@ainc/script/src/watcher.ts

Script compiler for typescript

/**
 *****************************************
 * Created by edonet@163.com
 * Created on 2021-06-27 16:00:15
 *****************************************
 */
'use strict';


/**
 *****************************************
 * 加载依赖
 *****************************************
 */
import { Stats } from 'fs';
import * as chokidar from 'chokidar';


/**
 *****************************************
 * 监听对象
 *****************************************
 */
export interface Watcher extends chokidar.FSWatcher {
    waitExit(): Promise<void>;
}


/**
 *****************************************
 * 监听回调
 *****************************************
 */
export interface Handler {
    (this: Watcher, type: 'add'|'addDir'|'change'|'unlink'|'unlinkDir', path: string, stats?: Stats): void;
}


/**
 *****************************************
 * 配置
 *****************************************
 */
export interface Options extends chokidar.WatchOptions {
    handler?: Handler;
}


/**
 *****************************************
 * 监听文件文件变更
 *****************************************
 */
export function watch(files: string | string[], handler?: Handler | Options): Watcher {
    const opts = typeof handler === 'function' ? { handler } : { ...handler };
    const watcher = chokidar.watch(files, opts) as Watcher;
    const closeWatcher = watcher.close.bind(watcher);

    // 监听变更
    if (typeof opts.handler === 'function') {
        watcher.on('all', opts.handler.bind(watcher));
    }

    // 替换关闭函数
    watcher.close = () => {
        const deferred = {} as { resolve(): void, reject(): void };

        // 执行关闭事件
        watcher.emit('close', new Promise(
            (resolve, reject) => Object.assign(deferred, { resolve, reject })
        ));

        // 执行关闭
        return closeWatcher().then(deferred.resolve, deferred.reject);
    };

    // 等待结束
    watcher.waitExit = () => {
        return new Promise(resolve => watcher.once('close', resolve));
    };

    // 返回监听对象
    return watcher;
}