Node.js: path 与 url 模块

const path = require('path');

const fullPath = path.join('/app', 'src', 'utils', 'helper.js');
console.log(fullPath);
// macOS/Linux: /app/src/utils/helper.js
// Windows:     \app\src\utils\helper.js

const path = require('path');

console.log(path.join('/app', '../config', 'settings.json'));
// /config/settings.json

console.log(path.join('src', '.', 'index.js'));
// src/index.js

const path = require('path');

console.log(path.resolve('src', 'index.js'));
// /current/working/dir/src/index.js

console.log(path.resolve('/app', 'src', 'index.js'));
// /app/src/index.js

console.log(path.resolve('/app', '/tmp', 'file.txt'));
// /tmp/file.txt（以最右侧绝对路径为准）

const path = require('path');

const parsed = path.parse('/app/src/utils/helper.js');
console.log(parsed);

{
  root: '/',
  dir: '/app/src/utils',
  base: 'helper.js',
  ext: '.js',
  name: 'helper'
}

const path = require('path');

const filePath = path.format({
  dir: '/app/src/utils',
  base: 'helper.js'
});
console.log(filePath);
// /app/src/utils/helper.js

const path = require('path');

const filePath = '/app/src/utils/helper.js';

console.log(path.extname(filePath));   // .js
console.log(path.basename(filePath));  // helper.js
console.log(path.basename(filePath, '.js')); // helper
console.log(path.dirname(filePath));   // /app/src/utils

const path = require('path');

console.log('分隔符:', JSON.stringify(path.sep));
// macOS/Linux: "/"
// Windows:     "\\"

const envPaths = process.env.PATH.split(path.delimiter);
console.log('PATH 条目数:', envPaths.length);

const url = require('url');

const parsed = url.parse('https://example.com/api/users?name=Bob&page=1');
console.log(parsed.hostname);
console.log(parsed.query);

example.com
name=Bob&page=1

const myUrl = new URL('https://example.com/api/users?name=Bob&page=1');

console.log(myUrl.hostname);
console.log(myUrl.pathname);
console.log(myUrl.searchParams.get('name'));
console.log(myUrl.searchParams.get('page'));

example.com
/api/users
Bob
1

const myUrl = new URL('https://example.com/search');
myUrl.searchParams.set('q', 'nodejs');
myUrl.searchParams.set('lang', 'zh');
myUrl.searchParams.append('tag', 'backend');
myUrl.searchParams.append('tag', 'tutorial');
myUrl.searchParams.delete('lang');

console.log(myUrl.toString());
// https://example.com/search?q=nodejs&tag=backend&tag=tutorial

console.log(myUrl.searchParams.getAll('tag'));
// [ 'backend', 'tutorial' ]

const { fileURLToPath } = require('url');

const fileUrl = 'file:///app/src/index.js';
const filePath = fileURLToPath(fileUrl);
console.log(filePath);
// macOS/Linux: /app/src/index.js
// Windows:     \app\src\index.js

const path = require('path');

console.log('__dirname:', __dirname);
console.log('__filename:', __filename);

const configPath = path.join(__dirname, 'config', 'settings.json');
console.log(configPath);

import { fileURLToPath } from 'url';
import path from 'path';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

console.log('__dirname:', __dirname);
console.log('__filename:', __filename);

const path = require('path');

// ❌ 硬编码分隔符
const bad1 = '/app/data/' + 'config.json';

// ✅ 使用 path.join
const good1 = path.join('/app', 'data', 'config.json');

// ❌ 手动拼接工作目录
const bad2 = process.cwd() + '/output/result.log';

// ✅ 使用 path.resolve
const good2 = path.resolve('output', 'result.log');

// ❌ 字符串替换分隔符
const bad3 = somePath.replace(/\\/g, '/');

// ✅ 使用 path.normalize
const good3 = path.normalize(somePath);

const path = require('path');
const { fileURLToPath } = require('url');

class PathTool {
  constructor(baseDir) {
    this.baseDir = baseDir || process.cwd();
  }

  resolveConfigPath(configRelativePath) {
    return path.resolve(this.baseDir, configRelativePath);
  }

  buildDataPath(...segments) {
    return path.join(this.baseDir, 'data', ...segments);
  }

  parseUrl(urlString) {
    const myUrl = new URL(urlString);
    return {
      protocol: myUrl.protocol,
      hostname: myUrl.hostname,
      pathname: myUrl.pathname,
      params: Object.fromEntries(myUrl.searchParams.entries())
    };
  }

  extractFileInfo(filePath) {
    const parsed = path.parse(filePath);
    return {
      directory: parsed.dir,
      fileName: parsed.name,
      extension: parsed.ext,
      fullPath: filePath
    };
  }

  toFilePath(urlOrPath) {
    if (urlOrPath.startsWith('file://')) {
      return fileURLToPath(urlOrPath);
    }
    return path.resolve(urlOrPath);
  }
}

const tool = new PathTool('/app/project');

// 1. 解析配置路径
const configPath = tool.resolveConfigPath('config/app.json');
console.log('配置路径:', configPath);
// /app/project/config/app.json

// 2. 拼接数据目录
const dataPath = tool.buildDataPath('users', 'profiles.json');
console.log('数据路径:', dataPath);
// /app/project/data/users/profiles.json

// 3. 解析 URL 并提取参数
const parsed = tool.parseUrl('https://api.example.com/v1/users?role=admin&active=true');
console.log('URL 解析:', parsed);
// { protocol: 'https:', hostname: 'api.example.com',
//   pathname: '/v1/users', params: { role: 'admin', active: 'true' } }

// 4. 提取文件信息
const info = tool.extractFileInfo('/app/project/data/users/profiles.json');
console.log('文件信息:', info);
// { directory: '/app/project/data/users',
//   fileName: 'profiles', extension: '.json', fullPath: '...' }

// 5. file URL 转文件路径
const localPath = tool.toFilePath('file:///app/project/config/app.json');
console.log('本地路径:', localPath);
// /app/project/config/app.json