminates nested checker acquisition.
tsc/internal/api/session.go	Supplies the API checker when constructing a view.
tsc/internal/api/session_completion_test.go	Tests the reported deadlock scenario.

Review details

• Files reviewed: 9/9 changed files
• Comments generated: 0
• Review effort level: Balanced

---

💡 Add a code-review agent skill for context-aware, tailored reviews. Learn more in the docs.