React-testing-library: Suppressing react-dom act warning

[robcaldecottvelo]

Since upgrading to @testing-library/react 9.1.x we are seeing the following warning in nearly all our tests:

It looks like you're using a version of react-dom that supports the "act" function, but not an awaitable version of "act" which you will need. Please upgrade to at least [email protected] to remove this warning.

However, we are not yet in a position to update react and react-dom to 16.9.0 as this causes issues with some 3rd-party components we are consuming.

Is there any way to suppress this warning? It feels like something we should be able to opt out of.

[kentcdodds]

Do this in your setup file:

// hack until we can upgrade to [email protected]
const originalError = console.error
beforeAll(() => {
  // this is here to silence a warning temporarily
  // we'll fix it in the next exercise
  jest.spyOn(console, 'error').mockImplementation((...args) => {
    if (typeof args[0] === 'string' && args[0].includes('Please upgrade to at least [email protected]')) {
      return
    }
    return originalError.call(console, args)
  })
})

afterAll(() => {
  console.error.mockRestore()
})

That should do it for you :) I don't think that I want to add special logic here for opting-out. I can be convinced otherwise though I guess.

[kentcdodds]

For now I'll close this.

[jktravis]

Hi. I have a similar problem with the latest versions of both React and RTL. I extracted out a minimal representation of this component and left only two tests: one doesn't show the error, the other does.

Am I using this wrong? Or is there still an issue with React?

Warning: An update to FacilitySelector 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 */

This ensures that you're testing the behavior the user would see in the browser. Learn more at https://fb.me/react-wrap-tests-with-act
    in FacilitySelector

Edit: Not sure if this belongs here, or elsewhere. Sorry.

[kentcdodds]

Hi @jktravis, it's likely that something is happening after your test finishes which is triggering the warning. Please provide some additional details (and try to make your example a bit smaller) on https://spectrum.chat/testing-library/help-react

[getdave]

Do this in your setup file:

After a bit of tinkering, I worked out I had to go with something a little more manual as spyOn() wasn't working with my version of Jest. Hopefully, the below saves someone some time!

const originalError = global.console.error;
beforeAll(() => {
    global.console.error = jest.fn((...args) => {
        if (typeof args[0] === 'string' && args[0].includes('Please upgrade to at least [email protected]')) {
          return
        }
        return originalError.call(console, args)
    });
});

afterAll(() => {
    global.console.error.mockRestore();
});