componentDidUpdate inexplicably not firing after render in a single component

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

Bug

What is the current behavior?

componentDidUpdate not firing after render in one lone component. No idea how to recreate in a sandbox.

What is the expected behavior?

componentDidUpdate fires after every render

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

React@16.11 & React@16.12 affected in Electron@6

---

I’m tracking when componentDidUpdate and render are firing with log statements.

The log statements in componentDidUpdate do not fire after render. I have used breakpoints to confirm this isn’t a timing issue.

My code (stripped down) is below. This is the output of the logging. Sometimes I’ll get componentDidUpdate to fire, but inconsistently and it’s never the final thing, a RENDER always shows up in my logs last, never UPDATE.

class MyWrapper extends React.PureComponent {
  render() {
  const { buttonDefinitions } = this.props;
    return (
      <InfoProvider
        render={infoProps => {
          return (
            <MyMenu
              {...{ buttonDefinitions, infoProps }}
            />
          );
        }}
      />
    );
  }
}

class MyMenu extends React.Component {
  componentDidUpdate() {
    log.warn('UPDATE');
  }

  render() {
    log.warn('RENDER');
    const { buttonDefinitions } = this.props;
    return (
      <MenuWrapper>
        {buttonDefinitions.map(buttonDef => (
          <MyButton {...buttonDef} />
        ))}
      </MenuWrapper>
    );
  }
}

[bvaughn]

If render is called one or more times, componentDidUpdate should call at least once, right?

Not necessarily true, although if the DOM is being modified then the commit phase has run and it should definitely be called in that case.

The profound weirdness of this issue has me hesitant to dive straight into trying to create a repro since I haven’t the faintest clue why this is the only component out of several hundred that I’m seeing this behavior with.

I’d say this is a necessary next step in order for someone to actually look into the issue 🙂 It’s probably going to be easier for you to start stripping things out of your app than it would be for us to speculate about all of the things that could be inside an app we’ve never seen.

[bvaughn]

Ah, interesting! 😄 Thanks for the follow up. Glad you got it sorted out.