[compiler] Fixes to enableTreatRefLikeIdentifiersAsRefs #34000
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We added the `@enableTreatRefLikeIdentifiersAsRefs` feature a while back but never enabled it. Since then we've continued to see examples that motivate this mode, so here we're fixing it up to prepare to enable by default. It now works as follows:
* If we find a property load or property store where both a) the object's name is ref-like (`ref` or `-Ref`) and b) the property is `current`, we infer the object itself as a ref and the value of the property as a ref value. Originally the feature only detected property loads, not stores.
* Inferred refs are not considered stable (this is a change from the original implementation). The only way to get a stable ref is by calling `useRef()`. We've seen issues with assuming refs are stable.
With this change, cases like the following now correctly error:
```js
function Foo(props) {
const fooRef = props.fooRef;
fooRef.current = true;
^^^^^^^^^^^^^^ cannot modify ref in render
}
```
josephsavona
commented
Jul 25, 2025
| @@ -1211,6 +1211,8 @@ addObject(BUILTIN_SHAPES, BuiltInRefValueId, [ | |||
| ['*', {kind: 'Object', shapeId: BuiltInRefValueId}], | |||
| ]); | |||
|
|
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| addObject(BUILTIN_SHAPES, ReanimatedSharedValueId, []); | |||
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Without this i got errors trying to resolve properties, because we have a shape id defined for reanimated but no shape definition. I'm not sure how we didn't run into that error before but it seems like it easily could have occurred.
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Note that the error was an invariant which i don't think we report in eslint, so the compiler may have just been silently failing for folks using reanimated
This was referenced Jul 25, 2025
poteto
approved these changes
Jul 29, 2025
| @@ -10,7 +10,7 @@ function Foo() { | |||
|
|
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| const onClick = useCallback(() => { | |||
| ref.current?.click(); | |||
| }, []); | |||
| }, [ref]); | |||
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out of curiosity what was this for?
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same as below, the ref could change over time
| const customRef = useCustomRef(); | ||
| let t0; | ||
| if ($[0] === Symbol.for("react.memo_cache_sentinel")) { | ||
| if ($[0] !== customRef) { |
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I get that this is functionally equivalent since the box identity never changes, but shouldn't refs be ignored as dependencies for memo blocks?
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we don't know that useCustomRef() returns a stable ref. it could create two refs and state, and toggle between which ref it returns on each render
github-actions bot
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this pull request
Jul 29, 2025
We added the `@enableTreatRefLikeIdentifiersAsRefs` feature a while back
but never enabled it. Since then we've continued to see examples that
motivate this mode, so here we're fixing it up to prepare to enable by
default. It now works as follows:
* If we find a property load or property store where both a) the
object's name is ref-like (`ref` or `-Ref`) and b) the property is
`current`, we infer the object itself as a ref and the value of the
property as a ref value. Originally the feature only detected property
loads, not stores.
* Inferred refs are not considered stable (this is a change from the
original implementation). The only way to get a stable ref is by calling
`useRef()`. We've seen issues with assuming refs are stable.
With this change, cases like the following now correctly error:
```js
function Foo(props) {
const fooRef = props.fooRef;
fooRef.current = true;
^^^^^^^^^^^^^^ cannot modify ref in render
}
```
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/34000).
* #34027
* #34026
* #34025
* #34024
* #34005
* #34006
* #34004
* #34003
* __->__ #34000
DiffTrain build for [85bbe39](85bbe39)
github-actions bot
pushed a commit
that referenced
this pull request
Jul 29, 2025
We added the `@enableTreatRefLikeIdentifiersAsRefs` feature a while back
but never enabled it. Since then we've continued to see examples that
motivate this mode, so here we're fixing it up to prepare to enable by
default. It now works as follows:
* If we find a property load or property store where both a) the
object's name is ref-like (`ref` or `-Ref`) and b) the property is
`current`, we infer the object itself as a ref and the value of the
property as a ref value. Originally the feature only detected property
loads, not stores.
* Inferred refs are not considered stable (this is a change from the
original implementation). The only way to get a stable ref is by calling
`useRef()`. We've seen issues with assuming refs are stable.
With this change, cases like the following now correctly error:
```js
function Foo(props) {
const fooRef = props.fooRef;
fooRef.current = true;
^^^^^^^^^^^^^^ cannot modify ref in render
}
```
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/34000).
* #34027
* #34026
* #34025
* #34024
* #34005
* #34006
* #34004
* #34003
* __->__ #34000
DiffTrain build for [85bbe39](85bbe39)
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We added the
@enableTreatRefLikeIdentifiersAsRefsfeature a while back but never enabled it. Since then we've continued to see examples that motivate this mode, so here we're fixing it up to prepare to enable by default. It now works as follows:refor-Ref) and b) the property iscurrent, we infer the object itself as a ref and the value of the property as a ref value. Originally the feature only detected property loads, not stores.useRef(). We've seen issues with assuming refs are stable.With this change, cases like the following now correctly error:
Stack created with Sapling. Best reviewed with ReviewStack.