// 示例 async function fn() {   let value = await new Promise((resolve, reject) => {     reject('failure');   });   console.log('do something...'); } fn()

async function fn() {   await new Promise((resolve, reject) => reject('報(bào)錯(cuò)'));   await new Promise((resolve) => resolve(1));   console.log('do something...'); } fn();

async function fn() {   try {     await new Promise((resolve, reject) => reject('報(bào)錯(cuò)'));     await new Promise(resolve => resolve(1));     console.log('do something...');   } catch (e) {     console.log("nfilePath: E:\myapp\src\main.jsnfuncName: fnnError:", e);   } } fn();

function demo(n) {   return n * n; }

{   "type": "Program", // 整段代碼的主體   "body": [     {       "type": "FunctionDeclaration", // function 的類(lèi)型叫函數(shù)聲明；       "id": { // id 為函數(shù)聲明的 id         "type": "Identifier", // 標(biāo)識(shí)符 類(lèi)型         "name": "demo" // 標(biāo)識(shí)符 具有名字        },       "expression": false,       "generator": false,       "async": false, // 代表是否 是 async function       "params": [ // 同級(jí) 函數(shù)的參數(shù)          {           "type": "Identifier",// 參數(shù)類(lèi)型也是 Identifier           "name": "n"         }       ],       "body": { // 函數(shù)體內(nèi)容 整個(gè)格式呈現(xiàn)一種樹(shù)的格式         "type": "BlockStatement", // 整個(gè)函數(shù)體內(nèi)容 為一個(gè)塊狀代碼塊類(lèi)型         "body": [           {             "type": "ReturnStatement", // return 類(lèi)型             "argument": {               "type": "BinaryExpression",// BinaryExpression 二進(jìn)制表達(dá)式類(lèi)型               "start": 30,               "end": 35,               "left": { // 分左 右 中 結(jié)構(gòu)                 "type": "Identifier",                  "name": "n"               },               "operator": "*", // 屬于操作符               "right": {                 "type": "Identifier",                 "name": "n"               }             }           }         ]       }     }   ],   "sourceType": "module" }

async function fn() {    await f() }

async function fn() {     try {         await f()     } catch (e) {         console.log(e)     } }

module.exports = function (babel) {    let t = babel.type    return {       visitor: {        // 設(shè)置需要范圍的節(jié)點(diǎn)類(lèi)型        CallExression: (path, state) => {           do soming ……        }      }    }  }

module.exports = function (babel) {    let t = babel.type    return {       visitor: {        // 設(shè)置AwaitExpression        AwaitExpression(path) {          // 獲取當(dāng)前的await節(jié)點(diǎn)          let node = path.node;        }      }    }  }

// async節(jié)點(diǎn)的屬性為true const asyncPath = path.findParent(p => p.node.async)

// 1️⃣：函數(shù)聲明 async function fn() {   await f() }  // 2️⃣：函數(shù)表達(dá)式 const fn = async function () {   await f() };  // 3️⃣：箭頭函數(shù) const fn = async () => {   await f() };  // 4️⃣：async函數(shù)定義在對(duì)象中 const obj = {   async fn() {       await f()   } }

module.exports = function (babel) {    let t = babel.type    return {       visitor: {        // 設(shè)置AwaitExpression        AwaitExpression(path) {          // 獲取當(dāng)前的await節(jié)點(diǎn)          let node = path.node;          // 查找async函數(shù)的節(jié)點(diǎn)          const asyncPath = path.findParent((p) => p.node.async && (p.isFunctionDeclaration() || p.isArrowFunctionExpression() || p.isFunctionExpression() || p.isObjectMethod()));        }      }    }  }

// 引入babel-template const template = require('babel-template');  // 定義try/catch語(yǔ)句模板 let tryTemplate = ` try { } catch (e) { console.log(CatchError：e) }`;  // 創(chuàng)建模板 const temp = template(tryTemplate);  // 給模版增加key，添加console.log打印信息 let tempArgumentObj = {    // 通過(guò)types.stringLiteral創(chuàng)建字符串字面量    CatchError: types.stringLiteral('Error') };  // 通過(guò)temp創(chuàng)建try語(yǔ)句的AST節(jié)點(diǎn) let tryNode = temp(tempArgumentObj);

module.exports = function (babel) {    let t = babel.type    return {       visitor: {        AwaitExpression(path) {          let node = path.node;          const asyncPath = path.findParent((p) => p.node.async && (p.isFunctionDeclaration() || p.isArrowFunctionExpression() || p.isFunctionExpression() || p.isObjectMethod()));                    let tryNode = temp(tempArgumentObj);                    // 獲取父節(jié)點(diǎn)的函數(shù)體body          let info = asyncPath.node.body;           // 將函數(shù)體放到try語(yǔ)句的body中          tryNode.block.body.push(...info.body);           // 將父節(jié)點(diǎn)的body替換成新創(chuàng)建的try語(yǔ)句          info.body = [tryNode];        }      }    }  }

// 示例代碼，不再添加try/catch async function fn() {     try {         await f()     } catch (e) {         console.log(e)     } }

module.exports = function (babel) {    let t = babel.type    return {       visitor: {        AwaitExpression(path) {                 // 判斷父路徑中是否已存在try語(yǔ)句，若存在直接返回         if (path.findParent((p) => p.isTryStatement())) {           return false;         }                  let node = path.node;          const asyncPath = path.findParent((p) => p.node.async && (p.isFunctionDeclaration() || p.isArrowFunctionExpression() || p.isFunctionExpression() || p.isObjectMethod()));          let tryNode = temp(tempArgumentObj);          let info = asyncPath.node.body;          tryNode.block.body.push(...info.body);          info.body = [tryNode];        }      }    }  }

// 獲取編譯目標(biāo)文件的路徑，如：E:myappsrcApp.vue const filePath = this.filename || this.file.opts.filename || 'unknown';

// 定義方法名 let asyncName = '';  // 獲取async節(jié)點(diǎn)的type類(lèi)型 let type = asyncPath.node.type;  switch (type) { // 1️⃣函數(shù)表達(dá)式 // 情況1：普通函數(shù)，如const func = async function () {} // 情況2：箭頭函數(shù)，如const func = async () => {} case 'FunctionExpression': case 'ArrowFunctionExpression':   // 使用path.getSibling(index)來(lái)獲得同級(jí)的id路徑   let identifier = asyncPath.getSibling('id');   // 獲取func方法名   asyncName = identifier && identifier.node ? identifier.node.name : '';   break;  // 2️⃣函數(shù)聲明，如async function fn2() {} case 'FunctionDeclaration':   asyncName = (asyncPath.node.id && asyncPath.node.id.name) || '';   break;  // 3️⃣async函數(shù)作為對(duì)象的方法，如vue項(xiàng)目中，在methods中定義的方法: methods: { async func() {} } case 'ObjectMethod':   asyncName = asyncPath.node.key.name || '';   break; }  // 若asyncName不存在，通過(guò)argument.callee獲取當(dāng)前執(zhí)行函數(shù)的name let funcName = asyncName || (node.argument.callee && node.argument.callee.name) || '';

// babel-template 用于將字符串形式的代碼來(lái)構(gòu)建AST樹(shù)節(jié)點(diǎn) const template = require('babel-template');  const { tryTemplate, catchConsole, mergeOptions, matchesFile } = require('./util');  module.exports = function (babel) {   // 通過(guò)babel 拿到 types 對(duì)象，操作 AST 節(jié)點(diǎn)，比如創(chuàng)建、校驗(yàn)、轉(zhuǎn)變等   let types = babel.types;    // visitor：插件核心對(duì)象，定義了插件的工作流程，屬于訪問(wèn)者模式   const visitor = {     AwaitExpression(path) {       // 通過(guò)this.opts 獲取用戶(hù)的配置       if (this.opts && !typeof this.opts === 'object') {         return console.error('[babel-plugin-await-add-trycatch]: options need to be an object.');       }        // 判斷父路徑中是否已存在try語(yǔ)句，若存在直接返回       if (path.findParent((p) => p.isTryStatement())) {         return false;       }        // 合并插件的選項(xiàng)       const options = mergeOptions(this.opts);        // 獲取編譯目標(biāo)文件的路徑，如：E:myappsrcApp.vue       const filePath = this.filename || this.file.opts.filename || 'unknown';        // 在排除列表的文件不編譯       if (matchesFile(options.exclude, filePath)) {         return;       }        // 如果設(shè)置了include，只編譯include中的文件       if (options.include.length && !matchesFile(options.include, filePath)) {         return;       }        // 獲取當(dāng)前的await節(jié)點(diǎn)       let node = path.node;        // 在父路徑節(jié)點(diǎn)中查找聲明 async 函數(shù)的節(jié)點(diǎn)       // async 函數(shù)分為4種情況：函數(shù)聲明 || 箭頭函數(shù) || 函數(shù)表達(dá)式 || 對(duì)象的方法       const asyncPath = path.findParent((p) => p.node.async && (p.isFunctionDeclaration() || p.isArrowFunctionExpression() || p.isFunctionExpression() || p.isObjectMethod()));        // 獲取async的方法名       let asyncName = '';        let type = asyncPath.node.type;        switch (type) {         // 1️⃣函數(shù)表達(dá)式         // 情況1：普通函數(shù)，如const func = async function () {}         // 情況2：箭頭函數(shù)，如const func = async () => {}         case 'FunctionExpression':         case 'ArrowFunctionExpression':           // 使用path.getSibling(index)來(lái)獲得同級(jí)的id路徑           let identifier = asyncPath.getSibling('id');           // 獲取func方法名           asyncName = identifier && identifier.node ? identifier.node.name : '';           break;          // 2️⃣函數(shù)聲明，如async function fn2() {}         case 'FunctionDeclaration':           asyncName = (asyncPath.node.id && asyncPath.node.id.name) || '';           break;          // 3️⃣async函數(shù)作為對(duì)象的方法，如vue項(xiàng)目中，在methods中定義的方法: methods: { async func() {} }         case 'ObjectMethod':           asyncName = asyncPath.node.key.name || '';           break;       }        // 若asyncName不存在，通過(guò)argument.callee獲取當(dāng)前執(zhí)行函數(shù)的name       let funcName = asyncName || (node.argument.callee && node.argument.callee.name) || '';        const temp = template(tryTemplate);        // 給模版增加key，添加console.log打印信息       let tempArgumentObj = {         // 通過(guò)types.stringLiteral創(chuàng)建字符串字面量         CatchError: types.stringLiteral(catchConsole(filePath, funcName, options.customLog))       };        // 通過(guò)temp創(chuàng)建try語(yǔ)句       let tryNode = temp(tempArgumentObj);        // 獲取async節(jié)點(diǎn)(父節(jié)點(diǎn))的函數(shù)體       let info = asyncPath.node.body;        // 將父節(jié)點(diǎn)原來(lái)的函數(shù)體放到try語(yǔ)句中       tryNode.block.body.push(...info.body);        // 將父節(jié)點(diǎn)的內(nèi)容替換成新創(chuàng)建的try語(yǔ)句       info.body = [tryNode];     }   };   return {     name: 'babel-plugin-await-add-trycatch',     visitor   }; };

const merge = require('deepmerge');  // 定義try語(yǔ)句模板 let tryTemplate = ` try { } catch (e) { console.log(CatchError,e) }`;  /*  * catch要打印的信息  * @param {string} filePath - 當(dāng)前執(zhí)行文件的路徑  * @param {string} funcName - 當(dāng)前執(zhí)行方法的名稱(chēng)  * @param {string} customLog - 用戶(hù)自定義的打印信息  */ let catchConsole = (filePath, funcName, customLog) => ` filePath: ${filePath} funcName: ${funcName} ${customLog}:`;  // 默認(rèn)配置 const defaultOptions = {   customLog: 'Error',   exclude: ['node_modules'],   include: [] };  // 判斷執(zhí)行的file文件 是否在 exclude/include 選項(xiàng)內(nèi) function matchesFile(list, filename) {   return list.find((name) => name && filename.includes(name)); }  // 合并選項(xiàng) function mergeOptions(options) {   let { exclude, include } = options;   if (exclude) options.exclude = toArray(exclude);   if (include) options.include = toArray(include);   // 使用merge進(jìn)行合并   return merge.all([defaultOptions, options]); }  function toArray(value) {   return Array.isArray(value) ? value : [value]; }  module.exports = {   tryTemplate,   catchConsole,   defaultOptions,   mergeOptions,   matchesFile,   toArray };