前言
开发钉钉 H5 微应用中，不同于平常的build，前端需要把文件打成压缩包上传至平台。同样的机制在另外一些阿里系产品也类似，例如浙里办、浙政钉。相较于一键执行脚本，手动压缩文件容易出错。我通过node-archiver这个包简单地实现了压缩，并在此向大家介绍。
使用 node-archiver 压缩
安装依赖
npm install archiver -D
由于不会在生产环境使用，安装在devDependencies即可。
阅读官方示例，快速上手
// require modules
const fs = require('fs');
const archiver = require('archiver');
// create a file to stream archive data to.
const output = fs.createWriteStream(__dirname + '/example.zip');
const archive = archiver('zip', {
zlib: { level: 9 } // Sets the compression level.
});
// listen for all archive data to be written
// 'close' event is fired only when a file descriptor is involved
output.on('close', function() {
console.log(archive.pointer() + ' total bytes');
console.log('archiver has been finalized and the output file descriptor has closed.');
});
// This event is fired when the data source is drained no matter what was the data source.
// It is not part of this library but rather from the NodeJS Stream API.
// @see: https://nodejs.org/api/stream.html#stream_event_end
output.on('end', function() {
console.log('Data has been drained');
});
// good practice to catch warnings (ie stat failures and other non-blocking errors)
archive.on('warning', function(err) {
if (err.code === 'ENOENT') {
// log warning
} else {
// throw error
throw err;
}
});
// good practice to catch this error explicitly
archive.on('error', function(err) {
throw err;
});
// pipe archive data to the file
archive.pipe(output);
// append a file from stream
const file1 = __dirname + '/file1.txt';
archive.append(fs.createReadStream(file1), { name: 'file1.txt' });
// append a file from string
archive.append('string cheese!', { name: 'file2.txt' });
// append a file from buffer
const buffer3 = Buffer.from('buff it!');
archive.append(buffer3, { name: 'file3.txt' });
// append a file
archive.file('file1.txt', { name: 'file4.txt' });
// append files from a sub-directory and naming it `new-subdir` within the archive
archive.directory('subdir/', 'new-subdir');
// append files from a sub-directory, putting its contents at the root of archive
archive.directory('subdir/', false);
// append files from a glob pattern
archive.glob('file*.txt', {cwd:__dirname});
// finalize the archive (ie we are done appending files but streams have to finish yet)
// 'close', 'end' or 'finish' may be fired right after calling this method so register to them beforehand
archive.finalize();
这个示例还是比较简洁的，做了以下几个动作：
- 引入依赖以及文件处理系统
fs模块。 - 创建一个写入流并定义压缩等级（1-9）。
- 发起各类监听，主要用于打印日志及在异常时结束进程。
- 创建一个
pipe(管道)，用以传输数据。 - 通过
file、directory、buffer等api写入数据。实际使用中在，写入之前，可以通过fs.readdirSync或其它方法拿到数据。 - 通过
finalize关闭流。
个人完整代码实现
// 项目根目录下 export-zip.js
const fs = require("fs"),
archiver = require("archiver");
//这里是当前目录路径
const homedir = __dirname,
// 日期充当hash值防止覆盖之前的压缩包
timeString = new Date().toLocaleDateString().replace(///g, "-");
//配置要打包的路径列表,需要打包某些目录，添加到数组里面即可 相对路径
const directories = [],
files = [];
fs.readdirSync(homedir).forEach((pathname) => {
if (
fs.statSync(pathname).isDirectory() &&
["public", "src"].includes(pathname)
) {
directories.push(pathname);
} else if (
!fs.statSync(pathname).isDirectory() &&
!pathname.includes(".zip")
) {
files.push(pathname);
}
});
// 默认在当前目录路径生成此文件 demo.当前日期.zip
const filedir = `demo.${timeString}.zip`;
const output = fs.createWriteStream(`${homedir}/${filedir}`);
const archive = archiver("zip", {
zlib: { level: 9 }, // 设置压缩级别
});
archive.on("error", function (err) {
throw err;
});
output.on("close", function () {
console.log(`
--------- ---------压缩完毕--------- ---------
生成文件大小${(archive.pointer() / 1024 / 1024).toFixed(1)}MB
请在当前项目路径下寻找 ${filedir} 文件,系统路径为 ${homedir}\${filedir}
`);
});
archive.pipe(output);
for (let direcoty of directories) {
archive.directory(direcoty, direcoty);
}
for (let file of files) {
archive.file(file, { name: file });
}
archive.finalize();
添加指令
// package.json
{
"scripts": {
"zip": "node export-zip.js"
},
}
总结
整体而言，使用node-archiver压缩还是比较简单方便的。需要注意的是，我在开发时使用的是windows系统，并不清楚fs模块在其他系统上有无差异，具体在使用时请再做分析。
