ast babeljs --2( 数组替换)

 

 

 

https://www.cnblogs.com/gaoyongjian/p/13246736.html

 

 

// 将js代码转换成AST
const { parse } = require("@babel/parser");
// 用来遍历AST中的节点
const traverse = require("@babel/traverse").default;
// AST转换成js
const generator = require("@babel/generator").default;
// 用来判断节点类型和生成新的节点
const t = require("@babel/types");
const fs = require("fs");

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

//some function code
const visitor =
{
    VariableDeclarator(path) {
        // 还原数组对象
        const { id, init } = path.node;
        // 非Array或者没有元素， 返回
        if (!t.isArrayExpression(init) || init.elements.length === 0) return;

        let elements = init.elements;

        // 获取binding实例
        const binding = path.scope.getBinding(id.name);

        for (const ref_path of binding.referencePaths) {
            // 获取 MemberExpression 父节点
            let member_path = ref_path.findParent(p => p.isMemberExpression());

            if (member_path == null) continue;
            let property = member_path.get('property');

            // 索引值不是 NumericLiteral 类型的不处理
            if (!property.isNumericLiteral()) {
                continue;
            }

            // 获取索引值
            let index = property.node.value;

            // 获取索引值对应的节点， 并替换
            let arr_ele = elements[index];
            member_path.replaceWith(arr_ele)
        }
    }
}


traverse(ast, visitor);

let code = generator(ast).code;

fs.writeFile('./demoNew.js', code, (err) => { });