useTransition: TypeError: Cannot read property 'ref' of null

[leo-petrucci]

I'm on the latest react-spring@^9.0.0-rc.2. When I try to use useTransition I get the following error.

This code has worked before and it does work with 8.x, unfortunately using 8.x breaks other things in my script, so I can't go back to that.

I have no idea what's wrong with it, I haven't even updated React Spring, but it all of a sudden broke and refuses to work. The code is exactly the same as the useTransition example:

  const transitions = useTransition(open, null, {
    from: { transform: `scale(1.5)`, opacity: 0 },
    enter: { transform: `scale(1)`, opacity: 1 },
    leave: { transform: `scale(1.5)`, opacity: 0 },
    unique: true
  });

  return (
    <>
      <div
      >
        {transitions.map(({ item, key, props }) =>
          item &&
            <>
              <animated.div
                style={props}
              >
              </animated.div>
            </>
        )}
      </div>
    </>
  );

What's wrong with it?

[leo-petrucci]

Codesandbox with example
https://codesandbox.io/s/mystifying-kowalevski-zyiqm?file=/src/index.js

[aleclarson]

You're using the old useTransition API. See here: https://aleclarson.github.io/react-spring/v9/breaking-changes/