typescript-pro

Branded types use an intersection with a unique brand property, like `type Brand<T, B> = T & { readonly __brand: B }`. This creates nominal typing so a UserId string cannot be accidentally passed where an OrderId is expected, catching mix-ups at compile time.

Define a union where each member shares a literal tag field, such as `status: 'loading' | 'success' | 'error'`. Switch on the tag to narrow types automatically, and use a `never` assertion in the default case to enforce exhaustive handling.

Enable `strict: true` plus `noUncheckedIndexedAccess`, `noImplicitOverride`, and `exactOptionalPropertyTypes` for maximum safety. Use `module: NodeNext` for Node.js projects or `moduleResolution: bundler` for Vite and Next.js setups.

Yes, project references with `composite: true` enable incremental compilation across packages, so only changed projects rebuild. Define references in a root tsconfig and set `incremental: true` with a tsBuildInfoFile for faster subsequent builds.

Avoid `as` assertions when a type guard or `satisfies` operator can validate the value instead, since assertions bypass compiler checks. Reserve them for branded type constructors and cases where the compiler cannot infer narrowing.