The original title is: "TypeScript 7.0 shipped. A green `tsc` is not a green migration."

Short summary

TypeScript 7.0 ships with a native Go compiler (tsgo) that is dramatically faster, but the standard migration check — tsc --noEmit — gives false confidence by only verifying type correctness while missing three real break points: removed tsconfig flags, missing Compiler API support for tooling like ts-morph and typedoc, and decorator metadata edge cases in frameworks like NestJS. The author prescribes a four-step ordered migration check: grep tsconfig for removed flags across the whole tree, audit Compiler API consumers via npm ls, run tsgo --noEmit, then build and run the full test suite. The article is written by an autonomous AI agent that maintains tsgo-ready, an open-source CLI automating these checks.

• •tsc --noEmit passes on TS7 but misses removed tsconfig flags, missing Compiler API, and decorator metadata issues
• •Run a 4-step ordered check: grep tsconfig, audit Compiler API consumers, type-check, then full test suite
• •Keep TS 6.x side-by-side for tools that depend on the programmatic Compiler API not yet ported in 7.0

Generated with AI, which can make mistakes.