useCombobox appears to be incompatible with react compiler

[MattyBalaam]

If I try and type in an input on combobox then the value does not update. If I add 'use no memo'; to the file to opt out then it works as expected.

I have created a minimal reproduction: https://stackblitz.com/edit/vitejs-vite-jzpospa2?file=src%2FApp.jsx

[MattyBalaam]

Screen.Recording.2025-05-08.at.08.52.55.mov

[silviuaavram]

Hey @MattyBalaam I'm not aware of the react compiler, can your provide more info and maybe suggest improvements? Thanks!

[MattyBalaam]

It is the “auto memo” feature React has been building for a few years and is now in RC: https://react.dev/blog/2025/04/21/react-compiler-rc

You can see it in use on the linked minimal reproduction

[MattyBalaam]

I have tried to take a look with Downshift installed locally. Adding the new lint rule threw up some warnings:

/Users/matthewbalaam/downshift/src/hooks/useCombobox/index.js
   96:5  warning  React Hook useEffect has a missing dependency: 'props'. Either include it or remove the dependency array                                                                                                                                                                                          react-hooks/exhaustive-deps
  117:4  warning  React Hook useMemo has unnecessary dependencies: 'inputRef.current', 'menuRef.current', and 'toggleButtonRef.current'. Either exclude them or remove the dependency array. Mutable values like 'menuRef.current' aren't valid dependencies because mutating them doesn't re-render the component  react-hooks/exhaustive-deps

/Users/matthewbalaam/downshift/src/hooks/useSelect/index.js
  136:7  warning  React Hook useMemo has unnecessary dependencies: 'menuRef.current' and 'toggleButtonRef.current'. Either exclude them or remove the dependency array. Mutable values like 'menuRef.current' aren't valid dependencies because mutating them doesn't re-render the component  react-hooks/exhaustive-deps

✖ 3 problems (0 errors, 3 warnings)

[phryneas]

Yeah, I just updated downshift a few majors, and it has actually gotten a lot worse :/

The pattern of const latestState = latest.current.state to keep functions like getInputProps stable references means that the compiler will never re-execute getInputProps - because it assumes that it will be side-effect free.
Right now, downshift is violating the rules of React left and right :/

That means the component will never see any new state on re-execution.

I would like to offer a PR to get this Compiler-compatible, but it would mean ripping quite a lot of stuff out. Would you be willing to accept such a PR?

[silviuaavram]

fixed by #1690