组合模式

const MacroCommand = function() {
    this.lists = [] // 宏任务维护一个任务列表
}
MacroCommand.prototype.add = function(task) {
    this.lists.push(task) // add 方法增加任务
}
MacroCommand.prototype.execute = function() {
    for (let index = 0; index < this.lists.length; index++) {
        this.lists[index].execute() // execute 方法执行任务
    }
}

const command1 = new MacroCommand() // 通过 new 操作符创建任务

command1.add({
    execute: () => { console.log('command1-1') }
})

command1.add({
    execute: () => { console.log('command1-2') }
})

const command2 = new MacroCommand()

command2.add({
    execute: () => { console.log('command2-1') }
})

command2.add({
    execute: () => { console.log('command2-2') }
})

command2.add({
    execute: () => { console.log('command2-3') }
})

const macroCommand = new MacroCommand() // 假定 macroCommand 为宏任务

macroCommand.add(command1) // 将其他子任务推如任务列表
macroCommand.add(command2)

macroCommand.execute() // 宏命令执行操作后，command 将依次递归执行
// command1-1
// command1-2
// command2-1
// command2-2
// command2-3

const Folder = function(folder) {
    this.folder = folder
    this.lists = []
}
Folder.prototype.add = function(res) {
    this.lists.push(res)
}
Folder.prototype.scan = function() {
    console.log(`开始扫描文件夹: ${this.folder}`)
    for (let index = 0; index < this.lists.length; index++) {
        this.lists[index].scan()
    }
}

const File = function(file) {
    this.file = file 
}
File.prototype.add = function() {
    throw Error('文件中不可添加文件')
}
File.prototype.scan = function() {
    console.log(`开始扫描文件: ${this.file}`)
}

const folder = new Folder('根文件夹')
const folder1 = new Folder('JS')
const folder2 = new Folder('其他')

const file = new File('JS prototype')
const file1 = new File('CSS 编程艺术')
const file2 = new File('HTML 标记语言')
const file3 = new File('HTTP-TCP-IP')

folder.add(folder1)
folder.add(folder2)

folder1.add(file)
folder2.add(file1)
folder2.add(file2)
folder2.add(file3)

folder.scan()

// 开始扫描文件夹: 根文件夹
// 开始扫描文件夹: JS
// 开始扫描文件: JS prototype
// 开始扫描文件夹: 其他
// 开始扫描文件: CSS 编程艺术
// 开始扫描文件: HTML 标记语言
// 开始扫描文件: HTTP-TCP-IP