typescript-migration-guide

Gradual JavaScript to TypeScript migration uses a three-stage strategy: enable allowJs, keep checkJs false, and progressively add types. This lets existing JS code run under TS with minimal changes while enforcing behavior validation in stages.

Configuring tsconfig for Vue 3 and Express uses a layered approach: a base config plus dedicated node and app configs. This provides practical isolation for frontend, backend, and Node tooling during TypeScript migration.

Yes, you can add type safety to JavaScript files without converting them by using JSDoc-based typing and transitional patterns. This intermediate approach applies type checks to modules that cannot be converted immediately.

Yes, TypeScript migration supports CI checks to maintain stability. The progressive plan enforces stability by integrating tooling, layered configuration, and continuous integration checks to validate behavior across each adoption stage.

A phased adoption strategy reduces downtime by sequencing changes and validating behavior in stages. This progressive approach lets existing JavaScript run under TypeScript with minimal changes while maintaining overall project stability.