gulp基础

什么是gulp

gulp

是可以自动化执行任务的工具在平时开发的流程里面,一定有一些任务需要手工重复得执行，比如:
- 把文件从开发目录拷贝到生产目录
- 把多个 JS 或者 CSS 文件合并成一个文件
- 对JS文件和CSS进行压缩
- 把sass或者less文件编译成CSS
- 压缩图像文件
- 创建一个可以实时刷新页面内容的本地服务器
  
  只要你觉得有些动作是要重复去做的,就可以把这些动作创建成一个gulp任务,然后在指定的条件下自动执行

gulp特点

易于使用通过代码优于配置的策略,Gulp 让简单的任务简单，复杂的任务可管理
快速构建利用 node.js 流的威力,你可以快速构建项目并减少频繁的 IO 操作
高质量的插件 Gulp 严格的插件指南确保插件如你期望的那样简洁地工作
易于学习通过最少的 API，掌握 gulp 毫不费力，构建工作尽在掌握

安装gulp

quick-start

npm install --g gulp-cli
npm install --save-dev gulp

异步任务和组合任务

gulpfile.js

const fs = require('fs');
const through = require('through2');
const { series, parallel } = require('gulp');
function callbackTask(done) {
    setTimeout(() => {
        console.log('callbackTask');
        done();
    }, 1000);
}
function promiseTask() {
    return new Promise((resolve) => {
        setTimeout(() => {
            console.log('promiseTask');
            resolve();
        }, 1000);
    });
}
async function asyncTask() {
    await new Promise((resolve) => {
        setTimeout(() => {
            resolve();
        }, 1000);
    });
    console.log('asyncTask');
}
function streamTask() {
    return fs.createReadStream('input.txt')
        .pipe(through((chunk, encoding, next) => {
            setTimeout(() => {
                next(null, chunk);
            }, 1000);
        }))
        .pipe(fs.createWriteStream('output.txt'))
}

const parallelTask = parallel(callbackTask, promiseTask, asyncTask, streamTask);
const seriesTask = series(callbackTask, promiseTask, asyncTask, streamTask);
exports.callback = callbackTask
exports.promise = promiseTask
exports.async = asyncTask
exports.stream = streamTask
exports.parallel = parallelTask
exports.series = seriesTask

gulp核心API

gulp.src()

gulp.src()方法正是用来获取流的
注意这个流里的内容不是原始的文件流,而是一个虚拟文件对象流
globs 参数是文件匹配模式(类似正则表达式)，用来匹配文件路径(包括文件名)，当然这里也可以直接指定某个具体的文件路径。当有多个匹配模式时，该参数可以为一个数组
options 为可选参数

gulp.src(globs[, options])

gulp.dest()

```
  gulp.dest()
```
是用来向硬盘写入文件的
- path 为写入文件的路径
- options 为一个可选的参数对象
gulp.dest()传入的路径参数只能用来指定要生成的文件的目录,而不能指定生成文件的文件名它生成文件的文件名使用的是导入到它的文件流自身的文件名所以生成的文件名是由导入到它的文件流决定的
gulp.dest(path)生成的文件路径是我们传入的path参数后面再加上gulp.src()中有通配符开始出现的那部分路径
通过指定gulp.src()方法配置参数中的base属性，我们可以更灵活的来改变gulp.dest()生成的文件路径

gulp.dest(path[,options])

pipe

gulpfile.js

const { src, dest } = require('gulp');
function copyTask() {
    console.log('执行拷贝任务');
    return src('src/**/*.js').pipe(dest('dist'));
}
exports.default = copyTask;

gulp实战

安装

cnpm install @babel/core @babel/preset-env browser-sync gulp gulp-babel gulp-clean gulp-clean-css gulp-ejs gulp-htmlmin gulp-if gulp-imagemin gulp-less gulp-load-plugins gulp-uglify gulp-useref gulp-watch map-stream bootstrap jquery --save

编译样式

const { src, dest } = require('gulp');
const less = require('gulp-less');
const styles = () => {
    return src("src/styles/*.less", { base: 'src' })
        .pipe(less())
        .pipe(dest('dist'))
}

exports.styles = styles;

编译脚本

const { src, dest } = require('gulp');
const less = require('gulp-less');
const babel = require('gulp-babel');
const styles = () => {
    return src("src/styles/*.less", { base: 'src' })
        .pipe(less())
        .pipe(dest('dist'))
}

+const scripts = () => {
+    return src("src/scripts/*.js", { base: 'src' })
+        .pipe(babel({
+            presets: ["@babel/preset-env"]
+        }))
+        .pipe(dest('dist'))
+}

exports.styles = styles;
+exports.scripts = scripts;

编译html

src\index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title><%=title%></title>
        <link rel="stylesheet" href="node_modules/bootstrap/dist/css/bootstrap.css"/>
    <link rel="stylesheet" href="styles/main.css"/>
</head>
<body>
    <button class="btn btn-danger">按钮</button>
    <img src="assets/images/circle.svg"/>
    <img src="rect.svg"/>
    <script src="node_modules/jquery/dist/jquery.js"></script>
    <script src="scripts/main.js"></script>
</body>
</html>

circle.svg

src\assets\images\circle.svg

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="100" height="100" version="1.1" xmlns="http://www.w3.org/2000/svg">
 <circle cx="50" cy="50" r="50"  fill="red"/>
</svg>

static\rect.svg

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="100" height="100" version="1.1" xmlns="http://www.w3.org/2000/svg">
 <rect  width="100" height="100" style="fill:red;"/>
</svg>

gulpfile.js

const { src, dest, parallel } = require('gulp');
const less = require('gulp-less');
const babel = require('gulp-babel');
const ejs = require('gulp-ejs');
const styles = () => {
    return src("src/styles/*.less", { base: 'src' })
        .pipe(less())
        .pipe(dest('dist'))
}

const scripts = () => {
    return src("src/scripts/*.js", { base: 'src' })
        .pipe(babel({
            presets: ["@babel/preset-env"]
        }))
        .pipe(dest('dist'))
}

+const html = () => {
+    return src("src/*.html", { base: 'src' })
+        .pipe(ejs({ title: 'gulp' }))
+        .pipe(dest('dist'))
+}
exports.styles = styles;
exports.scripts = scripts;
+exports.html = html;

编译任务

const { src, dest, parallel } = require('gulp');
const less = require('gulp-less');
const babel = require('gulp-babel');
const ejs = require('gulp-ejs');
const styles = () => {
    return src("src/styles/*.less", { base: 'src' })
        .pipe(less())
        .pipe(dest('dist'))
}

const scripts = () => {
    return src("src/scripts/*.js", { base: 'src' })
        .pipe(babel({
            presets: ["@babel/preset-env"]
        }))
        .pipe(dest('dist'))
}

const html = () => {
    return src("src/*.html", { base: 'src' })
        .pipe(ejs({ title: 'gulp' }))
        .pipe(dest('dist'))
}
+const compile = parallel(styles, scripts, html);
exports.styles = styles;
exports.scripts = scripts;
exports.html = html;
+exports.compile = compile;

压缩图片

安装

npm install gulp-imagemin --save-dev
npm install imagemin-jpegtran imagemin-svgo imagemin-gifsicle imagemin-optipng --save-dev

gulpfile.js

const { src, dest, parallel } = require('gulp');
const less = require('gulp-less');
const babel = require('gulp-babel');
const ejs = require('gulp-ejs');
const styles = () => {
    return src("src/styles/*.less", { base: 'src' })
        .pipe(less())
        .pipe(dest('dist'))
}

const scripts = () => {
    return src("src/scripts/*.js", { base: 'src' })
        .pipe(babel({
            presets: ["@babel/preset-env"]
        }))
        .pipe(dest('dist'))
}

const html = () => {
    return src("src/*.html", { base: 'src' })
        .pipe(ejs({ title: 'gulp' }))
        .pipe(dest('dist'))
}

+const images = async () => {
+    let imagemin = await import('gulp-imagemin');
+    return src("src/assets/images/**/*.@(jpg|png|gif|svg)", { base: 'src' })
+        .pipe(imagemin.default())
+        .pipe(dest('dist'))
+}

const compile = parallel(styles, scripts, html);
exports.styles = styles;
exports.scripts = scripts;
exports.html = html;
exports.compile = compile;
+exports.images = images;

拷贝静态文件

const { src, dest, parallel } = require('gulp');
const less = require('gulp-less');
const babel = require('gulp-babel');
const ejs = require('gulp-ejs');
const styles = () => {
    return src("src/styles/*.less", { base: 'src' })
        .pipe(less())
        .pipe(dest('dist'))
}

const scripts = () => {
    return src("src/scripts/*.js", { base: 'src' })
        .pipe(babel({
            presets: ["@babel/preset-env"]
        }))
        .pipe(dest('dist'))
}

const html = () => {
    return src("src/*.html", { base: 'src' })
        .pipe(ejs({ title: 'gulp' }))
        .pipe(dest('dist'))
}

const images = async () => {
    let imagemin = await import('gulp-imagemin');
    return src("src/assets/images/**/*.@(jpg|png|gif|svg)", { base: 'src' })
        .pipe(imagemin.default())
        .pipe(dest('dist'))
}

+const static = async () => {
+    return src("static/**", { base: 'static' })
+        .pipe(dest('dist'))
+}

const compile = parallel(styles, scripts, html);
+const build = parallel(compile, static)
exports.styles = styles;
exports.scripts = scripts;
exports.html = html;
exports.compile = compile;
exports.images = images;
+exports.static = static;
+exports.build = build;

删除输出目录

const { src, dest, parallel, series } = require('gulp');
const less = require('gulp-less');
const babel = require('gulp-babel');
const ejs = require('gulp-ejs');
+const gulpClean = require('gulp-clean');
const styles = () => {
    return src("src/styles/*.less", { base: 'src' })
        .pipe(less())
        .pipe(dest('dist'))
}

const scripts = () => {
    return src("src/scripts/*.js", { base: 'src' })
        .pipe(babel({
            presets: ["@babel/preset-env"]
        }))
        .pipe(dest('dist'))
}

const html = () => {
    return src("src/*.html", { base: 'src' })
        .pipe(ejs({ title: 'gulp' }))
        .pipe(dest('dist'))
}

const images = async () => {
    let imagemin = await import('gulp-imagemin');
    return src("src/assets/images/**/*.@(jpg|png|gif|svg)", { base: 'src' })
        .pipe(imagemin.default())
        .pipe(dest('dist'))
}

const static = async () => {
    return src("static/**", { base: 'static' })
        .pipe(dest('dist'))
}
+const clean =  () => {
+    return src("dist/**", { read: false })
+        .pipe(gulpClean())
+}
const compile = parallel(styles, scripts, html);
+const build = series(clean, parallel(compile, static));
exports.styles = styles;
exports.scripts = scripts;
exports.html = html;
exports.compile = compile;
exports.images = images;
exports.static = static;
exports.build = build;
+exports.clean = clean;

自动加载插件

const { src, dest, parallel, series } = require('gulp');
-const less = require('gulp-less');
-const babel = require('gulp-babel');
-const ejs = require('gulp-ejs');
-const gulpClean = require('gulp-clean');
+const plugins = require('gulp-load-plugins')();
const styles = () => {
    return src("src/styles/*.less", { base: 'src' })
+       .pipe(plugins.less())
        .pipe(dest('dist'))
}

const scripts = () => {
    return src("src/scripts/*.js", { base: 'src' })
+       .pipe(plugins.babel({
            presets: ["@babel/preset-env"]
        }))
        .pipe(dest('dist'))
}

const html = () => {
    return src("src/*.html", { base: 'src' })
+       .pipe(plugins.ejs({ title: 'gulp' }))
        .pipe(dest('dist'))
}

const images = async () => {
     let imagemin = await import('gulp-imagemin');
    return src("src/assets/images/**/*.@(jpg|png|gif|svg)", { base: 'src' })
        .pipe(imagemin.default())
        .pipe(dest('dist'))
}

const static = async () => {
    return src("static/**", { base: 'static' })
        .pipe(dest('dist'))
}
const clean =  () => {
    return src("dist/**", { read: false })
+       .pipe(plugins.clean())
}
const compile = parallel(styles, scripts, html);
const build = series(clean, parallel(compile, static));
exports.styles = styles;
exports.scripts = scripts;
exports.html = html;
exports.compile = compile;
exports.images = images;
exports.static = static;
exports.build = build;
exports.clean = clean;

开发服务器

gulpfile.js

const { src, dest, parallel, series } = require('gulp');
const plugins = require('gulp-load-plugins')();
+const browserSync = require('browser-sync');
+const path = require('path');
const styles = () => {
    return src("src/styles/*.less", { base: 'src' })
        .pipe(plugins.less())
        .pipe(dest('dist'))
}

const scripts = () => {
    return src("src/scripts/*.js", { base: 'src' })
        .pipe(plugins.babel({
            presets: ["@babel/preset-env"]
        }))
        .pipe(dest('dist'))
}

const html = () => {
    return src("src/*.html", { base: 'src' })
        .pipe(plugins.ejs({ title: 'gulp' }))
        .pipe(dest('dist'))
}

const images = async () => {
    let imagemin = await import('gulp-imagemin');
    return src("src/assets/images/**/*.@(jpg|png|gif|svg)", { base: 'src' })
        .pipe(imagemin.default())
        .pipe(dest('dist'))
}

const static = async () => {
    return src("static/**", { base: 'static' })
        .pipe(dest('dist'))
}
const clean = () => {
    return src("dist/**", { read: false })
        .pipe(plugins.clean())
}
+const serve = () => {
+    return browserSync.create().init({
+        notify: false,
+        server: {
+            baseDir: 'dist',
+            routes: {
+                '/node_modules': path.resolve('node_modules')
+            }
+        }
+    });
+}
const compile = parallel(styles, scripts, html);
const build = series(clean, parallel(compile, static));
exports.styles = styles;
exports.scripts = scripts;
exports.html = html;
exports.compile = compile;
exports.images = images;
exports.static = static;
exports.build = build;
exports.clean = clean;
+exports.serve = serve;

6.10.2 main.js

src\scripts\main.js

let sum = (a, b) => a + b;
sum(1, 3)
+$(() => {
+    console.log('jquery');
+});

监听文件变化

gulpfile.js

const { src, dest, parallel, series, watch } = require('gulp');
const plugins = require('gulp-load-plugins')();
const browserSync = require('browser-sync');
const path = require('path');
+const browserServer = browserSync.create();
const styles = () => {
    return src("src/styles/*.less", { base: 'src' })
        .pipe(plugins.less())
        .pipe(dest('dist'))
}

const scripts = () => {
    return src("src/scripts/*.js", { base: 'src' })
        .pipe(plugins.babel({
            presets: ["@babel/preset-env"]
        }))
        .pipe(dest('dist'))
}

const html = () => {
    return src("src/*.html", { base: 'src' })
+       .pipe(plugins.ejs({ title: 'gulp' }, { cache: false }))
        .pipe(dest('dist'))
}

const images = async () => {
    let imagemin = await import('gulp-imagemin');
    return src("src/assets/images/**/*.@(jpg|png|gif|svg)", { base: 'src' })
        .pipe(imagemin.default())
        .pipe(dest('dist'))
}

const static = async () => {
    return src("static/**", { base: 'static' })
        .pipe(dest('dist'))
}
const clean = () => {
    return src("dist/**", { read: false })
        .pipe(plugins.clean())
}
const serve = () => {
+   watch("src/styles/*.less", styles);
+   watch("src/scripts/*.js", scripts);
+   watch("src/*.html", html);
+   watch([
+       "src/assets/images/**/*.@(jpg|png|gif|svg)",
+       "static/**"
+   ], browserServer.reload);
    return browserServer.init({
        notify: false,
+       files: ['dist/**'],
        server: {
+           baseDir: ['dist', 'src', 'static'],
            routes: {
                '/node_modules': path.resolve('node_modules')
            }
        }
    });
}
const compile = parallel(styles, scripts, html);
+const build = series(clean, parallel(compile, images, static));
+const dev = series(clean, compile, serve);
exports.styles = styles;
exports.scripts = scripts;
exports.html = html;
exports.compile = compile;
exports.images = images;
exports.static = static;
exports.clean = clean;
exports.serve = serve;
+exports.build = build;
+exports.dev = dev;

合并和压缩

src\index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title><%=title%></title>
+   <!-- build:css styles/dist.css  -->
    <link rel="stylesheet" href="node_modules/bootstrap/dist/css/bootstrap.css"/>
    <link rel="stylesheet" href="styles/main.css"/>
+   <!-- endbuild -->
</head>
<body>
    <button class="btn btn-danger">按钮</button>
    <img src="assets/images/circle.svg"/>
    <img src="rect.svg"/>
+   <!-- build:js scripts/dist.js  -->
    <script src="node_modules/jquery/dist/jquery.js"></script>
    <script src="scripts/main.js"></script>
+   <!-- endbuild -->
</body>
</html>

gulpfile.js

const { src, dest, parallel, series, watch } = require('gulp');
const plugins = require('gulp-load-plugins')();
const browserSync = require('browser-sync');
const path = require('path');
const browserServer = browserSync.create();
const styles = () => {
    return src("src/styles/*.less", { base: 'src' })
        .pipe(plugins.less())
+       .pipe(dest('temp'))
}

const scripts = () => {
    return src("src/scripts/*.js", { base: 'src' })
        .pipe(plugins.babel({
            presets: ["@babel/preset-env"]
        }))
+       .pipe(dest('temp'))
}

const html = () => {
    return src("src/*.html", { base: 'src' })
        .pipe(plugins.ejs({ title: 'gulp' }, { cache: false }))
+       .pipe(dest('temp'))
}

const images = async () => {
    let imagemin = await import('gulp-imagemin');
    return src("src/assets/images/**/*.@(jpg|png|gif|svg)", { base: 'src' })
        .pipe(imagemin.default())
        .pipe(dest('dist'))
}

const static = async () => {
    return src("static/**", { base: 'static' })
        .pipe(dest('dist'))
}
const clean = () => {
+   return src(["dist/**", "temp/**"], { read: false })
+       .pipe(plugins.clean({ allowEmpty: true }));
}
const serve = () => {
    watch("src/styles/*.less", styles);
    watch("src/scripts/*.js", scripts);
    watch("src/*.html", html);
    watch([
        "src/assets/images/**/*.@(jpg|png|gif|svg)",
        "static/**"
    ], browserServer.reload);
    return browserServer.init({
        notify: false,
        files: ['dist/**'],
        server: {
+           baseDir: ['temp', 'src', 'static'],
            routes: {
                '/node_modules': path.resolve('node_modules')
            }
        }
    });
}

+const concat = () => {
+    return src('temp/*.html', { base: 'temp' })
+        .pipe(plugins.useref({
+            searchPath: ['temp', '.']
+        }))
+        .pipe(plugins.if('*.html', plugins.htmlmin({
+            collapseWhitespace: true,
+            minifyCSS: true,
+            minifyJS: true
+        })))
+        .pipe(plugins.if('*.js', plugins.uglify()))
+        .pipe(plugins.if('*.css', plugins.cleanCss()))
+        .pipe(dest('dist'));
+}

const compile = parallel(styles, scripts, html);
+const build = series(clean, parallel(series(compile, concat), images, static));
const dev = series(clean, compile, serve);
-exports.styles = styles;
-exports.scripts = scripts;
-exports.html = html;
-exports.compile = compile;
-exports.images = images;
-exports.static = static;
-exports.serve = serve;
-exports.concat = concat;
-exports.clean = clean;
-exports.build = build;
-exports.dev = dev;

+module.exports = {
+    clean,
+    build,
+    dev
+}

glob相关

gulp内部使用了node-glob模块来实现其文件匹配功能

glob规则

匹配符	说明
*	匹配文件路径中的0个或多个字符，但不会匹配路径分隔符
**	匹配路径中的0个或多个目录及其子目录
?	匹配文件路径中的一个字符(不会匹配路径分隔符)
[...]	匹配方括号中出现的字符中的任意一个，当方括号中第一个字符为^或!时，则表示不匹配方括号中出现的其他字符中的任意一个
!(pattern1	pattern2	pattern3)	匹配任何与括号中给定的任一模式都不匹配的
?(pattern1	pattern2	pattern3)	匹配括号中给定的任一模式0次或1次，类似于js正则中的(pattern1	pattern2	pattern3)?
+(pattern1	patter2n	pattern3)	匹配括号中给定的任一模式至少1次，类似于js正则中的(pattern1	pattern2	pattern3)+
(pattern1	pattern2	pattern3)	匹配括号中给定的任一模式0次或多次，类似于js正则中的(pattern1	pattern2	pattern3)*
@(pattern1	pattern2	pattern3)	匹配括号中给定的任一模式1次，类似于js正则中的(pattern1	pattern2	pattern3)

glob示例

glob	匹配
*	能匹配 a.js,x.y,abc,abc/,但不能匹配a/b.js
.	a.js,style.css,a.b,x.y
//*.js	能匹配 a/b/c.js,x/y/z.js,不能匹配a/b.js,a/b/c/d.js
**	能匹配 abc,a/b.js,a/b/c.js,x/y/z,x/y/z/a.b,能用来匹配所有的目录和文件
a/**/z	能匹配 a/z,a/b/z,a/b/c/z,a/d/g/h/j/k/z
a/**b/z	能匹配 a/b/z,a/sb/z,但不能匹配a/x/sb/z,因为只有单**单独出现才能匹配多级目录
?.js	能匹配 a.js,b.js,c.js
a??	能匹配 a.b,abc,但不能匹配ab/,因为它不会匹配路径分隔符
[xyz].js	只能匹配 x.js,y.js,z.js,不会匹配xy.js,xyz.js等,整个中括号只代表一个字符
[^xyz].js	能匹配 a.js,b.js,c.js等,不能匹配x.js,y.js,z.js

环节实现

实现gulp

安装依赖

npm install fs-extra undertaker vinyl-fs --save

gulpfile.js

const { series, parallel } = require('gulp');
const defaultTask = (done) => {
    console.log('defaultTask');
    done();
}

const oneTask = (done) => {
    setTimeout(() => {
        console.log('oneTask');
        done();
    }, 1000);
}
const twoTask = (done) => {
    setTimeout(() => {
        console.log('twoTask');
        done();
    }, 1000);
}
const threeTask = (done) => {
    setTimeout(() => {
        console.log('threeTask');
        done();
    }, 1000);
}

const seriesTask = series(oneTask, twoTask, threeTask);
const parallelTask = parallel(oneTask, twoTask, threeTask);
exports.default = defaultTask;
exports.series = seriesTask;
exports.parallel = parallelTask;

package.json

{
  "main": "lib/index.js",
  "bin": {
    "gulp4": "./bin/gulp4.js"
  }
}

bin\gulp4.js

#!/usr/bin/env node
const path = require('path');
const gulpInst = require('../lib');
const logEvents = require('./logEvents');
const registerExports = require('./register-exports');
logEvents(gulpInst);
const taskName = process.argv[2];
const toRun = taskName || 'default';
const configPath = path.join(process.cwd(), 'gulpfile.js');
console.log(`Using gulpfile ${configPath}`);
const exported = require(configPath);
registerExports(gulpInst, exported);
gulpInst.parallel(toRun)(() => { console.log('done') });

bin\logEvents.js

function logEvents(gulpInst) {
    gulpInst.on('start', function (evt) {
        console.log(`Starting ${evt.name} ...`);
    });
    gulpInst.on('stop', function (evt) {
        console.log(`Finished ${evt.name} after ${evt.duration[0]} ms`);
    });
}
module.exports = logEvents;

bin\register-exports.js

function registerExports(gulpInst, tasks) {
    let taskNames = Object.keys(tasks);
    taskNames.forEach(taskName => {
        gulpInst.task(taskName, tasks[taskName]);
    });
}
module.exports = registerExports;

lib\index.js

const util = require('util');
const Undertaker = require('undertaker');
function Gulp() {
    Undertaker.call(this);
    this.task = this.task.bind(this);
    this.series = this.series.bind(this);
    this.parallel = this.parallel.bind(this);
}
util.inherits(Gulp, Undertaker);
const inst = new Gulp();
module.exports = inst;

实现undertaker

undertaker 是一个用于管理任务的 Node.js 模块，主要用于构建自动化工作流，特别是在构建工具如 Gulp 中非常常用。undertaker 提供了一种定义、组合和运行任务的机制，允许开发者创建复杂的任务序列和并行任务处理。undertaker 通常与 Gulp 一起使用，提供了强大的任务管理和自动化构建能力。

www.npmjs.com/package/und…
主要功能
- 任务定义：使用 undertaker 可以定义单个任务，每个任务都是一个函数。
- 任务组合：支持将多个任务组合成一个任务，任务可以是串行（顺序执行）或者并行（同时执行）。
- 任务运行：可以运行单个任务或者任务组合，并且可以监听任务的开始、完成和错误等事件。

npm使用示例

var fs = require('fs');
var Undertaker = require('undertaker');

var taker = new Undertaker();

taker.task('task1', function(cb){
  // do things

  cb(); // when everything is done
});

taker.task('task2', function(){
  return fs.createReadStream('./myFile.js')
    .pipe(fs.createWriteStream('./myFile.copy.js'));
});

taker.task('task3', function(){
  return new Promise(function(resolve, reject){
    // do things

    resolve(); // when everything is done
  });
});

// 串行执行任务
taker.task('combined', taker.series('task1', 'task2'));

// 并行执行任务
taker.task('all', taker.parallel('combined', 'task3'));

实现

lib\index.js

const util = require('util');
+const Undertaker = require('./undertaker');
function Gulp() {
    Undertaker.call(this);
    this.task = this.task.bind(this);
    this.series = this.series.bind(this);
    this.parallel = this.parallel.bind(this);
}
util.inherits(Gulp, Undertaker);
const inst = new Gulp();
module.exports = inst;

undertaker.js

lib\undertaker.js

let { inherits } = require('util');
let EventEmitter = require('events')
function Undertaker() {
    EventEmitter.call(this);
    this._tasks = {};
}
inherits(Undertaker, EventEmitter);
function task(name, fn) {
    this._tasks[name] = fn;
}
function series() {
    let args = Array.from(arguments);
    let fn = buildSeries(args);
    return fn.bind(this);
}
function parallel() {
    let args = Array.from(arguments);
    let fn = buildParallel(args);
    return fn.bind(this);;
}
function run(taskName, done) {
    let fn = this._tasks[taskName];
    fn(done);
}
Undertaker.prototype.task = task;
Undertaker.prototype.series = series;
Undertaker.prototype.parallel = parallel;
Undertaker.prototype.run = run;
function buildSeries(values) {
    function series(done) {
        let length = values.length;
        let idx = 0;
        let results = [];
        const next = (idx) => {
            let value = values[idx];
            if (typeof value !== 'function') {
                value = this._tasks[value];
            }
            let startHr = process.hrtime();
            this.emit('start', { name: value.name });
            value((err, result) => {
                this.emit('stop', { name: value.name, duration: process.hrtime(startHr) });
                results[idx] = result;
                if (++idx >= length) {
                    done(err, results);
                } else {
                    next(idx);
                }
            });
        }
        next(idx);
    }
    return series;
}
function buildParallel(values) {
    function parallel(done) {
        let length = values.length;
        let count = length;
        let results = [];
        const next = (idx) => {
            let value = values[idx];
            if (typeof value !== 'function') {
                value = this._tasks[value];
            }
            let startHr = process.hrtime();
            this.emit('start', { name: value.name });
            value((err, result) => {
                this.emit('stop', { name: value.name, duration: process.hrtime(startHr) });
                results[idx] = result;
                if (--count === 0) {
                    done(err, results);
                }
            });
        }
        for (idx = 0; idx < length; idx++) {
            next(idx);
        }
    }
    return parallel;
}
module.exports = Undertaker;

使用流操作

gulpfile.js

const { src, dest } = require('gulp');
const defaultTask = () => {
    return src('src/scripts/**/*.js').pipe(dest('dist'));
}

exports.default = defaultTask;

# 执行
gulp

vinyl-fs

vinyl-fs基础

glob

gulp内部使用了node-glob模块来实现其文件匹配功能

匹配符	说明
星	匹配文件路径中的0个或多个字符，但不会匹配路径分隔符
星星	匹配路径中的0个或多个目录及其子目录
?	匹配文件路径中的一个字符(不会匹配路径分隔符)
[...]	匹配方括号中出现的字符中的任意一个，当方括号中第一个字符为^或!时，则表示不匹配方括号中出现的其他字符中的任意一个
!(pattern1/pattern2/pattern3)	匹配任何与括号中给定的任一模式都不匹配的
?(pattern1/pattern2/pattern3)	匹配括号中给定的任一模式0次或1次
+(pattern1/patter2n/pattern3)	匹配括号中给定的任一模式至少1次
(pattern1/pattern2/pattern3)	匹配括号中给定的任一模式0次或多次
@(pattern1/pattern2/pattern3)	匹配括号中给定的任一模式1次

glob-stream.js

const { Readable } = require('stream');
let { inherits } = require('util');
let { Glob } = require('glob');
var globParent = require('glob-parent');
var toAbsoluteGlob = require('to-absolute-glob');
function GlobStream(glob, opt = {}) {
    opt.cwd = opt.cwd || process.cwd();
    Readable.call(this, { objectMode: true });
    let absoluteGlob = toAbsoluteGlob(glob, opt);
    let basePath = globParent(absoluteGlob);
    let globber = new Glob(absoluteGlob, opt);
    this._globber = globber;
    globber.on('match', (filepath) => {
        let obj = {
            cwd: opt.cwd,
            base: basePath,
            path: filepath
        };
        this.push(obj);
    });
    globber.once('end', () => {
        this.push(null);
    });
}
inherits(GlobStream, Readable);

GlobStream.prototype._read = function () {
    this._globber.resume();
};
module.exports = GlobStream;
let GlobStream = require('./glob-stream');
const glob = 'src/scripts/**/*.js';
let gs = new GlobStream(glob);
gs.on('data', (data) => {
    console.log(data);
});

vinyl-fs介绍

vinyl-fs 是一个用于文件操作的 Node.js 模块，它是 Gulp 生态系统的一部分。vinyl-fs 提供了一种使用流（streams）来读取、写入和操作文件的方式。

主要功能
- 文件读取：从文件系统读取文件并将它们转换为 Vinyl 文件对象。
- 文件写入：将 Vinyl 文件对象写回到文件系统中。
- 文件操作：提供了一些常见的文件操作方法，如重命名、过滤、匹配等。

使用 vinyl-fs 来读取和写入文件示例

const vfs = require('vinyl-fs');
const through = require('through2');

function transformFile() {
  return through.obj(function (file, enc, cb) {
    // 在这里可以对文件内容进行修改
    if (file.isBuffer()) {
      const content = file.contents.toString(enc);
      const transformedContent = content.toUpperCase(); // 将文件内容转为大写
      file.contents = Buffer.from(transformedContent, enc);
    }
    cb(null, file);
  });
}

// 读取src目录下的所有txt文件，转换为大写后写入到dist目录
vfs.src('src/**/*.txt')
  .pipe(transformFile())
  .pipe(vfs.dest('dist'));

在这个示例中：
- vfs.src 方法读取 src 目录下的所有 .txt 文件，并将它们转换为 Vinyl 文件对象。
- transformFile 函数定义了一个流处理，接收文件并将其内容转换为大写。
- vfs.dest 方法将处理后的文件写入到 dist 目录中。

vinyl文件对象

gulp.src中这个流里的内容不是原始的文件流,而是一个虚拟文件对象流,这个虚拟文件对象中存储着原始文件的路径、文件名和内容等信息 vinyl
Vinyl 是一种虚拟文件格式，表示文件系统中的文件。它包含文件的路径、内容、状态等信息。vinyl-fs 使用 Vinyl 文件对象来抽象文件系统的操作，使得文件操作可以在流处理中完成。

var File = require('vinyl');
var indexFile = new File({
    cwd: "/",//当前路径
    base: "/test/",//文件名
    path: "/test/index.js",//路径
    contents: new Buffer("hs")//文件内容
});

console.log(File.isVinyl(indexFile));//是否是vinyl
console.log(indexFile.isBuffer());//内容是否是Buffer
console.log(indexFile.isStream());//内容是否是Stream

wrap-vinyl.js

through2内部仅是封装了Transform的构造函数

wrap-vinyl.js

var File = require('vinyl');
var through = require('through2');
function wrapVinyl() {
    function wrapFile(globFile, encoding, callback) {
        var file = new File(globFile);
        callback(null, file);
    }
    return through.obj(wrapFile);
}
module.exports = wrapVinyl;
let GlobStream = require('./glob-stream');
let wrapVinyl = require('./wrap-vinyl');
const glob = 'src/scripts/**/*.js';
let gs = new GlobStream(glob);
gs.pipe(wrapVinyl()).on('data', (data) => {
    console.log(data);
});

实现vinyl-fs

vinyl-fs\index.js

lib\vinyl-fs\index.js

const src = require('./lib/src');
const dest = require('./lib/dest');
module.exports = {
    src,
    dest
};

src\index.js

lib\vinyl-fs\lib\src\index.js

var gs = require('./glob-stream');
var readContents = require('./read-contents');
var wrapVinyl = require('./wrap-vinyl');
function src(glob) {
    let gsStream = gs(glob);
    let vinylStream = gsStream.pipe(wrapVinyl());
    let contentsStream = vinylStream.pipe(readContents());
    return contentsStream;
}
module.exports = src;

glob-stream.js

lib\vinyl-fs\lib\src\glob-stream.js

let { Readable } = require('readable-stream');
let { inherits } = require('util');
let { Glob } = require('glob');
var globParent = require('glob-parent');
var toAbsoluteGlob = require('to-absolute-glob');
inherits(GlobStream, Readable);
GlobStream.prototype._read = function () {
    this._globber.resume();
};
function globStream(glob, opt = {}) {
    opt.cwd = opt.cwd || process.cwd();
    return new GlobStream(glob, opt);
}
function GlobStream(glob, opt) {
    Readable.call(this, { objectMode: true });
    let absoluteGlob = toAbsoluteGlob(glob, opt);
    let basePath = globParent(absoluteGlob);
    let globber = new Glob(absoluteGlob, opt);
    this._globber = globber;
    globber.on('match', (filepath) => {
        let obj = {
            cwd: opt.cwd,
            base: basePath,
            path: filepath
        };
        this.push(obj)
    });
    globber.once('end', () => {
        this.push(null);
    });
}
module.exports = globStream;

read-contents.js

lib\vinyl-fs\lib\src\read-contents.js

let fs = require('fs');
let through = require('through2');
function readContents() {
    function readFile(file, encoding, callback) {
        fs.readFile(file.path, encoding, (err, data) => {
            file.contents = Buffer.from(data);
            callback(null, file);
        });
    }
    return through.obj(readFile);
}
module.exports = readContents;

wrap-vinyl.js

lib\vinyl-fs\lib\src\wrap-vinyl.js

var File = require('vinyl');
var through = require('through2');
function wrapVinyl() {
    function wrapFile(globFile, encoding, callback) {
        var file = new File(globFile);
        callback(null, file);
    }
    return through.obj(wrapFile);
}
module.exports = wrapVinyl;

dest\index.js

lib\vinyl-fs\lib\dest\index.js

const writeContents = require('./write-contents');
function dest(outFolder) {
    return writeContents(outFolder);
}
module.exports = dest;

write-contents.js

lib\vinyl-fs\lib\dest\write-contents.js

const fs = require('fs-extra');
const path = require('path');
var through = require('through2');
function writeContents(outFolder) {
    function writeFile(file, encoding, callback) {
        var basePath = path.resolve(file.cwd, outFolder);
        var writePath = path.resolve(basePath, file.relative);
        file.path = writePath;
        fs.ensureDir(path.dirname(writePath), (err) => {
            fs.writeFile(file.path, file.contents, encoding, callback);
        });
    }
    return through.obj(writeFile);
}
module.exports = writeContents;

实现插件

gulpfile.js

const { src, dest } = require('gulp4');
var gulpPrefixer = require('./gulp-prefixer');
var gulpBabel = require('./gulp-babel');
const defaultTask = () => {
    return src('src/scripts/**/*.js')
        .pipe(gulpPrefixer('/**prepended**/\n'))
        .pipe(gulpBabel({ presets: ["@babel/preset-env"] }))
        .pipe(dest('dist'));
}
exports.default = defaultTask;

gulp-prefixer.js

var through = require('through2');
function gulpPrefixer(prefixText) {
    prefixText = Buffer.from(prefixText);
    var stream = through.obj(function (file, enc, next) {
        if (file.isBuffer()) {
            file.contents = Buffer.concat([prefixText, file.contents]);
        }
        this.push(file);
        next();
    });
    return stream;
};
module.exports = gulpPrefixer;

gulp-babel.js

var through = require('through2');
const babel = require('@babel/core');
function gulpBabel(options) {
    var stream = through.obj(function (file, enc, next) {
        const { code } = babel.transformSync(file.contents, options);
        file.contents = Buffer.from(code);
        this.push(file);
        next();
    });
    return stream;
};
module.exports = gulpBabel;

gulp相关知识

gulp基础

什么是gulp

gulp特点

安装gulp

异步任务和组合任务

gulp核心API

gulp.src()

gulp.dest()

pipe

gulp实战

安装

编译样式

编译脚本

编译html

src\index.html

circle.svg

static\rect.svg

gulpfile.js

编译任务

压缩图片

安装

gulpfile.js

拷贝静态文件

删除输出目录

自动加载插件

开发服务器

gulpfile.js

6.10.2 main.js

监听文件变化

gulpfile.js

合并和压缩

src\index.html

gulpfile.js

glob相关

glob规则

glob示例

环节实现

实现gulp

安装依赖

gulpfile.js

package.json

bin\gulp4.js

bin\logEvents.js

bin\register-exports.js

lib\index.js

实现undertaker

npm使用示例

实现

lib\index.js

undertaker.js

使用流操作

gulpfile.js

vinyl-fs

vinyl-fs基础

glob

vinyl-fs介绍

vinyl文件对象

wrap-vinyl.js

实现vinyl-fs

vinyl-fs\index.js

src\index.js

glob-stream.js

read-contents.js

wrap-vinyl.js

dest\index.js

write-contents.js

实现插件

gulpfile.js

gulp-prefixer.js

gulp-babel.js