Instruction file imported from juninmd/vibe-code (.github/instructions/typescript-standards.instructions.md). Copyright stays with the author.

Rule: TypeScript Standards

1. Type Safety

• No any: The use of any is strictly prohibited. Use unknown if the type is truly not known ahead of time, and use type guards to narrow it down.
• Explicit Returns: Always declare return types for functions and methods to prevent unintended return values.
• Strict Null Checks: Always handle null and undefined explicitly. Use optional chaining (?.) and nullish coalescing (??).

2. Type Declarations

• Interfaces over Types: Prefer interface for object shapes as they are more extensible. Use type for unions, intersections, and utility types.
• Enums: Avoid enum; prefer union types (e.g., type Status = 'open' | 'closed') or constant objects (as const).

3. General Practices

• Prefer readonly for properties that should not be mutated.
• Ensure all parameters in public APIs are typed.