Redux Saga：等待承诺

Question

我有一个已经调用的承诺，必须等待。基本上：

const foo = () => Promise.resolve('foo'); // The real promise takes time to resolve.

const result = foo();

await result; // This line has to happen in the saga

如何等待未决的承诺？如果我将它包装在 call Redux Saga 尝试调用它并崩溃。

Answer 1

const myFunc = async () => {
  const result = await foo();
  return result;
  // or just return foo() without await, as it is last statememnt in async func
}

否则你总是可以做

foo()
  .then((result) => console.log('result', result))
  .catch((err) => console.error(err));

Answer 2

如果您身处传奇，只需 yield 承诺即可。 Redux saga 将等待它解决然后恢复 saga，就像 await 在 async 函数中所做的那样：

const foo = () => Promise.resolve('foo');
const resultingPromise = foo();

function* exampleSaga() {
  const result = yield resultingPromise;
  console.log(result); // 'foo'
}

如果 promise 可能会被拒绝，您可以将其包装在 try catch 中：

try {
  const result = yield resultingPromise;
  console.log(result);
} catch(err) {
  console.log('promise rejected', err);
}

Redux Saga：等待承诺

Redux Saga: Await Promise

javascript

redux-saga