feat(cli): add babel loose mode config

babel.config.js

@@ -1,3 +1,5 @@
 module.exports = {
-  presets: ['@vant/cli/preset'],
+  presets: [
+    ['@vant/cli/preset', { loose: process.env.BUILD_TARGET === 'package' }],
+  ],
 };

packages/vant-cli/preset.js

@@ -1,3 +1,3 @@
 const babelConfig = require('./lib/config/babel.config');
 
-module.exports = api => babelConfig(api);
+module.exports = (api, options) => babelConfig(api, options);

packages/vant-cli/src/commands/build.ts

@@ -24,6 +24,7 @@ import {
   isTestDir,
   setNodeEnv,
   setModuleEnv,
+  setBuildTarget,
 } from '../common';
 
 async function compileFile(filePath: string) {
@@ -64,12 +65,14 @@ async function compileDir(dir: string) {
 
 async function buildEs() {
   setModuleEnv('esmodule');
+  setBuildTarget('package');
   await copy(SRC_DIR, ES_DIR);
   await compileDir(ES_DIR);
 }
 
 async function buildLib() {
   setModuleEnv('commonjs');
+  setBuildTarget('package');
   await copy(SRC_DIR, LIB_DIR);
   await compileDir(LIB_DIR);
 }

packages/vant-cli/src/config/babel.config.ts

@@ -1,6 +1,10 @@
 import { ConfigAPI } from '@babel/core';
 
-module.exports = function (api?: ConfigAPI) {
+type PresetOption = {
+  loose?: boolean;
+};
+
+module.exports = function (api?: ConfigAPI, options: PresetOption = {}) {
   if (api) {
     api.cache.never();
   }
@@ -15,6 +19,7 @@ module.exports = function (api?: ConfigAPI) {
         '@babel/preset-env',
         {
           modules: useESModules ? false : 'commonjs',
+          loose: options.loose,
         },
       ],
       '@babel/preset-typescript',

packages/vant-lazyload/babel.config.js

@@ -1,3 +1,3 @@
 module.exports = {
-  presets: ['@vant/cli/preset'],
+  presets: [['@vant/cli/preset', { loose: true }]],
 };

packages/vant-popperjs/babel.config.js

@@ -1,3 +1,3 @@
 module.exports = {
-  presets: ['@vant/cli/preset'],
+  presets: [['@vant/cli/preset', { loose: true }]],
 };