Node Server零基础： 开发环境文件自动重载

const fs = require('fs'),
    path = require('path'),
    projectRootPath = path.resolve(__dirname, './src');

const watch = project => {
    require('./src'); // 启动 APP，自动检索到 src/index.js
    try { // 监听文件夹
        fs.watch(project, { recursive: true }, cacheClean)
    } catch(e) {
        console.error('watch file error');
    }
}
// 清除缓存
const cacheClean = () => {
    Object.keys(require.cache).forEach(function (id) {
        if (/[\/\\](src)[\/\\]/.test(id)) {
            delete require.cache[id]
        }
    })
}
// 启动开发模式
watch(projectRootPath);

// 引入中间件或控制器
app.use(async (ctx, next) => {
    await require('./controllers/main.js')(ctx);
});
// 或引入路由
app.use(async (ctx, next) => {
    await require('./router').routes()(ctx, next)
})

const pm2 = require('pm2');

pm2.connect(function(err) {
    if (err) {
        console.error(err);
        process.exit(2);
    }

    pm2.start({
        "watch": ["./app"], // 开启 watch 模式，并监听 app 文件夹下的改动
        "ignore_watch": ["node_modules", "assets"], // 忽略监听的文件
        "watch_options": {
            "followSymlinks": false // 不允许符号链接
        },
        name: 'httpServer',
        script: './server/index.js', // APP 入口
        exec_mode: 'fockMode', // 开发模式下建议使用 fockModel
        instances: 1, // 仅启用 1 个 CPU
        max_memory_restart: '100M' // 当占用 100M 内存时重启 APP
    }, function(err, apps) {
        pm2.disconnect(); // Disconnects from PM2
        if (err) throw err
    });
});

const projectRootPath = path.resolve(__dirname, '..'),
    srcPath = path.join(projectRootPath, 'src'),    // 源文件
    appPath = path.join(projectRootPath, 'app'),    // 编译后输出文件夹
    devDebug = debug('dev'),
    watcher = chokidar.watch(path.join(__dirname, '../src'))

// 启动 chokidar 监听文件改动
watcher.on('ready', function () {
    // babel 编译文件夹目录
    babelCliDir({
        outDir: 'app/',
        retainLines: true,
        sourceMaps: true
    }, [ 'src/' ]) // compile all when start

    require('../app') // 启动 APP（编译后的文件）

    // 添加监听方法
    watcher
        // 文件新增
        .on('add', function (absPath) {
            compileFile('src/', 'app/', path.relative(srcPath, absPath), cacheClean)
        })
        // 文件修改
        .on('change', function (absPath) {
            compileFile('src/', 'app/', path.relative(srcPath, absPath), cacheClean)
        })
        // 文件删除
        .on('unlink', function (absPath) {
            var rmfileRelative = path.relative(srcPath, absPath)
            var rmfile = path.join(appPath, rmfileRelative)
            try {
                fs.unlinkSync(rmfile)
                fs.unlinkSync(rmfile + '.map')
            } catch (e) {
                devDebug('fail to unlink', rmfile)
                return
            }
            console.log('Deleted', rmfileRelative)
            cacheClean()； //清除缓存
        })
})

// 动态编译文件
function compileFile (srcDir, outDir, filename, cb) {
    const outFile = path.join(outDir, filename),
        srcFile = path.join(srcDir, filename);

    try {
        babelCliFile({
            outFile: outFile,
            retainLines: true,
            highlightCode: true,
            comments: true,
            babelrc: true,
            sourceMaps: true
        }, [ srcFile ], {
            highlightCode: true,
            comments: true,
            babelrc: true,
            ignore: [],
            sourceMaps: true
        })
    } catch (e) {
        console.error('Error while compiling file %s', filename, e)
        return
    }
    console.log(srcFile + ' -> ' + outFile)
    cb && cb() // 通常为清除缓存
}
// 清除缓存
function cacheClean () {
    Object.keys(require.cache).forEach(function (id) {
        if (/[\/\\](app)[\/\\]/.test(id)) {
            delete require.cache[id]
        }
    })
    console.log('App Cache Cleaned...'）
}
// 监听程序退出
process.on('exit', function (e) {
    console.log('App Quit')
})

app.use(async (ctx, next) => {
    await require('./router').routes()(ctx, next)
})