PureComponent not working with setState inside interval

[davegri]

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

Report a possible bug

What is the current behavior?

Calling setState (with new state) insider a setInterval callback does not cause a re-render when using PureComponent. I've tried logging the next and previous state inside shouldComponentUpdate and they show up as identical even though they shouldn't be.

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://jsfiddle.net or similar (template: https://jsfiddle.net/reactjs/69z2wepo/).

What is the expected behavior?

Component should update

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

Latest version

[gaearon]

Thanks for the report. Unfortunately it is not very helpful without a code example.
This is why the issue template includes this line:

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://jsfiddle.net or similar (template: https://jsfiddle.net/reactjs/69z2wepo/).

It is likely that you're mutating the state somewhere. However without code it's impossible to tell.
If you don't provide an example we'll have to close the issue because it is not actionable.

[davegri]

So when trying to reproduce the bug in a sandbox I realized that we were doing this.state.count++ which was causing the mutation. thanks for the hint!

would it be possible to add warning for state mutations similar to redux-immutable-state-invariant? this was a pretty tough one for us to debug.

cheers

[gaearon]

There was an attempt in #8265 but the author didn't continue working on it.

[aweary]

Closing since PureComponent + setState seem to be working fine 👍

would it be possible to add warning for state mutations similar to redux-immutable-state-invariant? this was a pretty tough one for us to debug.

@davegri you can track #2272 for updates on that