@ainc/script/src/script.ts

Script compiler for typescript

/**
 *****************************************
 * Created by edonet@163.com
 * Created on 2020-05-21 14:03:13
 *****************************************
 */
'use strict';


/**
 *****************************************
 * 加载依赖
 *****************************************
 */
import * as path from 'path';
import * as vm from './vm';
import { watch, Watcher } from './watcher';


/**
 *****************************************
 * 执行文件接口
 *****************************************
 */
export function invoke(file: string, args: unknown[] = [], context: unknown = null): unknown {
    const script = execute(file);

    // 处理函数
    if (typeof script === 'function') {
        return script.apply(context, args);
    }

    // 处理默认函数
    if (script && typeof script === 'object') {
        const { default: handler } = script as { default?(...args: any[]): unknown };

        // 执行默认函数
        if (typeof handler === 'function') {
            return handler.apply(context, args);
        }
    }
}


/**
 *****************************************
 * 执行代码
 *****************************************
 */
export function run<T>(code: string, filename = '_script.js'): T {
    if (code && typeof code === 'string') {
        return vm.load<T>(path.resolve(filename), code).exports;
    }

    // 返回空对象
    return {} as T;
}


/**
 *****************************************
 * 执行文件
 *****************************************
 */
export function execute<T>(filename: string, context = process.cwd()): T {
    return run<T>(
        `module.exports = require(${JSON.stringify(path.resolve(context, filename))});`
    );
}


/**
 *****************************************
 * 脚本
 *****************************************
 */
export class Script<T> {

    /** 脚本对象 */
    private $script?: vm.Script;

    /** 文件列表 */
    public get files(): string[] {
        return this.$script ? vm.findDependencies(this.$script) : [];
    }

    /** 抛出接口 */
    public get exports(): T {
        return (this.$script ? this.$script.exports : {}) as T;
    }

    /** 脚本目录 */
    public get dirname(): string {
        return path.dirname(this.filename);
    }

    /** 脚本文件 */
    public get filename(): string {
        return this.$script ? this.$script.filename : path.resolve('_script.js');
    }

    /** 执行文件 */
    public execute(filename: string, context = process.cwd()): T {
        return this.run(
            `module.exports = require(${JSON.stringify(path.resolve(context, filename))});`
        );
    }

    /** 执行代码 */
    public run(code: string, filename = '_script.js'): T {

        // 校验参数
        if (typeof code !== 'string') {
            throw new Error('expect `code` to be string!');
        }

        // 生成脚本
        const script = vm.load<T>(path.resolve(filename), code);

        // 缓存脚本对象
        Object.defineProperty(this, '$script', {
            value: script,
            enumerable: false,
            configurable: true,
        });

        // 返回结果
        return script.exports;
    }

    /** 重载模块 */
    public reload(files?: string[]): T {

        // 不存在脚本文件
        if (!this.$script) {
            return {} as T;
        }

        // 获取代码
        const code = this.$script._code || '';
        const filename = this.$script.filename;

        // 刷新依赖文件
        vm.refresh(this.$script, files || []);

        // 执行模块
        return this.run(code, filename);
    }

    /** 监听模块变更 */
    public watch(callback: (data: T) => void): Watcher {
        const watcher = watch(this.files);

        // 监听文件变更
        watcher.on('change', (file: string) => {
            const deps = new Set(this.files);

            // 执行回调
            callback(this.reload([file]));

            // 添加依赖
            this.files.forEach(file => {
                deps.has(file) ? deps.delete(file) : watcher.add(file);
            });

            // 清除依赖
            deps.forEach(file => watcher.unwatch(vm.clear(file)));
        });

        // 返回监听器
        return watcher;
    }
}


/**
 *****************************************
 * 抛出接口
 *****************************************
 */
export default Script;