vue/test/helpers/classlist.js

beforeEach(() => {
  jasmine.addMatchers({
    // since classList may not be supported in all browsers
    toHaveClass: () => {
      return {
        compare: (el, cls) => {
          const pass = el.classList
            ? el.classList.contains(cls)
            : el.getAttribute('class').split(/\s+/g).indexOf(cls) > -1
          return {
            pass,
            message: `Expected element${pass ? ' ' : ' not '}to have class ${cls}`
          }
        }
      }
    }
  })
})