从零开始打造 RandBox：一个强大的 JavaScript 随机数据生成库（4/5）- 测试体系与质量保证

前言

在前三篇文章中，我们深入探讨了 RandBox 的规划、架构和功能实现。今天，我将分享如何为 RandBox 构建完善的测试体系，确保库的质量和可靠性。对于一个随机数据生成库而言，测试面临着独特的挑战：如何测试”随机”的结果？如何保证跨平台的一致性？这些问题都需要巧妙的解决方案。

测试策略设计

测试金字塔原则

RandBox 的测试体系遵循经典的测试金字塔原则：


        /\
       /  \
      / E2E \ (少量端到端测试)
     /______\
    /        \
   / 集成测试  \ (中等数量)
  /____________\
 /              \
/   单元测试      \ (大量基础测试)
/________________\

核心测试挑战

1. 随机性测试的悖论

随机数据生成的结果本质上是不可预测的，但测试需要可预测的断言。

解决方案：种子控制


// 使用固定种子确保测试结果可重现
const randBox = new RandBox('test-seed-123');
assert(randBox.integer(1, 10) === 7); // 在相同种子下总是返回7

2. 统计性质验证

需要验证生成数据的统计特性是否符合预期。

解决方案：大数定律


// 生成大量数据验证分布特性
test('integer distribution should be uniform', () => {
  const results = {};
  const iterations = 10000;
 
  for (let i = 0; i < iterations; i++) {
    const value = randBox.integer(1, 10);
    results[value] = (results[value] || 0) + 1;
  }
 
  // 验证每个数字出现频率接近期望值
  Object.values(results).forEach(count => {
    const expected = iterations / 10;
    const tolerance = expected * 0.1; // 10% 容差
    assert(Math.abs(count - expected) < tolerance);
  });
});

单元测试实现

1. 基础功能测试框架

选择 AVA 作为测试框架，原因如下：

简洁的 API 设计
内置并行执行
强大的断言库
优秀的错误报告


// test/basics.test.js
import test from 'ava';
import RandBox from '../src/index.js';
 
test.beforeEach(t => {
  // 每个测试使用相同的种子确保可重现性
  t.context.randBox = new RandBox('test-seed');
});
 
test('integer() should return number within range', t => {
  const { randBox } = t.context;
 
  for (let i = 0; i < 100; i++) {
    const result = randBox.integer(1, 10);
    t.true(Number.isInteger(result));
    t.true(result >= 1 && result <= 10);
  }
});
 
test('integer() with exclude option', t => {
  const { randBox } = t.context;
  const exclude = [5, 7, 9];
 
  for (let i = 0; i < 100; i++) {
    const result = randBox.integer({ min: 1, max: 10, exclude });
    t.false(exclude.includes(result));
  }
});

2. 参数验证测试


test('integer() parameter validation', t => {
  const { randBox } = t.context;
 
  // 测试无效参数
  t.throws(() => randBox.integer('invalid'), {
    instanceOf: TypeError,
    message: /Expected number/
  });
 
  // 测试范围错误
  t.throws(() => randBox.integer(10, 5), {
    instanceOf: RangeError,
    message: /Min cannot be greater than max/
  });
 
  // 测试边界值
  t.notThrows(() => randBox.integer(0, 0)); // 应该总是返回0
  t.is(randBox.integer(0, 0), 0);
});

3. 复杂功能测试


// 测试姓名生成
test('name() should generate valid names', t => {
  const { randBox } = t.context;
 
  // 中文姓名测试
  const chineseName = randBox.name({ nationality: 'zh' });
  t.true(typeof chineseName === 'string');
  t.true(chineseName.length >= 2 && chineseName.length <= 4);
 
  // 英文姓名测试
  const englishName = randBox.name({ nationality: 'en' });
  t.true(englishName.includes(' ')); // 英文名包含空格
 
  // 带前缀的姓名
  const nameWithPrefix = randBox.name({
    nationality: 'en',
    prefix: true,
    gender: 'male'
  });
  t.true(nameWithPrefix.startsWith('Mr.') || nameWithPrefix.startsWith('Dr.'));
});
 
// 测试邮箱生成
test('email() should generate valid email addresses', t => {
  const { randBox } = t.context;
 
  const email = randBox.email();
 
  // 基本格式验证
  t.regex(email, /^[^\s@]+@[^\s@]+\.[^\s@]+$/);
 
  // 自定义域名测试
  const customEmail = randBox.email({ domain: 'example.com' });
  t.true(customEmail.endsWith('@example.com'));
});

性能测试与基准测试

1. 性能测试框架搭建


// test/performance.test.js
import { performance } from 'perf_hooks';
import test from 'ava';
import RandBox from '../src/index.js';
 
function benchmark(name, fn, iterations = 10000) {
  const start = performance.now();
 
  for (let i = 0; i < iterations; i++) {
    fn();
  }
 
  const end = performance.now();
  const duration = end - start;
  const opsPerSec = (iterations / duration) * 1000;
 
  console.log(`${name}: ${duration.toFixed(2)}ms (${opsPerSec.toFixed(0)} ops/sec)`);
 
  return { duration, opsPerSec };
}
 
test('performance benchmarks', t => {
  const randBox = new RandBox();
 
  // 基础功能性能测试
  const integerPerf = benchmark('integer()', () => randBox.integer());
  const stringPerf = benchmark('string()', () => randBox.string());
  const namePerf = benchmark('name()', () => randBox.name());
 
  // 性能要求：每秒至少处理10000次操作
  t.true(integerPerf.opsPerSec > 10000);
  t.true(stringPerf.opsPerSec > 5000);
  t.true(namePerf.opsPerSec > 1000);
});

2. 内存使用测试


test('memory usage should be reasonable', t => {
  const initialMemory = process.memoryUsage().heapUsed;
 
  // 创建多个实例
  const instances = [];
  for (let i = 0; i < 1000; i++) {
    instances.push(new RandBox());
  }
 
  // 生成大量数据
  instances.forEach(randBox => {
    for (let j = 0; j < 100; j++) {
      randBox.name();
      randBox.email();
      randBox.address();
    }
  });
 
  const finalMemory = process.memoryUsage().heapUsed;
  const memoryIncrease = finalMemory - initialMemory;
 
  // 内存增长应该在合理范围内（小于50MB）
  t.true(memoryIncrease < 50 * 1024 * 1024);
});

统计特性验证

1. 随机分布测试


// test/statistics.test.js
import test from 'ava';
import RandBox from '../src/index.js';
 
function chiSquareTest(observed, expected, significance = 0.05) {
  let chiSquare = 0;
 
  for (let i = 0; i < observed.length; i++) {
    const diff = observed[i] - expected[i];
    chiSquare += (diff * diff) / expected[i];
  }
 
  // 简化的卡方检验（实际应用中需要查表）
  const degreesOfFreedom = observed.length - 1;
  const critical = degreesOfFreedom * 2; // 简化阈值
 
  return chiSquare < critical;
}
 
test('integer distribution should pass chi-square test', t => {
  const randBox = new RandBox();
  const buckets = new Array(10).fill(0);
  const iterations = 10000;
 
  for (let i = 0; i < iterations; i++) {
    const value = randBox.integer(0, 9);
    buckets[value]++;
  }
 
  const expected = new Array(10).fill(iterations / 10);
  const isUniform = chiSquareTest(buckets, expected);
 
  t.true(isUniform, 'Distribution should be approximately uniform');
});
 
test('floating point distribution', t => {
  const randBox = new RandBox();
  const samples = [];
 
  for (let i = 0; i < 1000; i++) {
    samples.push(randBox.floating(0, 1));
  }
 
  // 验证范围
  samples.forEach(sample => {
    t.true(sample >= 0 && sample <= 1);
  });
 
  // 验证均值接近0.5
  const mean = samples.reduce((sum, val) => sum + val, 0) / samples.length;
  t.true(Math.abs(mean - 0.5) < 0.05);
});

2. 正态分布测试


test('normal distribution should have correct properties', t => {
  const randBox = new RandBox();
  const samples = [];
  const mean = 100;
  const stdDev = 15;
 
  for (let i = 0; i < 1000; i++) {
    samples.push(randBox.normal(mean, stdDev));
  }
 
  // 计算样本均值和标准差
  const sampleMean = samples.reduce((sum, val) => sum + val, 0) / samples.length;
  const variance = samples.reduce((sum, val) => sum + Math.pow(val - sampleMean, 2), 0) / samples.length;
  const sampleStdDev = Math.sqrt(variance);
 
  // 验证均值和标准差在合理范围内
  t.true(Math.abs(sampleMean - mean) < 2);
  t.true(Math.abs(sampleStdDev - stdDev) < 2);
});

兼容性测试

1. 多环境测试


// test/compatibility.test.js
test('should work in different JavaScript environments', t => {
  // Node.js 环境测试
  if (typeof window === 'undefined') {
    t.true(true, 'Running in Node.js environment');
  }
 
  // 测试 ES6 模块导入
  t.truthy(RandBox);
  t.true(typeof RandBox === 'function');
 
  // 测试基本功能
  const randBox = new RandBox();
  t.true(typeof randBox.random === 'function');
});
 
// 浏览器环境测试（使用 Puppeteer）
test('browser compatibility', async t => {
  const puppeteer = require('puppeteer');
  const browser = await puppeteer.launch();
  const page = await browser.newPage();
 
  await page.addScriptTag({
    path: './dist/index.umd.js'
  });
 
  const result = await page.evaluate(() => {
    const randBox = new window.RandBox();
    return {
      integer: randBox.integer(1, 10),
      string: randBox.string(),
      name: randBox.name()
    };
  });
 
  t.true(typeof result.integer === 'number');
  t.true(typeof result.string === 'string');
  t.true(typeof result.name === 'string');
 
  await browser.close();
});

2. TypeScript 类型测试


// test/types.test.ts
import test from 'ava';
import RandBox from '../src/index';
 
test('TypeScript type definitions', t => {
  const randBox = new RandBox();
 
  // 编译时类型检查
  const num: number = randBox.integer();
  const str: string = randBox.string();
  const bool: boolean = randBox.bool();
 
  // 可选参数类型检查
  const customInt: number = randBox.integer({ min: 1, max: 10, exclude: [5] });
  const customStr: string = randBox.string({ length: 20, alpha: true });
 
  t.true(typeof num === 'number');
  t.true(typeof str === 'string');
  t.true(typeof bool === 'boolean');
});

持续集成配置

1. GitHub Actions 工作流


# .github/workflows/test.yml
name: Test Suite
 
on:
  push:
    branches: [ main, develop ]
  pull_request:
    branches: [ main ]
 
jobs:
  test:
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
        os: [ubuntu-latest, windows-latest, macos-latest]
        node-version: [16.x, 18.x, 20.x]
 
    steps:
    - uses: actions/checkout@v3
 
    - name: Use Node.js ${{ matrix.node-version }}
      uses: actions/setup-node@v3
      with:
        node-version: ${{ matrix.node-version }}
        cache: 'npm'
 
    - name: Install dependencies
      run: npm ci
 
    - name: Run linting
      run: npm run lint
 
    - name: Run type checking
      run: npm run typecheck
 
    - name: Run tests
      run: npm test
 
    - name: Run coverage
      run: npm run coverage
 
    - name: Upload coverage to Codecov
      uses: codecov/codecov-action@v3
 
  browser-test:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v3
    - uses: actions/setup-node@v3
      with:
        node-version: '18'
 
    - name: Install dependencies
      run: npm ci
 
    - name: Build for browser
      run: npm run build
 
    - name: Run browser tests
      run: npm run test:browser

2. 测试覆盖率配置


// nyc.config.js
module.exports = {
  include: ['src/**/*.ts'],
  exclude: [
    'src/**/*.test.ts',
    'src/**/*.spec.ts',
    'src/types.ts'
  ],
  reporter: ['text', 'html', 'lcov'],
  'report-dir': './coverage',
  'temp-dir': './coverage/.nyc_output',
  checkCoverage: true,
  lines: 90,
  statements: 90,
  functions: 90,
  branches: 85
};

质量保证流程

1. 代码质量检查


// .eslintrc.js
module.exports = {
  extends: [
    '@typescript-eslint/recommended',
    'plugin:jest/recommended'
  ],
  rules: {
    // 自定义规则
    'prefer-const': 'error',
    'no-var': 'error',
    '@typescript-eslint/explicit-function-return-type': 'warn',
    '@typescript-eslint/no-explicit-any': 'error'
  }
};

2. 自动化发布流程


{
  "scripts": {
    "preversion": "npm run test && npm run build",
    "version": "npm run docs:build",
    "postversion": "git push && git push --tags",
    "prepublishOnly": "npm run test && npm run build",
    "release": "semantic-release"
  }
}

3. 变更日志自动生成


// release.config.js
module.exports = {
  branches: ['main'],
  plugins: [
    '@semantic-release/commit-analyzer',
    '@semantic-release/release-notes-generator',
    '@semantic-release/changelog',
    '@semantic-release/npm',
    '@semantic-release/github'
  ]
};

测试数据管理

1. 测试数据生成器


// test/helpers/test-data-generator.js
export class TestDataGenerator {
  static generateTestCases(count = 100) {
    const cases = [];
 
    for (let i = 0; i < count; i++) {
      cases.push({
        seed: `test-${i}`,
        expected: {
          integer: this.expectedInteger(`test-${i}`),
          string: this.expectedString(`test-${i}`),
          name: this.expectedName(`test-${i}`)
        }
      });
    }
 
    return cases;
  }
 
  static expectedInteger(seed) {
    // 基于种子预计算期望值
    const randBox = new RandBox(seed);
    return randBox.integer(1, 100);
  }
}

2. 快照测试


test('output consistency snapshot test', t => {
  const randBox = new RandBox('snapshot-seed');
 
  const output = {
    integers: Array(10).fill().map(() => randBox.integer(1, 100)),
    strings: Array(5).fill().map(() => randBox.string({ length: 10 })),
    names: Array(5).fill().map(() => randBox.name()),
    emails: Array(5).fill().map(() => randBox.email())
  };
 
  t.snapshot(output, 'Random output should be consistent');
});

下期预告

在最后一篇文章中，我将分享 RandBox 的文档建设、社区运营和生态发展，包括：

现代化文档网站的构建
API 文档的自动生成
社区贡献指南的制定
插件生态的规划与实现

敬请期待《从零开始打造 RandBox（5/5）- 文档建设与生态发展》！

关于 RandBox

🏠 官网: https://randbox.top 📦 GitHub: https://github.com/027xiguapi/randbox 📚 文档: https://randbox.top/zh/docs

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