Changelog

microsoft/typescript-go · Jun 8–14, 2026 · 41 commits

TypeScript-Go adds completion APIs, watcher backend, and Unicode fixes

A big week of API growth, stronger declaration emit, better file watching, and multiple parser/checker crash fixes.

Major API expansion for editors and tooling

New native-preview language service endpoints — Added find references, signature usage, and completions APIs, along with the supporting client types and symbol-handle plumbing. This is the week’s biggest surface-area expansion and makes the preview compiler much more useful for editor integrations.

Diagnostics now return UTF-16 positions — Diagnostic locations are now converted to editor-friendly UTF-16 offsets before being returned, fixing misreported spans around Unicode text.

Reliability and correctness fixes across parser, checker, and config loading

Unicode semantics now match JavaScript more closely — The scanner and checker switched to JS-compatible casing and identifier tables, fixing non-ASCII identifier classification, intrinsic string mappings, and surrogate-pair behavior.

Several crashers and recursion bugs were fixed — Addressed panics and stack overflows in rename across solution configs, extends: null, invalid JSDoc names, recursive type resolution, TypeToString, and speculative parse-cache updates.

tsconfig validation is stricter and clearer — Missing entries under files are now reported, inherited config parse errors surface properly, and malformed extends chains no longer fail silently.

Declaration emit got a broad cleanup pass

More complete .d.ts output — Declaration emit now preserves more JSDoc text, dedupes CommonJS export assignments, follows triple-slash references across referenced projects, and handles additional expando/class-property cases correctly.

Better diagnostics during emit — New declaration paths now set up symbol-accessibility diagnostics for additional JS patterns like object.defineProperty and expando assignments.

Watch mode and language service performance improved

New watcher backend powers LSP and CLI watch mode — The server can use native recursive watchers on Windows and macOS, and CLI watch mode was rebuilt on the new fswatch layer with proper cancellation support.

Checker and scanner hot paths were optimized — Scanner ASCII fast paths and tighter token scanning improve common-case performance, while checker allocations are deferred and idle language-service checkers now time out when unused.

Other misc changes

  • API enum emission switched away from const enum for the native preview package
  • Added Program.GetCheckerPool() and IndexInfo.declaration to the public API
  • Auto-imports no longer suggest non-identifiers
  • LSP initializationOptions now accepts null
  • Various CI, workflow, baseline, and test updates