reactjs - react 测试 - UnhandledPromiseRejection

Question

我想用 Jest 和 Enzyme 测试我的应用程序。我收到错误:

node:internal/process/promises:246
          triggerUncaughtException(err, true /* fromPromise */);
          ^

[UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "[object Object]".] {
  code: 'ERR_UNHANDLED_REJECTION'
}

这是由于:

async function checkGet() {
    const fetchedDB = await db.persons.toArray();
    if (fetchedDB.length > 0) {
      setPeople(fetchedDB);
      return;
    } else {
      getPeople();
    }
  }

我试着改变它:

 async function checkGet() {
    const fetchedDB = await db.persons.toArray();
    fetchedDB.catch((e) => {
      console.log(e);
    });
    if (fetchedDB.length > 0) {
      setPeople(fetchedDB);
      return;
    } else {
      getPeople();
    }
  }

像那样:

  async function checkGet() {
    const fetchedDB = await db.persons.toArray().catch((e) => {
      console.log(e);
    });
    if (fetchedDB.length > 0) {
      setPeople(fetchedDB);
      return;
    } else {
      getPeople();
    }
  }

但即使添加了这个，错误仍然存​​在。我正在使用 React 17。这是某种错误吗？

Answer 1

尝试使用 try/catch 包装您的代码。

async function checkGet() {
  try {
    const fetchedDB = await db.persons.toArray();
    if (fetchedDB.length > 0) {
      setPeople(fetchedDB);
      return;
    } else {
      getPeople();
    }
  } catch (err) {
     console.log(err);
  }
}

在 try{} 中抛出的所有错误都将在 catch(err){} 中捕获。