use babel-plugin-istanbul instead

build/karma.cover.config.js

@@ -15,8 +15,8 @@ module.exports = function (config) {
 
   // add babel-plugin-coverage for code intrumentation
   options.webpack.babel = {
-    plugins: [['coverage', {
-      ignore: [
+    plugins: [['istanbul', {
+      exclude: [
         'test/',
         'src/compiler/parser/html-parser.js',
         'src/core/instance/proxy.js',

package.json

@@ -63,7 +63,7 @@
     "babel-eslint": "^7.1.0",
     "babel-helper-vue-jsx-merge-props": "^2.0.2",
     "babel-loader": "^6.2.4",
-    "babel-plugin-coverage": "^1.0.0",
+    "babel-plugin-istanbul": "^3.0.0",
     "babel-plugin-syntax-jsx": "^6.18.0",
     "babel-plugin-transform-vue-jsx": "^3.2.0",
     "babel-preset-es2015": "^6.9.0",

src/core/observer/index.js

@@ -89,9 +89,8 @@ function protoAugment (target, src: Object) {
 /**
  * Augment an target Object or Array by defining
  * hidden properties.
- *
- * istanbul ignore next
  */
+/* istanbul ignore next */
 function copyAugment (target: Object, src: Object, keys: Array<string>) {
   for (let i = 0, l = keys.length; i < l; i++) {
     const key = keys[i]

src/platforms/web/runtime/node-ops.js

@@ -53,10 +53,6 @@ export function setTextContent (node: Node, text: string) {
   node.textContent = text
 }
 
-export function childNodes (node: Node): NodeList<Node> {
-  return node.childNodes
-}
-
 export function setAttribute (node: Element, key: string, val: string) {
   node.setAttribute(key, val)
 }