Development Guide

Development practices for contributing to 2LY.

Code Style

TypeScript

• Use strict mode
• Explicit return types
• Prefer interfaces over types
• Use const for immutable values

Formatting

npm run lint
npm run format

Architecture Patterns

Service Pattern

Services handle business logic:

@injectable()
export class RuntimeService {
  async createRuntime(data: RuntimeInput): Promise<Runtime> {
    // Business logic here
  }
}

Repository Pattern

Repositories handle data access:

@injectable()
export class RuntimeRepository {
  async findById(id: string): Promise<Runtime | null> {
    // Data access here
  }
}

Dependency Injection

Use Inversify for DI:

container.bind<RuntimeService>(TYPES.RuntimeService)
  .to(RuntimeService)
  .inSingletonScope();

Testing

Unit Tests

describe('RuntimeService', () => {
  it('should create runtime', async () => {
    // Test implementation
  });
});

Integration Tests

Test component integration, mock external services.

Running Tests

npm run test
npm run test:watch
npm run test:coverage

Adding Features

1. Plan

• Create GitHub issue
• Discuss approach
• Get feedback

2. Implement

• Create feature branch
• Write tests first (TDD)
• Implement feature
• Update docs

3. Submit

• Create pull request
• Address review feedback
• Merge when approved

Common Tasks

Adding NATS Message

1. Create message class in packages/common/src/messages/
2. Implement serialize() and deserialize()
3. Register in message registry
4. Add handler in backend/runtime

Adding GraphQL Resolver

1. Update schema in packages/common/schema/apollo.schema.graphql
2. Generate types: npm run generate
3. Implement resolver in packages/backend/src/database/resolvers.ts
4. Add tests

Adding Frontend Component

1. Create in packages/frontend/src/components/
2. Use Tailwind for styling
3. Follow existing patterns
4. Add to Storybook if reusable

Best Practices

• Keep it simple: Solve the problem, nothing more
• Write tests: Test before implementation
• Document: Code comments and README updates
• Small PRs: Easier to review and merge
• Ask questions: Better to ask than assume

See Development Setup for environment details.