TypeScript type safety patterns and best practices for maximum type coverage. Use when reviewing TypeScript code for type issues, eliminating `any` types, or when user mentions type safety, 型安全, 型カバレッジ, strict mode.
View on GitHubthkt/claude-config
development-skills
January 22, 2026
Select agents to install to:
npx add-skill https://github.com/thkt/claude-config/blob/main/skills/reviewing-type-safety/SKILL.md -a claude-code --skill reviewing-type-safetyInstallation paths:
.claude/skills/reviewing-type-safety/# Type Safety Review ## Detection | ID | Pattern | Fix | | --- | ----------------------------- | ----------------------------- | | TS1 | `any` | `unknown` + type guard | | TS1 | Implicit any | Explicit type annotation | | TS2 | `value as Type` | Type guard function | | TS2 | `value!` (non-null assertion) | Explicit null check | | TS3 | `function fn(data)` (untyped) | `function fn(data: Type)` | | TS3 | Missing return type | Explicit `: ReturnType` | | TS4 | `default:` without exhaustive | `default: assertNever(value)` | ## Criteria Type coverage >= 95%. Any usage = 0. Strict mode all enabled. ## References | Topic | File | | -------- | ----------------------------- | | Coverage | `references/type-coverage.md` | | Guards | `references/type-guards.md` | | Strict | `references/strict-mode.md` | | Result | `references/result-type.md` |