英文:
Promise.all inside try-catch block - error not caught
问题
我在SoF上看到一些类似的帖子，但它们似乎不是完全相同的东西。
我对JavaScript还不太熟悉，所以可能漏掉了一些明显的东西。
以下是翻译好的代码部分：
在第一个示例中，catch 子句按照我期望的方式运行，也就是说它真正捕获了funcThatThrowsError 中抛出的错误。
然而，在第二个示例中，catch 子句未捕获错误。为什么会这样呢？
请注意，如果将上面的示例更改为以下方式：
那么这个catch 子句确实捕获了错误。
我的问题是：
- 为什么会发生这种情况？
- 这是否意味着当使用
Promise.all时，我必须为传递给Promise.all的每个 promise 定义一个.catch(...)函数，否则如果任何 promise 抛出异常，它将不会被任何地方捕获，并可能导致应用程序崩溃？
谢谢。
英文:
I saw some similar thread on SoF, but they didn't seem to be the exact same thing.
I'm new to javascript, so I might be missing something obvious.
The following code:
async function funcThatThrowsError() {
throw new Error('some error');
}
(async () => {
try {
await funcThatThrowsError();
} catch (error) {
console.log('error caught');
}
}
Works as I expect, meaning the catch clause is really catching the error thrown inside the funcThatThrowsError.
However, in this code:
async function funcThatThrowsError() {
throw new Error('some error');
}
(async () => {
try {
Promise.all([funcThatThrowsError()]);
} catch (error) {
console.log('error caught');
}
}
The catch clause doesn't catch the error. Why is that?
Note that if change the above example to be:
async function funcThatThrowsError() {
throw new Error('some error');
}
(async () => {
Promise.all([
funcThatThrowsError().catch((e) => {
console.log('caught error');
}),
]);
}
Then this catch clause does catch the error.
My questions are:
- Why does it happen?
- Does it mean that when working with
Promise.alli must define a.catch(...)function to every promise I pass toPromise.allotherwise if any promise will throw an exception is won't be caught anywhere and essentially crash my application?
Thanks
答案1
得分: 3
catch 子句未捕获错误。为什么会这样？
你没有等待任何内容，所以你只会捕获到同步错误。如果你想要使用try/catch捕获一个 Promise 拒绝，你必须await该 Promise。Promise.all 创建一个 Promise，所以请await它。
try {
await Promise.all([funcThatThrowsError()]);
} catch (error) {
console.log('捕获到错误');
}
英文:
> The catch clause doesn't catch the error. Why is that?
You aren't awaiting anything, so the only errors you will catch are synchronous errors. If you want to catch a promise rejection with try/catch, you must await that promise. Promise.all creates a promise, so await that.
try {
await Promise.all([funcThatThrowsError()]);
} catch (error) {
console.log('error caught');
}
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