[Bug Report] Unit Testing v-form causes "TypeError: Cannot read property 'componentInstance' of null"

Versions and Environment

Vuetify: 1.5.3 Vue: 2.6.7 Browsers: Chrome 72.0.3626.109 OS: Mac OS 10.14.2

Steps to reproduce

1. Clone Repo
2. Yarn install
3. Run yarn test:unit

Expected Behavior

1. Tests pass when run individually
2. Tests should pass when the entire suite is run

Actual Behavior

1. Tests pass when run individually
2. Tests break when the entire suite is run and v-form contains v-model=“valid”. If I remove the v-model then the entire test suite passes - of course, v-model is required for validation.

Reproduction Link

https://github.com/buys-fran/vue-form-test

Other comments

It could be a leaky test issue, but I am making use of vue-test-utils’ LocalVue to better isolate tests. I believe something in the internal workings of v-form causes this problem.

[fbuys]

I think I found a work around for our use case.

I will paste our setup here perhaps it will help someone.

import Vue from 'vue'
import Vuetify from 'vuetify'
import Vuex from 'vuex'
import Router from 'vue-router'
import axios from 'axios'
import { merge } from 'lodash'
import { mount, createLocalVue } from '@vue/test-utils'

// Can't use LocalVue Issue: https://github.com/vuetifyjs/vuetify/issues/4068#issuecomment-422406319
Vue.use(Vuetify)

const localVue = createLocalVue()
localVue.use(Vuex)
localVue.use(Router)
const router = new Router()

const $http = jest.mock('axios')

const createWrapper = function(component, { overrides, store } = {}) {
  const defaultMountingOptions = {
    mocks: {
      $http,
    },
    propsData: {},
    localVue,
    router,
    store: store || new Vuex.Store({}),
  }

  return mount(component, merge(defaultMountingOptions, overrides))
}

export default createWrapper

[willypelz]

@buys-fran this actually solves the problem stated above. cool