feat: gogocode-plugin-optional-chaining

packages/gogocode-plugin-optional-chaining/README.md

@@ -0,0 +1,27 @@
+作为 npm 包，项目根目录的 transform.js 会被 gogocode-cli 调用
+
+fileInfo 会包括 source 和 path 作为单个代码文件的内容和路径
+api 目前只有 gogocode 作为转换库注入
+options 将透传命令行的 options
+
+```javascript
+
+module.exports = function(fileInfo, api, options) {
+  const sourceCode = fileInfo.source;
+  const $ = api.gogocode;
+  return $(sourceCode)
+    .replace('const a = $_$', 'const a = 2')
+    .generate();
+};
+
+```
+
+命令行调用方式：
+
+
+```
+
+gogogcode --src script.js --out script-compiled.js --transform=transform.js
+
+
+```

packages/gogocode-plugin-optional-chaining/package.json

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+{
+  "name": "gogocode-plugin-optional-chaining",
+  "version": "0.0.1",
+  "description": "gogocode-plugin-optional-chaining",
+  "scripts": {
+    "start": "node ./test/run.js"
+  },
+  "keywords": [
+    "gogocode",
+    "ast"
+  ],
+  "main": "transform.js",
+  "author": "chibing",
+  "license": "ISC",
+  "engines": {
+    "node": "*"
+  },
+  "devDependencies": {
+    "gogocode": "^1.0.48"
+  }
+}

packages/gogocode-plugin-optional-chaining/test/input.js

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+const a = x?.b?.c;
+
+const t = x?.[0]?.[1];
+
+const f = x?.['name']?.[1];
+
+const g = x?.["s"];

packages/gogocode-plugin-optional-chaining/test/run.js

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+const $ = require('gogocode');
+const t = require('../transform');
+const path = require('path');
+const fs = require('fs');
+
+const inputPath = path.resolve(__dirname, './input.vue');
+const outputPath = path.resolve(__dirname, './output.vue');
+
+fs.readFile(inputPath, function read(err, code) {
+    if (err) {
+        throw err;
+    }
+    const outputCode = t(
+        {
+            source: code.toString(),
+            path: inputPath
+        },
+        {
+            gogocode: $
+        },
+        {
+            rootPath: __dirname,
+            outFilePath: outputPath,
+            outRootPath: __dirname,
+        }
+    );
+
+    fs.writeFile(outputPath, outputCode, function (err) {
+        if (err) {
+            throw err;
+        }
+        console.log('The file was saved!');
+    });
+});

packages/gogocode-plugin-optional-chaining/transform.js

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+/**
+ * 转换入口导出一个函数，按照如下函数签名
+ * @param {*} fileInfo 包含 source 和 path 属性
+ * @param {*} api 包含 gogocode 作为转换工具
+ * @param {*} options 其他 option 由此传入
+ * @returns {string} 返回转换后的代码
+ */
+module.exports = function (fileInfo, api, options) {
+    const $ = api.gogocode
+    const source = fileInfo.source
+    const ast = $(source)
+
+    const opt = ast.find(
+        {type: 'OptionalMemberExpression'}
+    )
+
+    if(!opt.length) {
+        return ast.generate();
+    }
+
+    if(!ast.has([`const _ = require('lodash')`, `import _ from 'lodash'`])) {
+        ast.prepend(`const _ = require('lodash')\n\n`)
+    }
+
+    function toNormalChain(optAst) {
+        const property = optAst.attr('property')
+        const object = optAst.attr('object')
+        let str = $(property).generate()
+
+        if (property.type === 'StringLiteral' || property.type === 'NumericLiteral') {
+            str = `[${str}]`
+        } else {
+            str = `.${str}`
+        }
+
+        if(object.type === 'MemberExpression' || object.type === 'OptionalMemberExpression') {
+            const res = toNormalChain($(object))
+            return {
+                object: res.object,
+                path: `${res.path}${str}`
+            }
+        } else {
+            return {
+                object: $(object).generate(),
+                path: str.replace(/^\./, '')
+            }
+        }
+    }
+
+    opt.each(item => { 
+        if(item.parent()?.node?.type !== 'OptionalMemberExpression') {
+            const { object, path } = toNormalChain(item)
+            item.replaceBy(`_.get(${object}, \`${path}\`)`)
+        }
+    })
+
+    // return your transformed code here
+    return ast.generate()
+};