TypeScript 7.0 RC
5 hours ago
- #typescript
- #performance
- #release
- TypeScript 7.0 Release Candidate (RC) is announced, built on a new Go-based foundation, offering up to 10x speed improvements over TypeScript 6.0.
- It can be installed via npm: `npm install -D typescript@rc`; editor support is available through the TypeScript Native Preview extension for VS Code.
- The new Go codebase maintains architectural parity with TypeScript 6.0, ensuring identical type-checking semantics and compatibility with existing test suites.
- It supports parallelization with configurable flags like `--checkers` and `--builders`, and includes a single-threaded mode via `--singleThreaded`.
- A rebuilt `--watch` mode uses a ported Parcel file-watcher for efficient cross-platform performance, reducing resource usage.
- TypeScript 7.0 adopts TypeScript 6.0's new defaults and deprecations, including changes to `rootDir`, `types`, and strict error handling for deprecated features.
- Template literal types now preserve Unicode code points, changing inference behavior for strings with surrogate pairs.
- JavaScript support has been reworked for consistency with TypeScript analysis, removing special treatment for certain JSDoc patterns and Closure syntax.
- The release includes side-by-side compatibility with TypeScript 6.0 using the `@typescript/typescript6` package and npm aliases to avoid conflicts.
- Nightly builds are available under `@typescript/native-preview`; stable releases will be published under the `typescript` package after final release.
- Feedback is encouraged from real projects via the issue tracker or social media, with a stable release planned within the next month.