fix: pin babel version (fix #1162)

Author: yyx990803

packages/@vue/babel-preset-app/__tests__/babel-preset.spec.js

@@ -31,8 +31,8 @@ test('object spread', () => {
   const { code } = babel.transformSync(`
     const a = { ...b }
   `.trim(), defaultOptions)
-  expect(code).toMatch(`import "core-js/modules/es6.object.assign"`)
-  expect(code).toMatch(`var a = Object.assign({}, b)`)
+  expect(code).toMatch(`import _objectSpread from`)
+  expect(code).toMatch(`var a = _objectSpread({}, b)`)
 })
 
 test('dynamic import', () => {

packages/@vue/babel-preset-app/index.js

@@ -38,7 +38,7 @@ module.exports = (context, options = {}) => {
   // and rest object spread.
   presets.push([require('@babel/preset-stage-2'), {
     useBuiltIns: true,
-    decoratorsLegacy: options.decoratorsLegacy || false
+    decoratorsLegacy: options.decoratorsLegacy !== false
   }])
 
   // transform runtime, but only for helpers

packages/@vue/babel-preset-app/package.json

@@ -21,11 +21,11 @@
   },
   "homepage": "https://github.com/vuejs/vue-cli/packages/@vue/babel-preset-app#readme",
   "dependencies": {
-    "@babel/plugin-syntax-jsx": "^7.0.0-0",
-    "@babel/plugin-transform-runtime": "^7.0.0-0",
-    "@babel/preset-env": "^7.0.0-0",
-    "@babel/preset-stage-2": "^7.0.0-0",
-    "@babel/runtime": "^7.0.0-0",
+    "@babel/plugin-syntax-jsx": "7.0.0-beta.46",
+    "@babel/plugin-transform-runtime": "7.0.0-beta.46",
+    "@babel/preset-env": "7.0.0-beta.46",
+    "@babel/preset-stage-2": "7.0.0-beta.46",
+    "@babel/runtime": "7.0.0-beta.46",
     "babel-helper-vue-jsx-merge-props": "^2.0.3",
     "babel-plugin-dynamic-import-node": "^1.2.0",
     "babel-plugin-transform-vue-jsx": "^4.0.1"

packages/@vue/cli-plugin-babel/package.json

@@ -19,7 +19,7 @@
   },
   "homepage": "https://github.com/vuejs/vue-cli/packages/@vue/cli-plugin-babel#readme",
   "dependencies": {
-    "@babel/core": "^7.0.0-0",
+    "@babel/core": "7.0.0-beta.46",
     "@vue/babel-preset-app": "^3.0.0-beta.6",
     "babel-loader": "^8.0.0-0"
   },