From 22959fe2a72fc7c8d52ea22c6d92df9706272f25 Mon Sep 17 00:00:00 2001
From: Haoqun Jiang <haoqunjiang@gmail.com>
Date: Fri, 22 May 2020 21:45:47 +0800
Subject: [PATCH 1/6] fix: correctly calculate if a custom polyfill is required
 with the given targets

partially fixed the problem mentioned in #5507
---
 packages/@vue/babel-preset-app/index.js | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/@vue/babel-preset-app/index.js b/packages/@vue/babel-preset-app/index.js
index f199db12c0..cffc2f284c 100644
--- a/packages/@vue/babel-preset-app/index.js
+++ b/packages/@vue/babel-preset-app/index.js
@@ -9,12 +9,12 @@ const defaultPolyfills = [
   // this is needed for object rest spread support in templates
   // as vue-template-es2015-compiler 1.8+ compiles it to Object.assign() calls.
   'es.object.assign',
-  // #2012 es6.promise replaces native Promise in FF and causes missing finally
+  // #2012 es.promise replaces native Promise in FF and causes missing finally
   'es.promise.finally'
 ]
 
 function getPolyfills (targets, includes, { ignoreBrowserslistConfig, configPath }) {
-  const getTargets = require('@babel/helper-compilation-targets').default
+  const { default: getTargets, isRequired } = require('@babel/helper-compilation-targets')
   const builtInTargets = getTargets(targets, { ignoreBrowserslistConfig, configPath })
 
   // if no targets specified, include all default polyfills
@@ -22,8 +22,8 @@ function getPolyfills (targets, includes, { ignoreBrowserslistConfig, configPath
     return includes
   }
 
-  const { list } = require('core-js-compat')({ targets: builtInTargets })
-  return includes.filter(item => list.includes(item))
+  const compatData = require('core-js-compat').data
+  return includes.filter(item => isRequired(item, builtInTargets, { compatData }))
 }
 
 module.exports = (context, options = {}) => {
@@ -108,6 +108,7 @@ module.exports = (context, options = {}) => {
     }
   } else if (process.env.VUE_CLI_MODERN_BUILD) {
     // targeting browsers that support <script type="module">
+    // TODO: should use intersections of esmodules & the user defined targets
     targets = { esmodules: true }
   } else {
     targets = rawTargets
@@ -122,8 +123,7 @@ module.exports = (context, options = {}) => {
   if (
     buildTarget === 'app' &&
     useBuiltIns === 'usage' &&
-    !process.env.VUE_CLI_BABEL_TARGET_NODE &&
-    !process.env.VUE_CLI_MODERN_BUILD
+    !process.env.VUE_CLI_BABEL_TARGET_NODE
   ) {
     polyfills = getPolyfills(targets, userPolyfills || defaultPolyfills, {
       ignoreBrowserslistConfig,

From e917b8ccd94a986e357e1eb7f6ccaea52d237378 Mon Sep 17 00:00:00 2001
From: Haoqun Jiang <haoqunjiang@gmail.com>
Date: Fri, 22 May 2020 21:59:55 +0800
Subject: [PATCH 2/6] chore: add a note about removing the `useAbsolutePath` in
 v5

---
 packages/@vue/babel-preset-app/polyfillsPlugin.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/packages/@vue/babel-preset-app/polyfillsPlugin.js b/packages/@vue/babel-preset-app/polyfillsPlugin.js
index dc57d9a7f9..906a7d3d8b 100644
--- a/packages/@vue/babel-preset-app/polyfillsPlugin.js
+++ b/packages/@vue/babel-preset-app/polyfillsPlugin.js
@@ -2,6 +2,9 @@ const { addSideEffect } = require('@babel/helper-module-imports')
 
 // slightly modifiled from @babel/preset-env/src/utils
 // use an absolute path for core-js modules, to fix conflicts of different core-js versions
+// TODO: remove the `useAbsolutePath` option in v5,
+// because `core-js` is sure to be present in newer projects;
+// we only need absolute path for babel runtime helpers, not for polyfills
 function getModulePath (mod, useAbsolutePath) {
   const modPath =
     mod === 'regenerator-runtime'

From 1ae6153ced397684d82c1a73a091c0e32c2bc239 Mon Sep 17 00:00:00 2001
From: Haoqun Jiang <haoqunjiang@gmail.com>
Date: Fri, 22 May 2020 22:09:23 +0800
Subject: [PATCH 3/6] fix: set exact corejs version for preset-env

fixes another issue mentioned in #5507

Note now core-js is listed as an optional peer depedency.
TODO: should remove it from depdencies in the next major.
---
 packages/@vue/babel-preset-app/index.js     | 4 ++--
 packages/@vue/babel-preset-app/package.json | 8 +++++++-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/packages/@vue/babel-preset-app/index.js b/packages/@vue/babel-preset-app/index.js
index cffc2f284c..56bb9053c9 100644
--- a/packages/@vue/babel-preset-app/index.js
+++ b/packages/@vue/babel-preset-app/index.js
@@ -139,7 +139,7 @@ module.exports = (context, options = {}) => {
 
   const envOptions = {
     bugfixes,
-    corejs: useBuiltIns ? 3 : false,
+    corejs: useBuiltIns ? require('core-js/package.json').version : false,
     spec,
     loose,
     debug,
@@ -206,7 +206,7 @@ module.exports = (context, options = {}) => {
       presets: [
         [require('@babel/preset-env'), {
           useBuiltIns,
-          corejs: useBuiltIns ? 3 : false
+          corejs: useBuiltIns ? require('core-js/package.json').version : false
         }]
       ]
     }]
diff --git a/packages/@vue/babel-preset-app/package.json b/packages/@vue/babel-preset-app/package.json
index 98b3f03490..f594f24031 100644
--- a/packages/@vue/babel-preset-app/package.json
+++ b/packages/@vue/babel-preset-app/package.json
@@ -38,6 +38,12 @@
     "core-js-compat": "^3.6.5"
   },
   "peerDependencies": {
-    "@babel/core": "*"
+    "@babel/core": "*",
+    "core-js": "^3"
+  },
+  "peerDependenciesMeta": {
+    "core-js": {
+      "optional": true
+    }
   }
 }

From 733ba10244e63a9a46667764836a6f7fb95badc6 Mon Sep 17 00:00:00 2001
From: Haoqun Jiang <haoqunjiang@gmail.com>
Date: Sat, 23 May 2020 00:47:31 +0800
Subject: [PATCH 4/6] fix(modern-mode): should use intersection of modern
 browsers and user-specified targets

We don't need to target browsers that users don't need, even if it is
a browser that supports `script type="module"`.

With this change, with the default target of "last 2 versions", we no
longer has to deal with the obsolete versions of evergreen browsers that
comes with all kinds of bugs.
This further improves the modern build bundle size. Maybe even better
than [the `bugfixes` option of `preset-env`](https://babeljs.io/docs/en/babel-preset-env#bugfixes)
---
 .../__tests__/babel-preset.spec.js            |  14 ++-
 packages/@vue/babel-preset-app/index.js       | 109 +++++++++++++-----
 packages/@vue/babel-preset-app/package.json   |   3 +-
 3 files changed, 88 insertions(+), 38 deletions(-)

diff --git a/packages/@vue/babel-preset-app/__tests__/babel-preset.spec.js b/packages/@vue/babel-preset-app/__tests__/babel-preset.spec.js
index 0fdef29d97..276b2cd11f 100644
--- a/packages/@vue/babel-preset-app/__tests__/babel-preset.spec.js
+++ b/packages/@vue/babel-preset-app/__tests__/babel-preset.spec.js
@@ -48,20 +48,24 @@ test('polyfill detection', () => {
   expect(code).toMatch('"core-js/modules/es.map"')
 })
 
-test('modern mode always skips polyfills', () => {
+test('modern mode always skips unnecessary polyfills', () => {
   process.env.VUE_CLI_MODERN_BUILD = true
   let { code } = babel.transformSync(`
     const a = new Map()
   `.trim(), {
     babelrc: false,
     presets: [[preset, {
-      targets: { ie: 9 },
+      targets: { ie: 9, chrome: 5 },
       useBuiltIns: 'usage'
     }]],
     filename: 'test-entry-file.js'
   })
-  // default includes
-  expect(code).not.toMatch(getAbsolutePolyfill('es.promise'))
+  // default includes that are supported in all modern browsers should be skipped
+  expect(code).not.toMatch('es.assign')
+  // according to the compat table, es.promise is fully supported in only chrome >= 67
+  // which is greater than both the minimum version supporting `module` (61) and the user-specified version (5)
+  // so it's still required
+  expect(code).toMatch('es.promise')
   // usage-based detection
   expect(code).not.toMatch('"core-js/modules/es.map"')
 
@@ -70,7 +74,7 @@ test('modern mode always skips polyfills', () => {
   `.trim(), {
     babelrc: false,
     presets: [[preset, {
-      targets: { ie: 9 },
+      targets: { ie: 9, chrome: 5 },
       useBuiltIns: 'entry'
     }]],
     filename: 'test-entry-file.js'
diff --git a/packages/@vue/babel-preset-app/index.js b/packages/@vue/babel-preset-app/index.js
index 56bb9053c9..a785a86b0f 100644
--- a/packages/@vue/babel-preset-app/index.js
+++ b/packages/@vue/babel-preset-app/index.js
@@ -1,4 +1,5 @@
 const path = require('path')
+const semver = require('semver')
 
 const defaultPolyfills = [
   // promise polyfill alone doesn't work in IE,
@@ -13,17 +14,62 @@ const defaultPolyfills = [
   'es.promise.finally'
 ]
 
-function getPolyfills (targets, includes, { ignoreBrowserslistConfig, configPath }) {
-  const { default: getTargets, isRequired } = require('@babel/helper-compilation-targets')
-  const builtInTargets = getTargets(targets, { ignoreBrowserslistConfig, configPath })
+function getPolyfills (
+  rawTargets,
+  includes,
+  { ignoreBrowserslistConfig, configPath }
+) {
+  const {
+    default: getTargets,
+    isRequired
+  } = require('@babel/helper-compilation-targets')
+  let targets = getTargets(rawTargets, {
+    ignoreBrowserslistConfig,
+    configPath
+  })
 
   // if no targets specified, include all default polyfills
-  if (!targets && !Object.keys(builtInTargets).length) {
+  if (
+    !rawTargets &&
+    !Object.keys(targets).length &&
+    !process.env.VUE_CLI_MODERN_BUILD
+  ) {
     return includes
   }
 
+  // targeting browsers that support <script type="module">
+  if (process.env.VUE_CLI_MODERN_BUILD) {
+    const modernTargets = getTargets(
+      { esmodules: true },
+      { ignoreBrowserslistConfig: true, configPath }
+    )
+
+    // use the intersection of modern mode browsers and user defined targets config
+    const intersection = Object.keys(modernTargets).reduce(
+      (results, browser) => {
+        // exclude the browsers that the user does not need
+        if (!targets[browser]) {
+          return results
+        }
+
+        // if the user-specified version is higher the minimum version that supports esmodule, than use it
+        results[browser] = semver.gt(
+          semver.coerce(modernTargets[browser]),
+          semver.coerce(targets[browser])
+        )
+          ? modernTargets[browser]
+          : targets[browser]
+
+        return results
+      },
+      {}
+    )
+
+    targets = intersection
+  }
+
   const compatData = require('core-js-compat').data
-  return includes.filter(item => isRequired(item, builtInTargets, { compatData }))
+  return includes.filter(item => isRequired(item, targets, { compatData }))
 }
 
 module.exports = (context, options = {}) => {
@@ -36,7 +82,7 @@ module.exports = (context, options = {}) => {
   // dropping them may break some projects.
   // So in the following blocks we don't directly test the `NODE_ENV`.
   // Rather, we turn it into the two commonly used feature flags.
-  if (process.env.NODE_ENV === 'test') {
+  if (!process.env.VUE_CLI_TEST && process.env.NODE_ENV === 'test') {
     // Both Jest & Mocha set NODE_ENV to 'test'.
     // And both requires the `node` target.
     process.env.VUE_CLI_BABEL_TARGET_NODE = 'true'
@@ -62,7 +108,7 @@ module.exports = (context, options = {}) => {
     bugfixes = true,
     targets: rawTargets,
     spec,
-    ignoreBrowserslistConfig = !!process.env.VUE_CLI_MODERN_BUILD,
+    ignoreBrowserslistConfig,
     configPath,
     include,
     exclude,
@@ -88,7 +134,30 @@ module.exports = (context, options = {}) => {
     version = runtimeVersion
   } = options
 
-  // resolve targets
+  // included-by-default polyfills. These are common polyfills that 3rd party
+  // dependencies may rely on (e.g. Vuex relies on Promise), but since with
+  // useBuiltIns: 'usage' we won't be running Babel on these deps, they need to
+  // be force-included.
+  let polyfills
+  const buildTarget = process.env.VUE_CLI_BUILD_TARGET || 'app'
+  if (
+    buildTarget === 'app' &&
+    useBuiltIns === 'usage' &&
+    !process.env.VUE_CLI_BABEL_TARGET_NODE
+  ) {
+    polyfills = getPolyfills(rawTargets, userPolyfills || defaultPolyfills, {
+      ignoreBrowserslistConfig,
+      configPath
+    })
+    plugins.push([
+      require('./polyfillsPlugin'),
+      { polyfills, entryFiles, useAbsolutePath: !!absoluteRuntime }
+    ])
+  } else {
+    polyfills = []
+  }
+
+  // resolve targets for preset-env
   let targets
   if (process.env.VUE_CLI_BABEL_TARGET_NODE) {
     // running tests in Node.js
@@ -108,35 +177,11 @@ module.exports = (context, options = {}) => {
     }
   } else if (process.env.VUE_CLI_MODERN_BUILD) {
     // targeting browsers that support <script type="module">
-    // TODO: should use intersections of esmodules & the user defined targets
     targets = { esmodules: true }
   } else {
     targets = rawTargets
   }
 
-  // included-by-default polyfills. These are common polyfills that 3rd party
-  // dependencies may rely on (e.g. Vuex relies on Promise), but since with
-  // useBuiltIns: 'usage' we won't be running Babel on these deps, they need to
-  // be force-included.
-  let polyfills
-  const buildTarget = process.env.VUE_CLI_BUILD_TARGET || 'app'
-  if (
-    buildTarget === 'app' &&
-    useBuiltIns === 'usage' &&
-    !process.env.VUE_CLI_BABEL_TARGET_NODE
-  ) {
-    polyfills = getPolyfills(targets, userPolyfills || defaultPolyfills, {
-      ignoreBrowserslistConfig,
-      configPath
-    })
-    plugins.push([
-      require('./polyfillsPlugin'),
-      { polyfills, entryFiles, useAbsolutePath: !!absoluteRuntime }
-    ])
-  } else {
-    polyfills = []
-  }
-
   const envOptions = {
     bugfixes,
     corejs: useBuiltIns ? require('core-js/package.json').version : false,
diff --git a/packages/@vue/babel-preset-app/package.json b/packages/@vue/babel-preset-app/package.json
index f594f24031..c7a5af3bff 100644
--- a/packages/@vue/babel-preset-app/package.json
+++ b/packages/@vue/babel-preset-app/package.json
@@ -35,7 +35,8 @@
     "@vue/babel-preset-jsx": "^1.1.2",
     "babel-plugin-dynamic-import-node": "^2.3.3",
     "core-js": "^3.6.5",
-    "core-js-compat": "^3.6.5"
+    "core-js-compat": "^3.6.5",
+    "semver": "^6.1.0"
   },
   "peerDependencies": {
     "@babel/core": "*",

From 57010e22eebb26d958957a4ffb0132c23df74dcc Mon Sep 17 00:00:00 2001
From: Haoqun Jiang <haoqunjiang@gmail.com>
Date: Sat, 23 May 2020 12:08:40 +0800
Subject: [PATCH 5/6] test: use a more up-to-date test configuration

---
 .../__tests__/babel-preset.spec.js            | 27 +++++++++++++------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/packages/@vue/babel-preset-app/__tests__/babel-preset.spec.js b/packages/@vue/babel-preset-app/__tests__/babel-preset.spec.js
index 276b2cd11f..1b2832f00f 100644
--- a/packages/@vue/babel-preset-app/__tests__/babel-preset.spec.js
+++ b/packages/@vue/babel-preset-app/__tests__/babel-preset.spec.js
@@ -52,37 +52,48 @@ test('modern mode always skips unnecessary polyfills', () => {
   process.env.VUE_CLI_MODERN_BUILD = true
   let { code } = babel.transformSync(`
     const a = new Map()
+    console.log(globalThis)
   `.trim(), {
     babelrc: false,
     presets: [[preset, {
-      targets: { ie: 9, chrome: 5 },
+      targets: { ie: 9, safari: '12' },
       useBuiltIns: 'usage'
     }]],
     filename: 'test-entry-file.js'
   })
   // default includes that are supported in all modern browsers should be skipped
   expect(code).not.toMatch('es.assign')
-  // according to the compat table, es.promise is fully supported in only chrome >= 67
-  // which is greater than both the minimum version supporting `module` (61) and the user-specified version (5)
-  // so it's still required
-  expect(code).toMatch('es.promise')
+  // though es.promise is not supported in all modern browsers
+  // (modern: safari >= 10.1, es.promise: safrai >= 11)
+  // the custom configuration only expects to support safari >= 12
+  // so it can be skipped
+  expect(code).not.toMatch('es.promise"')
+  // es.promise.finally is supported in safari >= 13.0.3
+  // so still needs to be included
+  expect(code).toMatch('es.promise.finally')
+
   // usage-based detection
-  expect(code).not.toMatch('"core-js/modules/es.map"')
+  // Map is supported in all modern browsers
+  expect(code).not.toMatch('es.map')
+  // globalThis is not supported until safari 12.1
+  expect(code).toMatch('es.global-this')
 
   ;({ code } = babel.transformSync(`
     const a = new Map()
   `.trim(), {
     babelrc: false,
     presets: [[preset, {
-      targets: { ie: 9, chrome: 5 },
+      targets: { ie: 9, safari: '12' },
       useBuiltIns: 'entry'
     }]],
     filename: 'test-entry-file.js'
   }))
   // default includes
-  expect(code).not.toMatch(getAbsolutePolyfill('es.promise'))
+  expect(code).not.toMatch('es.promise"')
+  expect(code).not.toMatch('es.promise.finally')
   // usage-based detection
   expect(code).not.toMatch('"core-js/modules/es.map"')
+  expect(code).not.toMatch('es.global-this')
   delete process.env.VUE_CLI_MODERN_BUILD
 })
 

From 53e60b2fe289359b9c007917af6ce97865347d01 Mon Sep 17 00:00:00 2001
From: Haoqun Jiang <haoqunjiang@gmail.com>
Date: Sat, 23 May 2020 12:37:00 +0800
Subject: [PATCH 6/6] fix: also apply the intersection logic to web components
 target

---
 packages/@vue/babel-preset-app/index.js | 147 ++++++++++++------------
 1 file changed, 72 insertions(+), 75 deletions(-)

diff --git a/packages/@vue/babel-preset-app/index.js b/packages/@vue/babel-preset-app/index.js
index a785a86b0f..be8775f33e 100644
--- a/packages/@vue/babel-preset-app/index.js
+++ b/packages/@vue/babel-preset-app/index.js
@@ -14,58 +14,70 @@ const defaultPolyfills = [
   'es.promise.finally'
 ]
 
-function getPolyfills (
-  rawTargets,
-  includes,
-  { ignoreBrowserslistConfig, configPath }
-) {
-  const {
-    default: getTargets,
-    isRequired
-  } = require('@babel/helper-compilation-targets')
-  let targets = getTargets(rawTargets, {
-    ignoreBrowserslistConfig,
-    configPath
-  })
+const {
+  default: getTargets,
+  isRequired
+} = require('@babel/helper-compilation-targets')
 
-  // if no targets specified, include all default polyfills
-  if (
-    !rawTargets &&
-    !Object.keys(targets).length &&
-    !process.env.VUE_CLI_MODERN_BUILD
-  ) {
-    return includes
-  }
+function getIntersectionTargets (targets, constraintTargets) {
+  const intersection = Object.keys(constraintTargets).reduce(
+    (results, browser) => {
+      // exclude the browsers that the user does not need
+      if (!targets[browser]) {
+        return results
+      }
 
-  // targeting browsers that support <script type="module">
-  if (process.env.VUE_CLI_MODERN_BUILD) {
-    const modernTargets = getTargets(
-      { esmodules: true },
-      { ignoreBrowserslistConfig: true, configPath }
-    )
+      // if the user-specified version is higher the minimum version that supports esmodule, than use it
+      results[browser] = semver.gt(
+        semver.coerce(constraintTargets[browser]),
+        semver.coerce(targets[browser])
+      )
+        ? constraintTargets[browser]
+        : targets[browser]
 
-    // use the intersection of modern mode browsers and user defined targets config
-    const intersection = Object.keys(modernTargets).reduce(
-      (results, browser) => {
-        // exclude the browsers that the user does not need
-        if (!targets[browser]) {
-          return results
-        }
+      return results
+    },
+    {}
+  )
 
-        // if the user-specified version is higher the minimum version that supports esmodule, than use it
-        results[browser] = semver.gt(
-          semver.coerce(modernTargets[browser]),
-          semver.coerce(targets[browser])
-        )
-          ? modernTargets[browser]
-          : targets[browser]
+  return intersection
+}
 
-        return results
-      },
-      {}
-    )
+function getModernTargets (targets) {
+  const allModernTargets = getTargets(
+    { esmodules: true },
+    { ignoreBrowserslistConfig: true }
+  )
+
+  // use the intersection of modern mode browsers and user defined targets config
+  return getIntersectionTargets(targets, allModernTargets)
+}
 
-    targets = intersection
+function getWCTargets (targets) {
+  // targeting browsers that at least support ES2015 classes
+  // https://github.com/babel/babel/blob/v7.9.6/packages/babel-compat-data/data/plugins.json#L194-L204
+  const allWCTargets = getTargets(
+    {
+      browsers: [
+        'Chrome >= 46',
+        'Firefox >= 45',
+        'Safari >= 10',
+        'Edge >= 13',
+        'iOS >= 10',
+        'Electron >= 0.36'
+      ]
+    },
+    { ignoreBrowserslistConfig: true }
+  )
+
+  // use the intersection of browsers supporting Web Components and user defined targets config
+  return getIntersectionTargets(targets, allWCTargets)
+}
+
+function getPolyfills (targets, includes) {
+  // if no targets specified, include all default polyfills
+  if (!targets || !Object.keys(targets).length) {
+    return includes
   }
 
   const compatData = require('core-js-compat').data
@@ -134,6 +146,19 @@ module.exports = (context, options = {}) => {
     version = runtimeVersion
   } = options
 
+  // resolve targets for preset-env
+  let targets = getTargets(rawTargets, { ignoreBrowserslistConfig, configPath })
+  if (process.env.VUE_CLI_BABEL_TARGET_NODE) {
+    // running tests in Node.js
+    targets = { node: 'current' }
+  } else if (process.env.VUE_CLI_BUILD_TARGET === 'wc' || process.env.VUE_CLI_BUILD_TARGET === 'wc-async') {
+    // targeting browsers that at least support ES2015 classes
+    targets = getWCTargets(targets)
+  } else if (process.env.VUE_CLI_MODERN_BUILD) {
+    // targeting browsers that at least support <script type="module">
+    targets = getModernTargets(targets)
+  }
+
   // included-by-default polyfills. These are common polyfills that 3rd party
   // dependencies may rely on (e.g. Vuex relies on Promise), but since with
   // useBuiltIns: 'usage' we won't be running Babel on these deps, they need to
@@ -145,10 +170,7 @@ module.exports = (context, options = {}) => {
     useBuiltIns === 'usage' &&
     !process.env.VUE_CLI_BABEL_TARGET_NODE
   ) {
-    polyfills = getPolyfills(rawTargets, userPolyfills || defaultPolyfills, {
-      ignoreBrowserslistConfig,
-      configPath
-    })
+    polyfills = getPolyfills(targets, userPolyfills || defaultPolyfills)
     plugins.push([
       require('./polyfillsPlugin'),
       { polyfills, entryFiles, useAbsolutePath: !!absoluteRuntime }
@@ -157,31 +179,6 @@ module.exports = (context, options = {}) => {
     polyfills = []
   }
 
-  // resolve targets for preset-env
-  let targets
-  if (process.env.VUE_CLI_BABEL_TARGET_NODE) {
-    // running tests in Node.js
-    targets = { node: 'current' }
-  } else if (process.env.VUE_CLI_BUILD_TARGET === 'wc' || process.env.VUE_CLI_BUILD_TARGET === 'wc-async') {
-    // targeting browsers that at least support ES2015 classes
-    // https://github.com/babel/babel/blob/master/packages/babel-preset-env/data/plugins.json#L52-L61
-    targets = {
-      browsers: [
-        'Chrome >= 49',
-        'Firefox >= 45',
-        'Safari >= 10',
-        'Edge >= 13',
-        'iOS >= 10',
-        'Electron >= 0.36'
-      ]
-    }
-  } else if (process.env.VUE_CLI_MODERN_BUILD) {
-    // targeting browsers that support <script type="module">
-    targets = { esmodules: true }
-  } else {
-    targets = rawTargets
-  }
-
   const envOptions = {
     bugfixes,
     corejs: useBuiltIns ? require('core-js/package.json').version : false,