TypeScript 6.0 Beta Released Ahead of Go Rewrite
Microsoft announced the beta release of TypeScript 6.0. This version is reportedly the last to be based on the current JavaScript codebase before a significant rewrite of the compiler in Go for version 7.0 and beyond. The shift is expected to impact React and Next.js developer workflows by enabling faster and more reliable builds.
- The rewrite, internally codenamed "Project Corsa," aims to solve performance bottlenecks in large codebases; benchmarks show it compiles Visual Studio Code's 1.5 million lines of code in ~8.7 seconds, a 10x improvement from the current 89 seconds. - Go was chosen over languages like Rust or C# because its structure is similar to the existing TypeScript codebase, allowing developers to "port" the compiler instead of rewriting it from scratch, which minimizes the risk of introducing new bugs. - The new Go-based compiler will be a standalone binary, which removes the dependency on a Node.js runtime for compilation. - TypeScript 6.0 serves as a "bridge" release to prepare for the transition, introducing a `--stableTypeOrdering` flag to help align code with the new compiler's behavior and deprecating older features like targeting `ES5`. - The performance improvements will also impact the IDE experience, with tests showing an 8x faster project load time in editors like VS Code and a reduction in memory usage by about half. - TypeScript 6.0 makes `strict: true` the new default setting and adds native types for upcoming ECMAScript features, including the Temporal API and `RegExp.escape`.
