TypeScript Strictest Standards

TypeScript 5.x · Strictest typing · No any/object · Generics required

• •Enable ALL strict flags: strict, noUncheckedIndexedAccess, exactOptionalPropertyTypes
• •Ban any and object types; use unknown with guards
• •Generics with constraints, satisfies operator, const assertions
• •Tests: .spec.ts next to source files; vitest, 80%+ coverage
• •Functional: pure functions, map/filter/reduce, immutability, readonly
• •Biome for linting/formatting; pnpm ≥10.17, pnpm-lock.yaml committed
• •React: function components, custom hooks, proper prop typing
• •Never: any/object types, non-null assertions !, || for defaults