react/compiler/packages/babel-plugin-react-compiler
Joseph Savona 4082b0e7d3
[compiler] Detect known incompatible libraries (#34027)
A few libraries are known to be incompatible with memoization, whether
manually via `useMemo()` or via React Compiler. This puts us in a tricky
situation. On the one hand, we understand that these libraries were
developed prior to our documenting the [Rules of
React](https://react.dev/reference/rules), and their designs were the
result of trying to deliver a great experience for their users and
balance multiple priorities around DX, performance, etc. At the same
time, using these libraries with memoization — and in particular with
automatic memoization via React Compiler — can break apps by causing the
components using these APIs not to update. Concretely, the APIs have in
common that they return a function which returns different values over
time, but where the function itself does not change. Memoizing the
result on the identity of the function will mean that the value never
changes. Developers reasonable interpret this as "React Compiler broke
my code".

Of course, the best solution is to work with developers of these
libraries to address the root cause, and we're doing that. We've
previously discussed this situation with both of the respective
libraries:
* React Hook Form:
https://github.com/react-hook-form/react-hook-form/issues/11910#issuecomment-2135608761
* TanStack Table:
https://github.com/facebook/react/issues/33057#issuecomment-2840600158
and https://github.com/TanStack/table/issues/5567

In the meantime we need to make sure that React Compiler can work out of
the box as much as possible. This means teaching it about popular
libraries that cannot be memoized. We also can't silently skip
compilation, as this confuses users, so we need these error messages to
be visible to users. To that end, this PR adds:

* A flag to mark functions/hooks as incompatible
* Validation against use of such functions
* A default type provider to provide declarations for two
known-incompatible libraries

Note that Mobx is also incompatible, but the `observable()` function is
called outside of the component itself, so the compiler cannot currently
detect it. We may add validation for such APIs in the future.

Again, we really empathize with the developers of these libraries. We've
tried to word the error message non-judgementally, because we get that
it's hard! We're open to feedback about the error message, please let us
know.
2025-08-28 16:21:15 -07:00
..
scripts
src [compiler] Detect known incompatible libraries (#34027) 2025-08-28 16:21:15 -07:00
jest.config.js
package.json
README.md
tsconfig.json
tsup.config.ts

babel-plugin-react-compiler

React Compiler is a compiler that optimizes React applications, ensuring that only the minimal parts of components and hooks will re-render when state changes. The compiler also validates that components and hooks follow the Rules of React.

This package contains the React Compiler Babel plugin use in projects that make use of Babel. You can find instructions for using this plugin here: https://react.dev/learn/react-compiler