Allow mocks to be set in config object

Author: lmiller1990

packages/shared/merge-options.js

@@ -16,12 +16,29 @@ function getStubs (optionStubs, config) {
   }
 }
 
+function getMocks (optionMocks, config) {
+  if (optionMocks ||
+    (config.mocks && Object.keys(config.mocks).length > 0)) {
+    if (Array.isArray(optionMocks)) {
+      return [
+        ...optionMocks,
+        ...Object.keys(config.mocks || {})]
+    } else {
+      return {
+        ...config.mocks,
+        ...optionMocks
+      }
+    }
+  }
+}
+
 export function mergeOptions (
   options: Options,
   config: Options
 ): Options {
   return {
     ...options,
-    stubs: getStubs(options.stubs, config)
+    stubs: getStubs(options.stubs, config),
+    mocks: getMocks(options.mocks, config)
   }
 }

packages/test-utils/src/config.js

@@ -5,5 +5,6 @@ export default {
   stubs: {
     transition: TransitionStub,
     'transition-group': TransitionGroupStub
-  }
+  },
+  mocks: {}
 }

test/specs/config.spec.js

@@ -2,7 +2,8 @@ import {
   mount,
   config,
   TransitionStub,
-  TransitionGroupStub
+  TransitionGroupStub,
+  createLocalVue
 } from '~vue/test-utils'
 
 describe('config', () => {
@@ -33,6 +34,29 @@ describe('config', () => {
     expect(wrapper.contains(TransitionGroupStub)).to.equal(true)
   })
 
+  it('mocks a global variable', () => {
+    const localVue = createLocalVue()
+    const t = 'real value'
+    localVue.prototype.$t = t
+
+    const testComponent = {
+      template: `
+        <div>{{ $t }}</div>
+      `
+    }
+
+    config.mocks['$t'] = 'mock value'
+
+    const wrapper = mount(testComponent, {
+      localVue, t
+    })
+
+    expect(wrapper.vm.$t).to.equal('mock value')
+    expect(wrapper.text()).to.equal('mock value')
+
+    localVue.prototype.$t = undefined
+  })
+
   it('doesn\'t stub transition when config.stubs.transition is set to false', () => {
     const testComponent = {
       template: `