TypeScript Code Style Guide

Types and Type Safety

• Avoid explicit type annotations when TypeScript can infer
• Avoid implicitly any; explicitly type when necessary
• Use accurate types: prefer Record<PropertyKey, unknown> over object or any
• Prefer interface for object shapes (e.g., React props); use type for unions/intersections
• Prefer as const satisfies XyzInterface over plain as const
• Prefer @ts-expect-error over @ts-ignore over as any
• Avoid meaningless null/undefined parameters; design strict function contracts
• Prefer ES module augmentation (declare module '...') over namespace; do not introduce namespace-based extension patterns
• When a type needs extensibility, expose a small mergeable interface at the source type and let each feature/plugin augment it locally instead of centralizing all extension fields in one registry file
• For package-local extensibility patterns like PipelineContext.metadata, define the metadata fields next to the processor/provider/plugin that reads or writes them

Async Patterns