[Cheng (chengchuu)]

Summary

Fixes #64862

Avoid repeatedly building later references when a clean, loaded project already contains the opened file. Earlier candidates still run in parallel, preserving reference order and breadth-first selection.

Remove later candidates after traversal, with a fast path in OrderedMap to keep pruning linear. Initial searches can still build unrelated projects; source or configuration changes invalidate the shortcut.

Reproduction

The standalone reproduction opens and closes three files belonging to tsconfig.app.json. Before the fix, the language server built and deleted the unrelated tsconfig.node.json project three times; afterward, it did so only once during initial discovery. All three textDocument/documentSymbol requests succeeded.

Validation

All checks below passed on macOS ARM64, run from the repository root.

go -C tsc test -mod=readonly \
  ./internal/core ./internal/project/... ./internal/lsp/... \
  ./internal/ls/... ./internal/api/... ./cmd/tsc
go -C tsc test -mod=readonly -race \
  ./internal/collections ./internal/core ./internal/project/... ./internal/lsp/...
go -C tsc test -mod=readonly -race ./internal/project \
  -run '^TestProjectCollectionBuilder' -count=10
npx hereby test
npx hereby lint
npx hereby check:format

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[Cheng (chengchuu)]

@microsoft-github-policy-service agree

[Copilot]

🟢 Approval recommended

No unresolved blocking issues were identified, and the reviewed changes include regression coverage for the affected behavior.

No open issues 🎉

_{Review effort: Lite}