TypeScript Coding Guidelines

The goal of these guidelines is to make TypeScript's type system do real work: catching bugs before runtime, making contracts explicit, and eliminating the "it works if you pass the right thing" class of errors. Follow them automatically whenever working in TypeScript — don't wait for the user to ask.

Linting — biome

Biome enforces the mechanical rules — noExplicitAny, noNonNullAssertion, noConsole, noForEach, useImportType, useConsistentTypeDefinitions, useConsistentArrayType, floating/misused promises, unused code — and handles formatting and import sorting. Don't restate them in review; run bun run lint (biome check) and fix what it reports rather than adding biome-ignore. The rule set lives in prek's biome.json.

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