所以你会在控制台日志中看到以下警告: Warning: An effect function must not return anything besides a function, which is used for clean-up. It looks like you wrote useEffect(async () => ...) or returned a Promise. Instead, write the async function inside your effect and call it immediately...
Since async functions inside useEffect are quite common, rendering a component containing such a hook should wait for the component updates to have finished (with a small timeout).👍 26 ️ 10 Member kentcdodds commented May 13, 2020 Hi @fabb, There's no way for React Testing Library...
正确使用 async 函数和 useEffect 是一个常见的问题,因为在 useEffect 中直接使用 async 函数会导致一些问题。这是因为 useEffect 函数本身不能直接返回 Promise。下面是一种正确使用 async 函数和 useEffect 的方法: 代码语言:txt 复制 import React, { useEffect } from 'react'; function MyComponent() { useEffe...
Now the Hook is back to returning players data and the main useEffect() function is back to returning nothing. Instead, we've defined the fetchTopPlayers() inner function that we immediately call. We make fetchTopPlayers() an async function so that we can use await within it. I gotta ad...
How does useEffect support async...await... Even the callback function of useEffect cannot use async...await, so I use it directly. Approach 1: Create an asynchronous function (async...await method), and then execute the function.
Since useEffect does not support returning a promise, we use an IIFE (Immediately Invoked Function Expression) to initiate the async function and call it right away. The empty dependency array [] ensures that the hook only runs once when the component mounts. If data is null (i.e. while ...
Until the stable release of React, you'll need to wrap the waitForUpdate call with act`: await act(() => waitForNextUpdate()); This no longer produces the warning for the first update, but, and I'm not sure if this is intentional or not, but your useEffect does not specify any de...
你能告诉我你得到了什么样的错误，因为我没有看到一个问题，这样做，在同一个useEffect？它只是变得有...
Since the React useEffect callback function cannot be async, you can do either of the following: Create a Self-Invoking Anonymous Function; Create a Nested Named Function. Create a Self-Invoking Anonymous Function You can simply create a self-invoking anonymous function inside the useEffect hook...
You cannot directly make the callback function supplied to theuseEffecthookasyncbecause: asyncfunctions implicitly return a promise, and; useEffectexpects its callback to either return nothing or aclean-up function. When you attempt to makeuseEffect's callbackasync, you will see the following warning...