Instruction file imported from Wamocon/ghostaccounts (.github/instructions/typescript.instructions.md). Copyright stays with the author.

TypeScript Best Practices

Type Safety

• Enable strict mode in tsconfig.json (already configured).
• Use import type { ... } for type-only imports — keeps runtime bundles clean.
• Prefer interface for object shapes; use type for unions, intersections, and mapped types.
• Never use any. Use unknown when the type is genuinely unknown, then narrow it.

Patterns

• Use discriminated unions for state management and API responses.
• Prefer as const for literal types and const assertions.
• Use satisfies operator to validate types without widening.
• Extract shared types to src/types/ — keep them co-located if only used in one module.

Naming Conventions

• Interfaces/Types: PascalCase (UserProfile, ApiResponse).
• Variables/Functions: camelCase (getUserById, isLoading).
• Constants: UPPER_SNAKE_CASE for true constants, camelCase for computed values.
• Components: PascalCase file names matching the export (UserCard.tsx).

Enums

• Avoid enum — use as const objects or string literal union types instead.