Code quality tools

In Node.js development, code quality tools are key to ensuring project maintainability and team collaboration efficiency. From static analysis to automated testing, these tools help developers quickly identify issues and standardize code style.

Static Code Analysis Tools

ESLint is one of the most popular JavaScript static analysis tools. By configuring rule sets, it can detect potential issues in code in real time:

// Example .eslintrc.js configuration
module.exports = {
  env: {
    node: true,
    es2021: true
  },
  extends: ['eslint:recommended', 'plugin:@typescript-eslint/recommended'],
  parser: '@typescript-eslint/parser',
  rules: {
    'no-console': 'warn',
    'semi': ['error', 'always'],
    'quotes': ['error', 'single']
  }
};

The TypeScript compiler itself also provides type-checking functionality:

// Strict mode configuration in tsconfig.json
{
  "compilerOptions": {
    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true
  }
}

Code Style Automation

Prettier can work with ESLint to automate code formatting:

// .prettierrc
{
  "printWidth": 100,
  "tabWidth": 2,
  "singleQuote": true,
  "trailingComma": "es5"
}

Husky combined with lint-staged can automatically trigger checks during Git commits:

// Package.json configuration snippet
{
  "husky": {
    "hooks": {
      "pre-commit": "lint-staged"
    }
  },
  "lint-staged": {
    "*.{js,ts}": ["eslint --fix", "prettier --write"]
  }
}

Test Coverage Tools

Jest combined with Istanbul can generate detailed test coverage reports:

// jest.config.js
module.exports = {
  collectCoverage: true,
  coverageThreshold: {
    global: {
      branches: 80,
      functions: 85,
      lines: 90,
      statements: 90
    }
  }
};

Example test case:

// utils.test.ts
import { formatDate } from './utils';

describe('Date formatting', () => {
  it('should correctly handle timestamp conversion', () => {
    expect(formatDate(1625097600000)).toBe('2021-06-30');
  });
});

Dependency Visualization

Use madge to generate module dependency graphs:

npx madge --image graph.svg src/index.ts

depcheck can detect unused dependencies:

{
  "scripts": {
    "check-deps": "depcheck"
  }
}

Security Vulnerability Scanning

npm audit is a built-in security check tool. Example CI integration:

# GitHub Actions configuration
name: Security Audit
on: [push]
jobs:
  audit:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - run: npm install
      - run: npm audit --audit-level=moderate

Performance Analysis Tools

Node.js's built-in profiler can generate flame graphs:

node --prof app.js
node --prof-process isolate-0xnnnnnnnnnnnn-v8.log > processed.txt

clinic.js provides a more intuitive diagnostic toolchain:

const clinic = require('clinic');

clinic.doctor({
  cmd: 'node server.js',
  detectPort: true
}, (err, result) => {
  console.log(result);
});

Documentation Generation Tools

TypeDoc can generate API documentation based on TS types:

/**
 * User service class
 * @remarks
 * Handles all user-related operations
 */
class UserService {
  /**
   * Create a new user
   * @param userInfo - User information object
   */
  create(userInfo: UserDTO) {
    // ...
  }
}

Continuous Integration Solutions

Complete CI configuration example:

name: Node.js CI
on: [push, pull_request]
jobs:
  build:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        node-version: [14.x, 16.x, 18.x]
    steps:
      - uses: actions/checkout@v3
      - uses: actions/setup-node@v3
        with:
          node-version: ${{ matrix.node-version }}
      - run: npm ci
      - run: npm run build
      - run: npm test
      - run: npm run lint
      - run: npm audit --audit-level=critical

Code Complexity Monitoring

Use plato to visualize code complexity:

const plato = require('plato');

plato.inspect(['src/**/*.js'], 'report', {
  title: 'Project Analysis',
  eslint: require('./.eslintrc')
}, report => {
  console.log('Analysis completed');
});

Type Definition Checking

For large TypeScript projects, type testing is important:

// test/types.test.ts
import assert from 'assert';
import { User } from '../src/models';

// Test type inference
const testUser: User = {
  id: 1,
  name: 'test'
};

assert.ok(testUser.name === 'test');

Code Duplication Detection

jscpd can detect duplicate code blocks:

{
  "jscpd": {
    "threshold": 5,
    "ignore": ["**/*.spec.ts"]
  }
}

Modern Toolchain Integration

Complete toolchain configuration example:

// package.json
{
  "scripts": {
    "prepare": "husky install",
    "lint": "eslint . --ext .ts,.js",
    "format": "prettier --write .",
    "test": "jest --coverage",
    "build": "tsc",
    "audit": "npm audit --audit-level=moderate",
    "check-types": "tsc --noEmit",
    "check-deps": "depcheck",
    "check": "run-s check-types lint test audit check-deps"
  }
}