// 核心数据结构定义
class HasteMap {
  constructor(options) {
    this._options = options;
    this._cache = new Map();
    this._fileSystem = new FileSystem();
    this._crawler = new Crawler();
  }

  // 构建 haste map 的核心算法
  async build() {
    const files = await this._crawler.crawl(this._options);
    const metadata = await this._processFiles(files);

    // 使用 MapReduce 模式处理大规模文件
    const modules = this._extractModules(metadata);
    this._cache = this._indexModules(modules);

    return this._cache;
  }

  // 模块索引算法，时间复杂度 O(n log n)
  _indexModules(modules) {
    const index = new Map();

    for (const module of modules) {
      // 基于文件路径的快速哈希索引
      const key = this._generateKey(module.path);
      index.set(key, {
        ...module,
        dependencies: this._extractDependencies(module.code)
      });
    }

    return index;
  }
}

class TestScheduler {
  constructor(globalConfig, context) {
    this._globalConfig = globalConfig;
    this._context = context;
    this._workerFarm = new WorkerFarm();
  }

  // 基于工作窃取算法的任务调度
  async scheduleTests(tests, watcher) {
    const testQueues = this._partitionTests(tests);
    const workers = this._createWorkers(testQueues.length);

    const results = await Promise.allSettled(
      workers.map((worker, index) => 
        this._runWorker(worker, testQueues[index])
      )
    );

    return this._aggregateResults(results);
  }

  // 基于CPU核心数和测试复杂度的智能分区
  _partitionTests(tests) {
    const partitions = [];
    const maxWorkers = this._globalConfig.maxWorkers;

    // 基于测试执行时间的负载均衡
    const weightedTests = tests.map(test => ({
      test,
      weight: this._calculateTestWeight(test)
    }));

    weightedTests.sort((a, b) => b.weight - a.weight);

    for (let i = 0; i < maxWorkers; i++) {
      partitions[i] = [];
    }

    // 使用首次适应递减算法分配任务
    for (const {test, weight} of weightedTests) {
      const minLoadPartition = partitions.reduce((min, partition, index) => {
        const load = this._partitionLoad(partition);
        return load < min.load ? {index, load} : min;
      }, {index: 0, load: Infinity});

      partitions[minLoadPartition.index].push(test);
    }

    return partitions;
  }
}

// 内存池管理实现
class MemoryPool {
  constructor() {
    this._pool = new Map();
    this._maxSize = 1000; // 最大缓存条目数
  }

  // LRU缓存淘汰算法
  _evictIfNeeded() {
    if (this._pool.size >= this._maxSize) {
      const lruKey = this._findLRU();
      this._pool.delete(lruKey);
    }
  }

  // 基于访问时间的LRU查找
  _findLRU() {
    let lruKey = null;
    let lruTime = Infinity;

    for (const [key, value] of this._pool) {
      if (value.lastAccess < lruTime) {
        lruTime = value.lastAccess;
        lruKey = key;
      }
    }

    return lruKey;
  }
}

// jest.config.js
module.exports = {
  // 核心性能配置
  maxWorkers: '50%', // 使用50%的CPU核心
  cache: true,
  cacheDirectory: '/tmp/jest_cache',

  // 测试覆盖率和报告
  collectCoverage: true,
  coverageDirectory: 'coverage',
  coverageReporters: ['text', 'lcov', 'html'],
  coverageThreshold: {
    global: {
      branches: 80,
      functions: 80,
      lines: 80,
      statements: 80
    }
  },

  // 模块解析优化
  moduleNameMapping: {
    '^@/(.*)$': '<rootDir>/src/$1'
  },

  // 测试环境配置
  testEnvironment: 'jsdom',
  setupFilesAfterEnv: ['<rootDir>/src/setupTests.js'],

  // 性能调优参数
  testTimeout: 10000,
  verbose: true,
  bail: 1 // 遇到第一个失败测试时停止
};

// Button组件测试示例
import React from 'react';
import { render, fireEvent } from '@testing-library/react';
import Button from './Button';

describe('Button Component', () => {
  test('renders with correct text', () => {
    const { getByText } = render(<Button>Click me</Button>);
    expect(getByText('Click me')).toBeInTheDocument();
  });

  test('handles click events', () => {
    const handleClick = jest.fn();
    const { getByRole } = render(
      <Button onClick={handleClick}>Click me</Button>
    );

    fireEvent.click(getByRole('button'));
    expect(handleClick).toHaveBeenCalledTimes(1);
  });

  test('matches snapshot', () => {
    const { container } = render(<Button variant="primary">Submit</Button>);
    expect(container.firstChild).toMatchSnapshot();
  });
});

// API集成测试配置
module.exports = {
  testEnvironment: 'node',
  setupFilesAfterEnv: ['<rootDir>/test/setup.js'],
  globalSetup: '<rootDir>/test/globalSetup.js',
  globalTeardown: '<rootDir>/test/globalTeardown.js',
  testMatch: ['**/test/**/*.test.js'],

  // 模拟外部依赖
  moduleNameMapping: {
    '^@external/services': '<rootDir>/test/__mocks__/services.js'
  }
};

// 数据库测试工具
class TestDatabase {
  async setup() {
    await this.connect();
    await this.seed();
  }

  async teardown() {
    await this.cleanup();
    await this.disconnect();
  }
}

// 性能测试套件
describe('Order Service Performance', () => {
  beforeEach(async () => {
    await performanceTestSetup();
  });

  test('should handle 1000 concurrent orders', async () => {
    const promises = Array.from({ length: 1000 }, () => 
      createOrder(testOrderData)
    );

    const results = await Promise.allSettled(promises);
    const successful = results.filter(r => r.status === 'fulfilled');

    expect(successful.length).toBeGreaterThan(950); // 95%成功率
  }, 30000); // 延长超时时间

  test('order creation response time under 200ms', async () => {
    const startTime = Date.now();
    await createOrder(testOrderData);
    const endTime = Date.now();

    expect(endTime - startTime).toBeLessThan(200);
  });
});

// 微前端测试策略
const createMicroFrontendTestBed = (appConfigs) => {
  return {
    async renderCompositeApp() {
      const container = document.createElement('div');

      for (const config of appConfigs) {
        await config.mount(container);
      }

      return container;
    },

    async simulateUserJourney(steps) {
      for (const step of steps) {
        await step.execute();
        await this.waitForStableState();
      }
    }
  };
};

// 解决方案：调整超时配置并优化慢测试
{
  testTimeout: 30000,
  // 识别并优化慢测试
  slowTestThreshold: 5000
}

// 解决方案：强制垃圾回收和内存监控
afterEach(async () => {
  if (global.gc) {
    global.gc();
  }

  const used = process.memoryUsage().heapUsed / 1024 / 1024;
  if (used > 500) {
    console.warn(`Memory usage high: ${Math.round(used)}MB`);
  }
});

// 解决方案：建立快照审查流程
// 在CI环境中设置
{
  updateSnapshot: process.env.CI ? 'none' : 'new'
}

name: Jest CI Pipeline
on: [push]
jobs:
  test:
    runs-on: ubuntu-latest
    steps:

      - uses: actions/checkout@v3
      - uses: actions/setup-node@v3
        with:
          node-version: '18'

      - run: npm ci
      - run: npx jest --ci --reporters=default --reporters=jest-junit
      - uses: actions/upload-artifact@v3
        with:
          name: jest-report
          path: ./junit.xml

expect.extend({
  toBeSuccessful(response) {
    const pass = response.status >= 200 && response.status < 300;
    return {
      pass,
      message: () => `Expected ${response.status} to be a successful HTTP status`,
    };
  },
});

// 使用方式
test('API response is successful', () => {
  expect(fetch('/api/data')).toBeSuccessful();
});