typescript-best-practices

Modern TypeScript 5.x patterns your AI agent should use. Strict mode, discriminated unions,
satisfies operator, const assertions, branded types, NoInfer, using, and type-safe patterns.
> AI coding assistants default to any, skip strict mode, use as instead of satisfies, and
> model states with optional fields instead of discriminated unions. This plugin enforces the
> patterns that make TypeScript worth using.
Install
Cursor / Claude Code / Windsurf
Or copy skills/ into your .cursor/skills/ or .claude/skills/ directory.
What's Included
| Type | Name | Description |
| ------- | --------------------------- | ------------------------------------------------------------------------------------------- |
| Skill | typescript-best-practices | 13 rules for strict mode, satisfies, discriminated unions, branded types, NoInfer, and more |
| Rule | best-practices | Always-on behavioral rule that enforces current TypeScript patterns |
| Command | /audit | Scan your codebase for TypeScript anti-patterns |
What Agents Get Wrong
| What the agent writes | What you should use |
| ------------------------------------ | ---------------------------------------------------- |
| any for uncertain types | unknown with type narrowing |
| as SomeType to silence errors | satisfies SomeType for validation without widening |
| { success?: Data; error?: string } | Discriminated union with type field |
| strict: false in tsconfig | strict: true with proper null handling |
| import { SomeType } | import type { SomeType } for type-only imports |
| TypeVar + Generic[T] patterns | NoInfer , const assertions, branded types |
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