每次按提交的报错信息：

runtime-core.esm-bundler.js:41 [Vue warn]: Unhandled error during execution of component event handler 
  at <ElButton onClick=fn<login> class="button" type="primary"  ... > 

代码：

const login = async () => {
  await form.value.validate()
  const res = await userLoginService(formModel.value)
  userStore.setToken(res.data.token)
  ElMessage.success('登录成功')
  router.push('/')
}

解决方法：

用 try/catch 抛出错误

const login = async () => {
  try {
    await form.value.validate()
    const res = await userLoginService(formModel.value)
    userStore.setToken(res.data.token)
    ElMessage.success('登录成功')
    router.push('/')
  } catch (error) {
    ElMessage.error('登录失败')
  }
}

现在运行就没问题了