js随笔

• 格式化日期

new Date().toLocaleString('default', {hour12: false}).replace(/\b\d\b/g, '0$&')

• js代码 -> js字节码

const vm = require('vm');
const fs = require('fs');
const js_code = fs.readFileSync(__dirname+"/test.js").toString();
const script = new vm.Script(js_code, {produceCachedData: true});
const byte_code = script.cachedData;
fs.writeFileSync(__dirname+"/test.jsb",byte_code);

• js字节码 -> nodejs ->运行

const vm = require('vm');
const fs = require('fs');
const byte_code = fs.readFileSync(__dirname+"/test.jsb");
const len = byte_code.slice(8, 12).reduce((sum, number, power) => sum += number * Math.pow(256, power));
const dummyCode = ''.repeat(len);
script = new vm.Script(dummyCode, {cachedData: byte_code});
script.runInThisContext();