解决了的。。
这是一个处理异步/等待函数的问题。。。在我的组件中
submitForm: async function() {
....
所以我在测试中使用了同花顺的承诺
yarn add -D flush-promises
然后
import flushPromises from "flush-promises";
...
it("should not sendMessage - invalid form", async () => {
...
wrapper = mount(ContactForm, options);
...
// then
const btnSubmit = wrapper.find("#btnSubmit");
btnSubmit.trigger("click");
await flushPromises();
...
const alert = wrapper.find(".v-alert");
console.log("INVALID FORM ALERT: ", alert.html());
<div class="v-alert error" style=""><div>One or more fields are invalid. Please, review your input and submit</div><a class="v-alert__dismissible"><i aria-hidden="true" class="v-icon v-icon--right material-icons theme--light">cancel</i></a></div>