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https://github.com/shuerguo999/gogoAST
The simplest tool to parse/transform/generate code on ast
https://github.com/shuerguo999/gogoAST
acorn ast ast-types astquery asttool babel babel-generator babel-parser babel-traverse babel-types babylon easyast esprima htmlparser jscodeshift mustache recast simpleast
Last synced: 3 months ago
JSON representation
The simplest tool to parse/transform/generate code on ast
- Host: GitHub
- URL: https://github.com/shuerguo999/gogoAST
- Owner: shuerguo999
- License: other
- Created: 2020-03-03T16:21:16.000Z (almost 5 years ago)
- Default Branch: master
- Last Pushed: 2021-01-24T17:51:40.000Z (about 4 years ago)
- Last Synced: 2024-10-20T23:15:48.754Z (3 months ago)
- Topics: acorn, ast, ast-types, astquery, asttool, babel, babel-generator, babel-parser, babel-traverse, babel-types, babylon, easyast, esprima, htmlparser, jscodeshift, mustache, recast, simpleast
- Language: JavaScript
- Size: 473 KB
- Stars: 31
- Watchers: 3
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
- awesome-github-star - gogoAST
README
# GOGOAST
全网最简单易上手，可读性最强的AST处理工具！
# Install
- node包安装
```
npm install gogoast
```
- 浏览器执行
> commonjs引入gogoast.js
# 为什么你需要用gogoAST？
- 大幅减少代码量——如果你需要使用AST对代码进行升级、改造、分析，快用gogoAST帮你摆脱繁琐冗余的的代码，专注于你的核心逻辑。不需要traverse，像剥洋葱一样一层一层的对比、操作、构造ast节点。
- 降低理解成本——甚至不需要理解什么是CallExpression、Identifier、ImportDeclaration这些概念，就可以畅快运用AST。
- 基于recast，转换后的代码基本与源代码的格式差异最小。
- 凡是需要借助babel、recast、jscodeshift、esprima...完成的需求，gogoast都能帮你更快更简单的完成。
# 快速开始
- 创建一个AST对象
``` javascript
const code = `some code`
const GG = require('gogoast');
const AST = GG.createAstObj(code);
```
- 查找代码片段
用一段包含通配符（$_$）的'代码选择器'来查找相应的代码片段，如：
- 查找代码中所有的变量
``` javascript
const { matchWildCardList } = AST.getAstsBySelector(`$_$`);
```
- 查找代码中所有的字符串
``` javascript
const { matchWildCardList } = AST.getAstsBySelector(`'$_$'`);
```
- 查找某些函数的调用
``` javascript
const { nodePathList, matchWildCardList } = AST.getAstsBySelector([
'$_$.setTip($_$, $_$)',
'tip.show($_$)'
]);
```
- 选择器示例：
``` javascript
var $_$ = $_$
function $_$ () { $_$ }
View.extend($_$)
$_$ ? $_$ : $_$
$_$ && $_$
```
返回结果 |nodePathList | matchWildCardList|
-- |-- | :--:
描述|代码选择器匹配到的代码片段 | 代码选择器中通配符匹配到的代码片段
结构|nodePath[]|{ stucture: node, value: simpleNode }[]
解释|nodePath对象包含匹配到的ast结构及其上下文| structure中的node是ast结构，value是简化后的node，便于取值
- 替换一段代码
1. 在完整的AST片段中，通过param1查找对应的代码片段
2. 通过param2生成一段代码，填入param1中通配符对应的代码
3. 将param2生成的代码替换param1匹配的代码
```javascript
AST.replaceSelBySel(param1, param2);
AST.replaceSelBySel('const $_$ = require($_$)', 'import $_$ from $_$');
```
# gogoAST与主流AST工具之对比
目前，自定义babel插件和jscodeshift是有代表性的AST工具，通过下面两个例子可以看出gogoAST的代码可读性和简洁的优势。
- 示例1: 与自定义babel插件对比
对于下面这段js代码
```javascript
import a from 'a';
console.log('get A')
var b = console.log()
console.log.bind()
var c = console.log
console.log = func
```
假如我们希望对不同的console.log做不同的处理，变成下面这样
```
import a from 'a';
var b = void 0;
console.log.bind()
var c = function(){};
console.log = func
```
- 用自定义Babel插件实现的核心代码：
```javascript
// 代码来源：https://zhuanlan.zhihu.com/p/32189701
module.exports = function({ types: t }) {
return {
name: "transform-remove-console",
visitor: {
CallExpression(path, state) {
const callee = path.get("callee");
if (!callee.isMemberExpression()) return;
if (isIncludedConsole(callee, state.opts.exclude)) {
// console.log()
if (path.parentPath.isExpressionStatement()) {
path.remove();
} else {
//var a = console.log()
path.replaceWith(createVoid0());
}
} else if (isIncludedConsoleBind(callee, state.opts.exclude)) {
// console.log.bind()
path.replaceWith(createNoop());
}
},
MemberExpression: {
exit(path, state) {
if (
isIncludedConsole(path, state.opts.exclude) &&
!path.parentPath.isMemberExpression()
) {
//console.log = func
if (
path.parentPath.isAssignmentExpression() &&
path.parentKey === "left"
) {
path.parentPath.get("right").replaceWith(createNoop());
} else {
//var a = console.log
path.replaceWith(createNoop());
}
}
}
}
}
};
```
- 用gogoAST实现：
```javascript
const AST = GG.createAstObj(code);
AST.replaceSelBySel(`var $_$ = console.log()`, `$_$ = void 0`);
AST.replaceSelBySel(`console.log()`, null);
AST.replaceSelBySel(`var $_$ = console.log`, `$_$ = function(){}`);
const result = AST.generate();
```
- 示例2: 与jscodeshift对比
对于下面这段代码：
```javascript
import car from 'car';
const suv = car.factory('white', 'Kia', 'Sorento', 2010, 50000, null, true);
const truck = car.factory('silver', 'Toyota', 'Tacoma', 2006, 100000, true, true);
```
假如我们希望将函数的多个入参封装为一个对象传入，变成下面这样
```javascript
import car from 'car';
const suv = car.factory({"color":"white","make":"Kia","model":"Sorento","year":2010,"miles":50000,"bedliner":null,"alarm":true});
const truck = car.factory({"color":"silver","make":"Toyota","model":"Tacoma","year":2006,"miles":100000,"bedliner":true,"alarm":true});
```
- 用jscodeshift实现的核心代码：
``` javascript
// 代码来源：https://www.toptal.com/javascript/write-code-to-rewrite-your-code
export default (fileInfo, api) => {
const j = api.jscodeshift;
const root = j(fileInfo.source);
// find declaration for "car" import
const importDeclaration = root.find(j.ImportDeclaration, {
source: {
type: 'Literal',
value: 'car',
},
});
// get the local name for the imported module
const localName =
importDeclaration.find(j.Identifier)
.get(0)
.node.name;
// current order of arguments
const argKeys = [
'color',
'make',
'model',
'year',
'miles',
'bedliner',
'alarm',
];
// find where `.factory` is being called
return root.find(j.CallExpression, {
callee: {
type: 'MemberExpression',
object: {
name: localName,
},
property: {
name: 'factory',
},
}
})
.replaceWith(nodePath => {
const { node } = nodePath;
// use a builder to create the ObjectExpression
const argumentsAsObject = j.objectExpression(
// map the arguments to an Array of Property Nodes
node.arguments.map((arg, i) =>
j.property(
'init',
j.identifier(argKeys[i]),
j.literal(arg.value)
)
)
);
// replace the arguments with our new ObjectExpression
node.arguments = [argumentsAsObject];
return node;
})
// specify print options for recast
.toSource({ quote: 'single', trailingComma: true });
};
```
- 用gogoAST实现：
``` javascript
const AST = GG.createAstObj(code);
const argKeys = ['color', 'make', 'model', 'year', 'miles', 'bedliner', 'alarm' ];
const { nodePathList, matchWildCardList } = AST.getAstsBySelector(`const $_$ = car.factory($_$)`, 'nn', false);
nodePathList.forEach((path, i) => {
const extra = matchWildCardList[i];
const variableName = extra.shift().value;
const obj = {};
extra.forEach((ext, ei) => {
obj[argKeys[ei]] = ext.structure.value
});
const newCall = GG.buildAstByAstStr(`${variableName} = car.factory(${JSON.stringify(obj)})`)
AST.replaceAstByAst(path, newCall);
})
const result = AST.generate();
```
# API
陆续补充中
1. 创建一个实例：createAstObj
```javascript
const GG = require('gogoast');
const AST = GG.createAstObj(p, options);
// options非必传，格式同babel-parse,如 { allowImportExportEverywhere: true, plugins: ['jsx'] }
```
2. 通过选择器查找AST节点：getAstsBySelector
- 选择器是一段包含通配符（$_$）的代码
- nodePathList：返回找到的ast节点路径，包含自己节点、父节点等信息
- matchWildCardList：返回通配符$_$代表的节点信息，其中structure是节点完整信息，value是简略信息
```javascript
const { nodePathList, matchWildCardList } = AST.getAstsBySelector([
'$_$.setTip($_$, $_$)',
'tip.show($_$)'
]);
```
3. 通过选择器替换另一个选择器查找到的AST节点：replaceSelBySel
- 就像'abcd'.replace('a', 'z')一样好用
```javascript
AST.replaceSelBySel('const $_$ = require($_$)', 'import $_$ from $_$');
AST.replaceSelBySel('$.extend(true, $_$, $_$)', 'Object.assign($_$, $_$)');
AST.replaceSelBySel('$.each($_$, function($_$, $_$) { $_$ } )', '$_$.forEach($_$, $_$)');
```
4. 创建一个AST节点：buildAstByAstStr
- 可以通过字符串拼接AST节点的方式构造新的AST节点
```javascript
const type = 'error';
const content = ASTNODE; // 从其他代码中提取出来或者自己构造的ast节点
GG.buildAstByAstStr(`
Alert.show({
type: '${type}',
content: '$_$content$_$'
})
`, {
content
})
```
5. GG模块其他基本方法
- 将AST节点转成字符串 generate(ast)
- 获取AST节点的所有父节点 getParentListByAst(path)
- 判断一个AST节点是否包含某子节点，子节点用选择器表示 hasChildrenSelector(path, childSelector)
- 用一个AST节点替换某个字符串 replaceStrByAst
- replaceAstByAst
- getPrevAst
- getNextAst
- insertAstListBefore
- insertAstListAfter
- removeAst
- ......
- AST实例上也有部分方法，用法相比GG模块调用少传第一个参数，实际传入的是该实例自身的ast结构
6. 特殊类型AST节点的构造方法
- buildObjectProperty
```javascript
// 为什么不直接用buildAstByAstStr？把一个对象粘贴进astexplore就知道了
AST.buildObjectProperty({
url: 'getList',
type: 'get'
})
```
- appendJsxAttr
```javascript
const locaid = '98s8dh3';
const params = [ 'a=${aa}', 'b=${{aaa:"222",xxx:{ssss:111}}}', 'c=${"s"}', 'd=${a+1}','e=${ ss?2:1}' ]
AST.appendJsxAttr({
'attr1: `{${'`'}gostr='$'{gostr};locaid=d${locaid};${params.join('&')}}${'`'}}`, // 模板字符串
a: `{a+1}`, // 表达式
b: `'a'`, // 字符串
c: `{a}` // 变量
});
// 结果：
```
# 使用示例（陆续补充）
1. 将一段代码最外层所有未export的变量定义都加上export
``` javascript
const GG = require('gogoast');
const AST = GG.createAstObj(code); // code是源代码字符串
const { nodePathList } = AST.getAstsBySelector(`const $_$ = $_$`, true, 'n'); // 匹配到最外层的变量定义
nodePathList.forEach(p => {
if (p.parent.node.type == 'ExportNamedDeclaration') { // declarator类型的节点肯定至少存在两级parent，不会报错
return; // 已经export的不处理
}
GG.replaceAstByAst(p, { type: 'ExportNamedDeclaration', declaration: p.value })
})
console.log(AST.generate()) // 输出代码
```