renderHook: Context Provider, state change in child function act() error

[quintonjs]

I have a custom hook that uses a Context Provider for global state management. I am passing a dispatch and data from the state taken from the context inside the hook to a function that will at the end of requesting data from an endpoint dispatch this data coursing a state update inside the context API Provider passed down to the custom hook.

The issue is when I test the custom hook with a wrapper of the Context Provider passed into renderHook() function, I get in the test run the dreaded "act()" error of:

Warning: An update to StoreProvider inside a test was not wrapped in act(...)
      20 |      .then((res) => {
    > 22 |              setLoading(false)
         |              ^
      23 |              dispatch({ 
      24 |                      type: ActionTypesEnum.FETCH_USERS, 
      25 |                      payload: res.data

you can see the full explanation at: https://stackoverflow.com/questions/76157226/react-hooks-testing-library-context-provider-state-change-in-child-function-ac

The useUserSearch Hook:

const useUserSearch = (searchCriteria: string): SearchHookProps => {
  // data from the context and stored in the state
  const { dispatch, state } = useStateContext();
  const { users } = state;
  const [ userData, setUserData ] = useState<UserProps[]>([]);
  const [ loading, setLoading ] = useState<boolean>(false);
  const [ error, setError ] = useState<boolean>(false);
  // connected to the pagination affected by the search
  const [ currentPage, setCurrentPage ] = useState<number>(1)
  const [ totalPages, setTotalPages ] = useState<number>(1)
  const [ totalUserCount, setTotalUserCount ] = useState<number>(0)
  const totalPerPage = 12

  useEffect(() => {
    if (users === null) FetchUsers(dispatch, searchCriteria, setLoading, setError);
  }, [users]);

  useEffect(() => {
      if (searchCriteria.length > 0) FetchUsers(dispatch, searchCriteria, setLoading, setError);
  }, [searchCriteria]);

  return {
    userData,
    totalUserCount,
    setCurrentPage,
    currentPage,
    totalPages,
    loading,
    error,
  }
}

FetchUsers function:

const FetchUsers = (
	dispatch: Dispatch<any>,
	searchCriteria: string,
	setLoading: Dispatch<SetStateAction<boolean>>,
	setError: Dispatch<SetStateAction<boolean>>,) => {
	const { global: { apiUrl } } = AppConfig

	const search = `?q=${encodeURIComponent(searchCriteria)}`

	setLoading(true)
	axios.get(`${apiUrl}/users?q=${search}+in:login+type:user`)
	.then((res) => {
		setLoading(false)
		dispatch({ 
			type: ActionTypesEnum.FETCH_USERS, 
			payload: res.data
		})
	})
	.catch(() => {
		setLoading(false)
		setError(true)
	})
}

StoreProvider:

import React, { useContext, useReducer, useMemo, createContext } from 'react';
import Reducer from '../../Reducers';
import AppConfig from '../../Configs';
import { StateInterface, StoreInterface, ProviderInterface } from '../../Interfaces';

export const initialState: StateInterface = {
  appConfig: AppConfig,
  users: null,
};

export const StoreContext = createContext({
  state: initialState,
} as StoreInterface);

export const useStateContext = () => useContext(StoreContext);

export const StoreProvider = ({ children }: ProviderInterface) => {
  const [state, dispatch] = useReducer(Reducer, initialState);
  const StoreProviderValue = useMemo(() => ({ state, dispatch }), [state, dispatch]);

  return <StoreContext.Provider value={StoreProviderValue}>{children}</StoreContext.Provider>;
};

The Test spec file:

import React from 'react'
import { render, cleanup, waitFor, renderHook, act } from '@testing-library/react'
import axios from 'axios'

import usersMock from '../__mocks__/usersMock'
import { StoreProvider } from '../Providers'
import useUserSearch from './useUserSearch'

jest.mock('axios')
const mockedAxios = axios as jest.Mocked<typeof axios>;

describe('Test that <User />', () => {
  const renderHookComponent = (searchCriteria: string) => {
    const wrapper = ({ children }: any) => <StoreProvider>{children}</StoreProvider>
    const { result, rerender, unmount } = renderHook(() => useUserSearch(searchCriteria), {
      wrapper: wrapper as React.ComponentType<any>
    })
    return { result, rerender, unmount }
  }

  afterEach(() => {
    cleanup()
  })

  it('renders the hook useUserSearch', async () => {
    mockedAxios.get.mockResolvedValue(usersMock);
    const { result } = renderHookComponent('test')

    // await waitFor(() => {
    //   expect(result.current.userData.length).toBe(0)
    // })
  })
})

[mpeyper]

Your imports suggest you are using renderHook from @testing-library/react rather than from this library (@testing-library/react-hooks). It's likely to be an issue with your implementation rather than anything we/they are doing (when to act can be tricky in async hooks), but I'll transfer the issue over there for you for them to confirm.

[dev-frid]

Getting this as well for a hook that sets state in an effect.

Everywhere on the internet tells to use waitForNextUpdate returned by renderHook, but that function was deleted during the migration from @testing-library/react-hooks to @testing-library/react, so I'm stuck with the warning.

There is nothing to act() or waitFor in my case, either, so I'm just stuck with the error...

[MatanBobi]

@dev-frid waitForNextUpdate was too much of a React implementation detail and we couldn't support it in RTL. The option we provide now is to use waitFor and wait for a specific assertion, for example:

await waitFor(() => {
  expect(mockFunction).toHaveBeenCalled();
})

[mpeyper]

It may not help in your case (if there is truely nothing to waitFor, but I have proposed some utilities that replicate some of the old features using the new API in the "will probably never actually be completed" migration guide.

[quintonjs]

Thanks, guys for all your input, I took my eyes away from this thread for a wee while too long. will look through the comments and see what I can do with my code to rectify the issue I have. Thanks all! P.S. will let you know how it goes :)