babel学习

let obj = {
    name: 'lanqian',
    add: function(a, b){
        return a + b + 1000;
    },
    mul: function(a, b){
        return a * b + 1000;
    }
}

const fs = require('fs');
const parser = require("E:/nodejs/npm_global_modules/node_modules/@babel/parser")
const traverse = require("E:/nodejs/npm_global_modules/node_modules/@babel/traverse").default
const t = require("E:/nodejs/npm_global_modules/node_modules/@babel/types")
const generator = require("E:/nodejs/npm_global_modules/node_modules/@babel/generator").default

const jscode = fs.readFileSync("./demo.js", {encoding: "utf-8"});
let ast = parser.parse(jscode)

//ast操作
// let code = generator(ast).code
// console.log(ast)

//遍历节点，替换参数
const updateParamNameVisitor = {
    Identifier(path){
        if (path.node.name == this.paramName){
            path.node.name = "x"
        }
    }
}
const visitor = {
    FunctionExpression(path){
        const paramName = path.node.params[0].name;
        path.traverse(updateParamNameVisitor, {
            paramName
        });
    }
}
traverse(ast, visitor)
//语法树转成代码
let code = generator(ast).code
console.log(code)
// fs.writeFile('./demoNew.js', code, (err) =>{})