TypeScript Best Practices

Non-Negotiables

• Strict mode is on — never weaken tsconfig.json (no "strict": false, no loosening noImplicitAny)
• Never use any — use unknown and narrow it, or find the actual type
• No @ts-ignore — use @ts-expect-error with a comment justifying why, if truly unavoidable
• No Function, Object, or {} as types — use specific signatures/interfaces

// BAD
function run(fn: Function) { fn() }
const data: Object = {}

// GOOD
function run(fn: () => void) { fn() }
const data: Record<string, unknown> = {}