act cannot detect secondary updates

Do you want to request a feature or report a bug?

bug

What is the current behavior?

If a component performs a second (non user triggered) update, act cannot detect it and warns about the update.

For example, a button is clicked and updates its text. After a second, the button resets and its text reverts to its original state.

https://codesandbox.io/s/6xkyl37x7k?previewwindow=tests

(The reproduction is a bit contrived, but demonstrates the issue.)

What is the expected behavior?

The test runs without warning about being wrapped in act.

Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?

React & React DOM @ 16.8.0

[threepointone]

We are aware of these problems and are working on a solution, sorry about that.

[nbrady-techempower]

Since I’m not sure if the issue marked duplicate will be re-opened, I’ll post this here. We have a library that handles async actions and updates state. A very contrived example of something we need to test for is:

  <input value={count} />
  <button onClick={async () => await someFuncThatChangesCount() } />

How do you test this with act? Currently with react-test-renderer we can do:

  expect(val.props.value).toBe(0);
  await button.props.onClick();
  expect(val.props.value).toBe(1);

This will fail:

  expect(val.props.value).toBe(0);
  act(() => {
    button.props.onClick();
  });
  expect(val.props.value).toBe(1);

And this will continue to warn but because act is receiving a promise

  expect(val.props.value).toBe(0);
  act(async () => {
    await button.props.onClick();
  });
  expect(val.props.value).toBe(1);