# Typescript Best Practices

> Write idiomatic TypeScript patterns for clean, maintainable code. Use when writing or refactoring TypeScript classes, functions, modules, or async logic.

- **Type:** Skill
- **Install:** `agentstack add skill-hoangnguyen0403-agent-skills-standard-typescript-best-practices`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [HoangNguyen0403](https://agentstack.voostack.com/s/hoangnguyen0403)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** Apache-2.0
- **Upstream author:** [HoangNguyen0403](https://github.com/HoangNguyen0403)
- **Source:** https://github.com/HoangNguyen0403/agent-skills-standard/tree/develop/.agents/skills/typescript/typescript-best-practices
- **Website:** https://www.npmjs.com/package/agent-skills-standard

## Install

```sh
agentstack add skill-hoangnguyen0403-agent-skills-standard-typescript-best-practices
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# TypeScript Best Practices

## **Priority: P1 (OPERATIONAL)**

## Implementation Guidelines

- **Naming**: Use **`PascalCase`** for Classes/Types/Interfaces, **`camelCase`** for variables/functions, and **`UPPER_SNAKE`** for static constants.
- **Functions**: Use **`arrow functions`** for callbacks/logic; **`function declaration`** for top-level exports. Always type **`public API`** returns.
- **Modules**: Use **`Named exports`** ONLY to enable better refactoring/auto-imports.
- **Async**: Use **`async/await`** with **`Promise.all()`** for parallel execution. Implement **`try-catch`** for error handling; type **`catch(e) as unknown`** and narrow before use. Avoid **`.then().catch()`** chains.
- **Classes**: Explicitly use **`private`**, **`protected`**, and **`public`** modifiers. Favor **`composition`** over inheritance and **`dependency injection`** with **`constructor injection`** and interfaces over singletons for testability.
- **Type Safety**: Use **`never`** for exhaustiveness checks in switch-cases.
- **Optional**: Use **`optional chaining`** (`?.`) and **`nullish coalescing`** (`??`) over manual checks.
- **Imports**: Enforce **`external packages → internal modules → relative imports`** order automatically via **`eslint-plugin-import`**. Use **`import type`** for interfaces/types to ensure better tree-shaking and zero runtime overhead.
- **Validation**: Use **`Zod`** or **`Tsoa`** for runtime boundary validation.

## Anti-Patterns

- **No Default Exports**: Use named exports.
- **No Implicit Returns**: Specify return types.
- **No Unused Variables**: Enable `noUnusedLocals`.
- **No `require`**: Use ES6 `import`.
- **No Empty Interfaces**: Use `type` or non-empty interface.
- **No `any`**: Use `unknown` or specific type.
- **No Unsafe Mocks**: Cast with `jest.Mocked` or `as unknown as T`.
- **No eslint-disable**: Fix root cause; never suppress warnings.

## References

See [references/examples.md](references/examples.md) for Immutable Interfaces, Exhaustiveness Checking, Assertion Functions, DI Patterns, and Import Organization.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [HoangNguyen0403](https://github.com/HoangNguyen0403)
- **Source:** [HoangNguyen0403/agent-skills-standard](https://github.com/HoangNguyen0403/agent-skills-standard)
- **License:** Apache-2.0
- **Homepage:** https://www.npmjs.com/package/agent-skills-standard

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-hoangnguyen0403-agent-skills-standard-typescript-best-practices
- Seller: https://agentstack.voostack.com/s/hoangnguyen0403
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.