TypeScript - Migrating from JavaScript

Gradual migration

• Start with // @ts-check in .js files and JSDoc types.
• Convert leaf modules to .ts first and enable strict progressively.
• Add any pragmatically with TODOs, replace with precise types over time.

JSDoc typing

/** @typedef {{ id: string; name: string }} User */

/** @param {User} u */
function hello(u) { return `Hi ${u.name}` }

tsconfig settings

• Use skipLibCheck to ease ecosystem issues.
• Consider noPropertyAccessFromIndexSignature and noUncheckedIndexedAccess later.