combo.js

var config = require('./config');
var fs = require('fs');
var path = require('path');
var request = require('request');
/**
 * 替换路径，如/combo/tcc/tbr/1.3.3/tbr/loader.js 替换为/tcc/tbr/[src|build]]/tbr/loader.js
 * @param {String} p 传入的路径
 * @param {Boolean} withVersion 是否替换版本号
 * @returns {String} 替换后的文件路径
 **/
function replacePath(p, withVersion) {
    if (withVersion) {
        return p.replace(/^\/?combo\/?/, '');
    } else {
        return p.replace(/^\/?combo\/?/, '').replace(/(\d+\.){2}\d+/, config.combo.dist);
    }
}

/**
 * 根据文件信息加载内容并拼接到一起
 * @param {Array} fileList 处理好的文件列表
 * @returns {Object} 返回拼接后的内容和错误信息
 **/
function loadFile(fileList, callback) {
    var content = '';
    var errors = [];
    var len = fileList.length;
    var index = 0;
    var isLoadRemote = typeof callback === 'function';
    fileList.forEach(function(item) {
        var localPath = path.join(config.combo.dir, item.path);
        var remotePath = config.combo.domain + item.opath;
        localPath = localPath.split('?')[0];
        var exist = fs.existsSync(localPath);
        if(!exist) {
            console.log('文件不存在，请求线上资源: ' + remotePath);
            var options = {
                url: remotePath,
                headers: {
                    //'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.73 Safari/537.36'
                }
            };
            if (isLoadRemote) {
                request(options, function(err, res, body) {
                    if (err) {
                        console.log('线上资源请求失败：', remotePath);
                        errors.push('文件(' + localPath + ')不存在，请求线上资源也失败: ' + remotePath);
                    } else {
                        content += body;
                    }
                    index ++;
                    console.log(index + '/' + len);
                    if (index === len) {
                        console.log('资源读取完成');
                        callback && callback({
                            content: content,
                            errors: errors
                        })
                    }

                });
            }
            return;
        }
        console.log('读取文件', localPath);
        var c = fs.readFileSync(localPath, 'utf8');
        content += '/*' + localPath + '*/';//备注文件地址
        content += c;
        index ++;
        console.log(index + '/' + len);
        if (index === len) {
            console.log('资源读取完成');
            callback && callback({
                content: content,
                errors: errors
            })
        }
    });
    if (!isLoadRemote) {
        return {
            content: content,
            errors: errors
        }
    }
}

module.exports = function(req, res, obj) {
    //console.log(obj);
    var search = obj.search;
    var pathName = obj.pathname;
    var href = obj.href;
    var files = [];
    if (search && search.indexOf('??') > -1) {
        var searchArray = search.substr(2).split(',');
        searchArray.forEach(function(item) {
            var p = path.join(pathName, item);
            files.push({
                opath: replacePath(p, true),
                path: replacePath(p)
            });
        })
    } else {
        files.push({
            opath: replacePath(pathName, true),
            path: replacePath(pathName)
        });
    }
    loadFile(files, function(results) {
        if (results.errors < 1) {
            if (href.indexOf('js') > -1) {
                res.type('application/x-javascript');
            } else if (href.indexOf('css') > -1) {
                res.type('text/css');
            }
            res.send(results.content);
        } else {
            res.send(results.errors.join('<br/>'))
        }
    })
    
}