vue中执行单元测试报错：import mount from vuetest-utilsimport NavBox from NavBoxvuedescribeNavBox = testis a Vue instance = const wrapper = mountNavBox nav expectwrappertoBeTruthy

The error you are encountering is likely due to the fact that you are not providing the propsData option correctly when mounting the component.

Here is the corrected code:

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

describe('NavBox', () => {
  test('is a Vue instance', () => {
    const wrapper = mount(NavBox, {
      propsData: {
        nav: {}
      }
    })
    expect(wrapper).toBeTruthy()
  })
})

In the above code, the propsData option is used to pass the nav prop to the NavBox component. By providing the propsData option correctly, the error should be resolved.