v5.5.1 introduces act-type warning in tests

[curtvict]

Hey! I just wanted to respectfully point out that the v5.5.1 patch might have actually brought along a breaking change, depending on your definition of "breaking change" ;)

We use Mind Renovate to manage our package upgrades automatically. We also use jest-fail-on-console to help keep on top of both, what I call, our "test barf" and to help us be a bit more careful about what non-critical warnings and errors might be raised and subsequently ignored by us during development.

Anyway, when Renovate tried to upgrade to react-select-event to v5.5.1 we started getting a failing build on that branch due to a new act-style warning being thrown... you know the one:

    Warning: An update to WhateverComponentLol inside a test was not wrapped in act(...).

    When testing, code that causes React state updates should be wrapped into act(...):

    act(() => {
      /* fire events that update state */
    });
    /* assert on the output */

... snip ...

I just wanted to point this out because it was unexpected in a patch release and the removal of the act call seems like the entire reason why this patch was released in the first place.

We're on react 17.0.2 and @testing-library/react 12.1.5 for what it's worth which seems to meet this project's devDependencies requirements.

[curtvict]

cc: @romgain

[geoffharcourt]

We are seeing the same issue with React 17.0.2 and @testing-library/react 12.1.5.

[bramdevries]

Do you happen to be able to provide a reproducible test case? The tests in this package still use React 17 and there's no such warning, so it might only be occurring for specific usage?

[antonvialibri1]

@curtvict

We get a similar issue when using Formik together with react-select (React 18, though I don't know if this happens on React 17 too):

import selectEvent from 'react-select-event';
// ...

// In test:
await selectEvent.select(
  select,
  ['TagA', 'TagB', 'TagC']
);
expect(screen.getByText('TagA')).toBeInTheDocument();

The test passes, but we get the annoying act warning:

    Warning: An update to Formik inside a test was not wrapped in act(...).
    
    When testing, code that causes React state updates should be wrapped into act(...):
    
    act(() => {
      /* fire events that update state */
    });
    /* assert on the output */
    

The react-select component we are testing uses Formik under the hood and changes its state using the helpers returned by the Formik's useField hook:

  // In react-select component
  const [field, meta, helpers] = useField(props);

  const handleChange = (newValue) => {
    helpers.setValue(newValue);
  };
  
  // ...
  return (
    <Select
      onChange={handleChange}
      ...
     />
  );

@romgain Is there a solution to this? Thank you!

[antonvialibri1]

@curtvict

I have found a workaround for now, I'm sharing it here so hopefully it helps you as well.

The following code doesn't cause the dreaded act warning:

import selectEvent from 'react-select-event';
import { act, render, screen, waitFor } from '@testing-library/react';
// ...

// In test:
await act(async () => 
  await selectEvent.select(
    select,
    ['TagA', 'TagB', 'TagC']
  );
);
expect(screen.getByText('TagA')).toBeInTheDocument();
expect(screen.getByText('TagB')).toBeInTheDocument();
expect(screen.getByText('TagC')).toBeInTheDocument();

With this code, there's no act warning for me.

☝️ But... The test above didn't pass. I noticed that when you pass an array of options to selectEvent.select like I did with ['TagA', 'TagB', 'TagC'], only the last options ends up being added to the select for some reason (in my case as I'm using React 18, I suppose that it has to do with React 18's Auto Batching, but I'm not sure as I didn't dig deeper).

So what I did was selecting one option at a time, and ended up with this working code:

import selectEvent from 'react-select-event';
import { act, render, screen, waitFor } from '@testing-library/react';
// ...

// In test:
const select = screen.getByRole('textbox', {
  name: /Tags/i
});

// Select one option at a time, reopening the react-select's dropdown each time.
// After all, that's how our users will end up using this component...
selectEvent.openMenu(select);
await act(async () => 
  await selectEvent.select(
    select,
    'TagA'
  );
);

selectEvent.openMenu(select);
await act(async () => 
  await selectEvent.select(
    select,
    'TagB'
  );
);

selectEvent.openMenu(select);
await act(async () => 
  await selectEvent.select(
    select,
    'TagC'
  );
);

expect(screen.getByText('TagA')).toBeInTheDocument();
expect(screen.getByText('TagB')).toBeInTheDocument();
expect(screen.getByText('TagC')).toBeInTheDocument();

A bit of boilerplate, but at least it works and doesn't give any error/warning in my case.

Hope it helps someone who's facing a similar issue.

[nntdias]

@antonvialibri1 in your code you missed the async
await act( ASYNC HERE () => await selectEvent.select( select, 'TagC' ); );

Talking about the warning messages
I tried using the await waitFor(() => selectEvent.select(element, 'value')), and it works here.

[antonvialibri1]

@nntdias Thanks for pointing that out, I updated the code snippets.

[MarkusAbtion]

All my tests are passing, but after using react-select-event I've started seeing the following warning in unrelated tests:

console.error
      Warning: The current testing environment is not configured to support act(...)

[huarmenta]

This works but prints "Warning: An update to Select inside a test was not wrapped in act(...)."

await selectEvent.select(element, 'label');

This works but prints "Warning: You called act(async () => ...) without await. This could lead to unexpected testing behaviour, interleaving multiple act calls and mixing their scopes. You should - await act(async () => ...);"

act(async () => {
  await selectEvent.select(element, 'label');
});

This does NOT work at all

await act(async () => {
  await selectEvent.select(element, 'label');
});

This does NOT work too (with or without the waitFor)

await waitFor(async () => {
  await selectEvent.select(element, 'label');
});

Not even opening the select before selecting works.

Any help here?

[dennisoelkers]

We are seeing the same problems and need to change lots of tests in order to be able to update. Is this really necessary or a regression that we can expect to get fixed at some point?

[tgsoverly]

This worked for me:

  await act(() => selectEvent.select(selectWrapper, 'Name'));