Test Generation

Test Generation

Generate and maintain tests for the @dotcontext/cli project using Jest with ts-jest.

When to Use

• Writing tests for new services, generators, or utilities
• Adding test coverage for MCP gateway handlers
• Creating integration tests for CLI commands
• Validating bug fixes with regression tests
• During Execution (E) and Validation (V) phases

Test Configuration

• Framework: Jest with ts-jest preset
• Config: jest.config.js at project root
• Test location: Co-located with source files (*.test.ts) or in __tests__/ directories
• Test match patterns: **/__tests__/**/*.ts, **/?(*.)+(spec|test).ts
• Root: src/

# Run all tests
npm test

# Run specific test file
npx jest src/services/mcp/mcpServer.test.ts

# Run tests matching a pattern
npx jest --testPathPattern="mcp"

# Run with coverage
npx jest --coverage

Test Patterns by Layer

Service Tests

Services are the most common test target. Follow the pattern in current service and MCP tests:

import * as os from 'os';
import * as path from 'path';
import * as fs from 'fs-extra';
import { MyService } from './myService';
import type { CLIInterface } from '../../utils/cliUI';
import type { TranslateFn } from '../../utils/i18n';

// Create temp directory for isolation
let tempDir: string;

beforeEach(async () => {
  tempDir = await fs.mkdtemp(path.join(os.tmpdir(), 'test-'));
});

afterEach(async () => {
  await fs.remove(tempDir);
});

// Mock CLI interface
function createMockUI(): CLIInterface {
  return {
    displayWelcome: jest.fn(),
    displayProjectInfo: jest.fn(),
    displayStep: jest.fn(),
    displaySuccess: jest.fn(),
    displayWarning: jest.fn(),
    displayError: jest.fn(),
    // ... other CLIInterface methods
  };
}

// Mock translate function
const mockT: TranslateFn = ((key: string) => key) as TranslateFn;

Key patterns:

• Temp directories: Always use fs.mkdtemp() and clean up in afterEach
• Mock CLIInterface: Provide a mock with jest.fn() for each method
• Mock TranslateFn: Simple passthrough (key) => key
• Mock tool or gateway boundaries: Use jest.mock() at module level for filesystem, prompt loaders, or MCP helpers