AST操作之API用法-path路径

AST抽象语法树/5.AST操作之API用法-path路径/README.md

@@ -227,3 +227,42 @@ var a;
 ```
 
 **替换path，单路径可以使用`replaceWith`方法，多路径则使用`replaceWithMultiple`方法**
+
+需求：把var a = 123; 修改成var a =  3 ，用replaceWith方法
+
+```javascript
+const fs = require('fs');
+const {parse} = require("@babel/parser");
+const traverse = require("@babel/traverse").default;
+const generator = require("@babel/generator").default;
+let encode_file = "./encode.js";
+
+let js_code = fs.readFileSync(encode_file, {encoding: "utf-8"});
+let ast = parse(js_code, {
+    sourceType: 'module',
+});
+
+const visitor = {
+    enter(path) {
+        if (path.isNumericLiteral() && path.node.value == 123) {
+            path.replaceWith({type: "NumericLiteral", value: 3});
+        }
+    },
+}
+
+traverse(ast, visitor);
+
+// 写入文件
+let {code} = generator(ast);
+console.log(code)
+fs.writeFile('decode.js', code, (err) => {
+});
+```
+
+打印内容：
+
+```javascript
+var a = 3;
+```
+
+注意点，必须加上`&& path.node.value == 123`判断，否则就是无限循环

AST抽象语法树/5.AST操作之API用法-path路径/decode_obfuscator.js

@@ -11,8 +11,8 @@ let ast = parse(js_code, {
 
 const visitor = {
     enter(path) {
-        if (path.isNumericLiteral()) {
-            path.replaceWith({type:"NumericLiteral",value:3});
+        if (path.isNumericLiteral() && path.node.value == 123) {
+            path.replaceWith({type: "NumericLiteral", value: 3});
         }
     },
 }