[compiler] Exclude refs and ref values from having mutable ranges #30713
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Summary: Refs, as stable values that the rules of react around mutability do not apply to, currently are treated as having mutable ranges, and through aliasing, this can extend the mutable range for other values and disrupt good memoization for those values. This PR excludes refs and their .current values from having mutable ranges. Note that this is unsafe if ref access is allowed in render: if a mutable value is assigned to ref.current and then ref.current is mutated later, we won't realize that the original mutable value's range extends. [ghstack-poisoned]
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This was referenced Aug 15, 2024
… ranges" Summary: Refs, as stable values that the rules of react around mutability do not apply to, currently are treated as having mutable ranges, and through aliasing, this can extend the mutable range for other values and disrupt good memoization for those values. This PR excludes refs and their .current values from having mutable ranges. Note that this is unsafe if ref access is allowed in render: if a mutable value is assigned to ref.current and then ref.current is mutated later, we won't realize that the original mutable value's range extends. [ghstack-poisoned]
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| !isUseRefType(id) && | ||
| !isRefValueType(id), |
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maybe add a helper for this combination?
| @@ -2,7 +2,7 @@ | |||
| ## Input | |||
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| ```javascript | |||
| // @enablePreserveExistingMemoizationGuarantees | |||
| // @enablePreserveExistingMemoizationGuarantees @validateRefAccessDuringRender | |||
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We're going to need to enable @validateRefAccessDuringRender by default to make this change safe. Obviously if you're using React Compiler with Flow, then Flow would catch the ref accesses, but we need to ensure this is just as safe without Flow.
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ah i see you did this later in the stack, sweet
josephsavona
approved these changes
Aug 15, 2024
… ranges" Summary: Refs, as stable values that the rules of react around mutability do not apply to, currently are treated as having mutable ranges, and through aliasing, this can extend the mutable range for other values and disrupt good memoization for those values. This PR excludes refs and their .current values from having mutable ranges. Note that this is unsafe if ref access is allowed in render: if a mutable value is assigned to ref.current and then ref.current is mutated later, we won't realize that the original mutable value's range extends. [ghstack-poisoned]
This was referenced Aug 16, 2024
… ranges" Summary: Refs, as stable values that the rules of react around mutability do not apply to, currently are treated as having mutable ranges, and through aliasing, this can extend the mutable range for other values and disrupt good memoization for those values. This PR excludes refs and their .current values from having mutable ranges. Note that this is unsafe if ref access is allowed in render: if a mutable value is assigned to ref.current and then ref.current is mutated later, we won't realize that the original mutable value's range extends. [ghstack-poisoned]
… ranges" Summary: Refs, as stable values that the rules of react around mutability do not apply to, currently are treated as having mutable ranges, and through aliasing, this can extend the mutable range for other values and disrupt good memoization for those values. This PR excludes refs and their .current values from having mutable ranges. Note that this is unsafe if ref access is allowed in render: if a mutable value is assigned to ref.current and then ref.current is mutated later, we won't realize that the original mutable value's range extends. [ghstack-poisoned]
mvitousek
added a commit
that referenced
this pull request
Aug 16, 2024
Summary: Refs, as stable values that the rules of react around mutability do not apply to, currently are treated as having mutable ranges, and through aliasing, this can extend the mutable range for other values and disrupt good memoization for those values. This PR excludes refs and their .current values from having mutable ranges. Note that this is unsafe if ref access is allowed in render: if a mutable value is assigned to ref.current and then ref.current is mutated later, we won't realize that the original mutable value's range extends. ghstack-source-id: e8f36ac25e2c9aadb0bf13bd8142e4593ee9f984 Pull Request resolved: #30713
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Stack from ghstack (oldest at bottom):
Summary:
Refs, as stable values that the rules of react around mutability do not apply to, currently are treated as having mutable ranges, and through aliasing, this can extend the mutable range for other values and disrupt good memoization for those values. This PR excludes refs and their .current values from having mutable ranges.
Note that this is unsafe if ref access is allowed in render: if a mutable value is assigned to ref.current and then ref.current is mutated later, we won't realize that the original mutable value's range extends.