typescript-best-practices

A Conductor skill providing guidance for writing type-safe, maintainable TypeScript code.

Overview

This skill activates when working with TypeScript files and provides guidance on:

• Type Safety: Interfaces, generics, discriminated unions, type guards
• Async Patterns: Promise handling, error management, parallel execution
• Null Handling: Optional chaining, nullish coalescing, strict null checks

Activation

The skill automatically activates when:

• Working with .ts or .tsx files
• Task description contains keywords: typescript, type, interface, generic, async
• Project tech stack includes TypeScript

Patterns Provided

| Pattern | Description | |---------|-------------| | type-safety | Type definitions, generics, discriminated unions | | async-patterns | Async/await, Promise handling, error management | | null-handling | Null safety, optional chaining, type guards |

Usage Examples

Type-Safe API Response

interface ApiResponse<T> {
  data: T;
  status: number;
  timestamp: string;
}

type ApiResult<T> =
  | { success: true; response: ApiResponse<T> }
  | { success: false; error: Error };

async function fetchApi<T>(url: string): Promise<ApiResult<T>> {
  try {
    const response = await fetch(url);
    const data = await response.json();
    return {
      success: true,
      response: { data, status: response.status, timestamp: new Date().toISOString() }
    };
  } catch (error) {
    return { success: false, error: error as Error };
  }
}

Generic Repository Pattern

interface Entity {
  id: string;
  createdAt: Date;
  updatedAt: Date;
}

interface Repository<T extends Entity> {
  findById(id: string): Promise<T | undefined>;
  findAll(): Promise<T[]>;
  create(data: Omit<T, 'id' | 'createdAt' | 'updatedAt'>): Promise<T>;
  update(id: string, data: Partial<T>): Promise<T>;
  delete(id: string): Promise<void>;
}

Configuration

Recommended tsconfig.json settings:

{
  "compilerOptions": {
    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "noImplicitReturns": true,
    "noFallthroughCasesInSwitch": true,
    "noUncheckedIndexedAccess": true,
    "exactOptionalPropertyTypes": true
  }
}

Related Skills

• testing-strategies: For TypeScript testing patterns
• api-design: For typed API development

Changelog

1.0.0

• Initial release
• Type safety patterns
• Async/await patterns
• Null handling patterns