Jestテスト実行時「Unknown custom element」が発生した場合の対処法

$ yarn test
yarn run v1.17.3
$ jest --config jest.config.js
 PASS  test/Button.spec.js
  Button
    ✓ is a Vue instance (18ms)

  console.error node_modules/vue/dist/vue.runtime.common.dev.js:621
    [Vue warn]: Unknown custom element: <v-btn> - did you register the component correctly? For recursive components, make sure to provide the "name" option.

    found in

    ---> <Button>
           <Root>

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        2.588s
Ran all test suites.
✨  Done in 5.91s.

{
  "scripts": {
    "test": "jest --config jest.config.js",
  },
}

<template>
  <v-btn large color="primary" @click="log">
    ボタン
  </v-btn>
</template>

<script>

export default {
  name: 'Button',
  methods: {
    log() {
      console.log('hoge')
    }
  }
}
</script>

import { mount } from '@vue/test-utils'
import Button from '@/components/Button.vue'

describe('Button', () => {
  test('is a Vue instance', () => {
    const wrapper = mount(Button)
    expect(wrapper.isVueInstance()).toBeTruthy()
  })
})

import Vue from 'vue'
import VueTestUtils from '@vue/test-utils'

Vue.config.silent = true

// Mock Vuetify components
VueTestUtils.config.stubs['v-btn'] = '<button><slot /></button>'

module.exports = {
  setupFiles: ['<rootDir>/test/jest.setup.js'],    // Load Mock setting
  moduleNameMapper: {
    '^@/(.*)$': '<rootDir>/$1',
    '^~/(.*)$': '<rootDir>/$1'
  },
  transform: {
    '^.+\\.js$': 'babel-jest',
    '.*\\.(vue)$': 'vue-jest'
  },
  moduleFileExtensions: ['js', 'json', 'vue']
}