has been solved, there are no questions and answers on SegmentDefault, and the answers on StockOverflow are very obscure. After further study of require.context, I found that this function is used to reference resources, but the timing of my reference will not be written outside the declaration cycle. Here is the original code:

<script type='text/ecmascript-6'>
// svg
const requireAll = requireContext => requireContext.keys().map(requireContext)
const req = require.context('../../assets/svg-icons', false, /\.svg$/)
requireAll(req)

export default {
  name: 'SvgIcon',

  props: {
    iconClass: {
      type: String,
      required: true
    },
    className: {
      type: String
    }
  },
...

after the change, it looks like this:

export default {
  ...

  created () {
    this.requireSvgs()
  },

  methods: {
    // 
    requireSvgs () {
      const requireAll = requireContext => requireContext.keys().map(requireContext)
      const req = require.context('../../assets/svg-icons', false, /\.svg$/)
      requireAll(req)
    }
  }
}

write this way, you can pass the test

import Vue from 'vue'
import { shallowMount, createLocalVue } from '@vue/test-utils'
import ElementUI from 'element-ui'
import Vuex from 'vuex'
import SvgIcon from '@/components/base/SvgIcon'
import Login from '@/components/Login'

Vue.use(ElementUI)
Vue.component('svg-icon', SvgIcon)

// Vue
const localVue = createLocalVue()
localVue.use(Vuex)

describe('Login', () => {
  let wrapper

  beforeEach(() => {
    wrapper = shallowMount(Login, {
      localVue
    })
  })

  afterEach(() => {
    wrapper.destroy()
  })

  test('LoginVue', () => {
    expect(wrapper.isVueInstance()).toBeTruthy()
  })
})

record here for reference to friends in need.

Note: the code was modified the next day to remove the code referenced by svg resources from the SvgIcon component to simplify the SvgIcon component, which is only used to render the icon icon, which is also conducive to the later testing of this component, and the introduction of resource code is transplanted to main.js.

jest only goes babel (babel-jest), not webpack, so there's nothing you can do about it. The only way is to replace the code

https://stackoverflow.com/que. where there is a mock method

you can use babel-plugin-require-context-hook, https://www.npmjs.com/package.