使用Axios，aynsc/await和typescript，不知道这个情况

Question

I make a workflows list using axios response but error occurs

Argument of type 'Promise<unknown>' is not assignable to parameter of type 'SetStateAction<WorkflowForReactFlowProps[] | null>'.

this Axios code

export const requestWorkflows = async () => {
  try {
    const response: AxiosResponse = await axios.get(`${baseUrl}/workflows`);
    const workflows = formatWorkflows(response.data.workflows);
    return workflows;
  } catch (error) {
    return error;
  }
};

this state and useEffect code

const [workflows, setWorkflows] =
    useState<Array<WorkflowForReactFlowProps> | null>(null);

  useEffect(() => setWorkflows(requestWorkflows()), []);

why occurs this error? and what is the solution?

Answer 1

An async function always returns a promise. You can see it from here . To make your code work, you need to change these lines:

    const workflows: WorkflowForReactFlowProps[] | null = formatWorkflows(response.data.workflows);

---

useEffect(async () => setWorkflows((await requestWorkflows())), []);