This allows us to handle common operations such as `useFragment(...).edges.nodes ?? []` where we have a `Phi(MixedReadonly, Array)`. The underlying pattern remains general-purpose and not Relay-specific, and any API that returns transitively "mixed" data (primitives, arrays, plain objects) can benefit from the same type refinement.
ghstack-source-id: 5128310894
Pull Request resolved: https://github.com/facebook/react/pull/30797
Redo of an earlier (pre-OSS) PR to infer types of phi nodes. There are a few pieces to this:
1. Update InferTypes to infer the type of `phi.id.type`, not the unused `phi.type`.
2. Update the algorithm to verify that all the phi types are actually equal, not just have the same kind.
3. Handle circular types by removing the cycle.
However, that reveals another issue: InferMutableRanges currently infers the results of `Store` effects _after_ its fixpoint loop. That was fine when a Store could never occur on a phi (since they wouldn't have a type to get a function signature from). Now though, we can have Store effects occur on phis, and we need to ensure that this correctly updates the mutable range of the phi operands - recursively. See new test that fails without the fixpoint loop.
ghstack-source-id: 2e1b02844d
Pull Request resolved: https://github.com/facebook/react/pull/30796
This is a complex case: we not only need phi type inference but also need to be able infer the union of `MixedReadonly | Array`.
ghstack-source-id: 935088910d
Pull Request resolved: https://github.com/facebook/react/pull/30793
This reverts commit b34b750729.
This hack doesn't play well internally so I'm reverting this for now
(but keeping the compilationMode override). I'll audit the locations we
report later and try to make them more accurate so we won't need this
workaround.
ghstack-source-id: b6be29c11d
Pull Request resolved: https://github.com/facebook/react/pull/30792
Uses the returnIdentifier added in the previous PR to provide a stable identifier for which we can infer a return type for functions, then wires up the equations in InferTypes to infer the type.
ghstack-source-id: 22c0a9ea09
Pull Request resolved: https://github.com/facebook/react/pull/30785
If you have a function expression which _captures_ a mutable value (but does not mutate it), and that function is invoked during render, we infer the invocation as a mutation of the captured value. But in some circumstances we can prove that the captured value cannot have been mutated, and could in theory avoid inferring a mutation.
ghstack-source-id: 47664e48ce
Pull Request resolved: https://github.com/facebook/react/pull/30783
Adds a new Environment config option which allows specifying a function that is called to resolve types of imported modules. The function is passed the name of the imported module (the RHS of the import stmt) and can return a TypeConfig, which is a recursive type of the following form:
* Object of valid identifier keys (or "*" for wildcard) and values that are TypeConfigs
* Function with various properties, whose return type is a TypeConfig
* or a reference to a builtin type using one of a small list (currently Ref, Array, MixedReadonly, Primitive)
Rather than have to eagerly supply all known types (most of which may not be used) when creating the config, this function can do so lazily. During InferTypes we call `getGlobalDeclaration()` to resolve global types. Originally this was just for known react modules, but if the new config option is passed we also call it to see if it can resolve a type. For `import {name} from 'module'` syntax, we first resolve the module type and then call `getPropertyType(moduleType, 'name')` to attempt to retrieve the property of the module (the module would obviously have to be typed as an object type for this to have a chance of yielding a result). If the module type is returned as null, or the property doesn't exist, we fall through to the original checking of whether the name was hook-like.
TODO:
* testing
* cache the results of modules so we don't have to re-parse/install their types on each LoadGlobal of the same module
* decide what to do if the module types are invalid. probably better to fatal rather than bail out, since this would indicate an invalid configuration.
ghstack-source-id: bfdbf67e3d
Pull Request resolved: https://github.com/facebook/react/pull/30771
The fixture from the previous PR was getting inconsistent behavior because of the following:
1. Create an object in a useMemo
2. Create a callback in a useCallback, where the callback captures the object from (1) into a local object, then passes that local object into a logging method. We have to assume the logging method could modify the local object, and transitively, the object from (1).
3. Call the callback during render.
4. Pass the callback to JSX.
We correctly infer that the object from (1) is captured and modified in (2). However, in (4) we transitively freeze the callback. When transitively freezing functions we were previously doing two things: updating our internal abstract model of the program values to reflect the values as being frozen *and* also updating function operands to change their effects to freeze.
As the case above demonstrates, that can clobber over information about real potential mutability. The potential fix here is to only walk our abstract value model to mark values as frozen, but _not_ override operand effects. Conceptually, this is a forward data flow propagation — but walking backward to update effects is pushing information backwards in the algorithm. An alternative would be to mark that data was propagated backwards, and trigger another loop over the CFG to propagate information forward again given the updated effects. But the fix in this PR is more correct.
ghstack-source-id: c05e716f37
Pull Request resolved: https://github.com/facebook/react/pull/30766
This fixture bails out on ValidatePreserveExistingMemo but would ideally memoize since the original memoization is safe. It's trivial to make it pass by commenting out the commented line (`LogEvent.log(() => object)`). I would expect the compiler to infer this as possible mutation of `logData`, since `object` captures a reference to `logData`. But somehow `logData` is getting memoized successfully, but we still infer the callback, `setCurrentIndex`, as having a mutable range that extends to the `setCurrentIndex()` call after the useCallback.
ghstack-source-id: 4f82e34510
Pull Request resolved: https://github.com/facebook/react/pull/30764
Per comments on the new validation pass, this disallows creating JSX (expression/fragment) within a try statement. Developers sometimes use this pattern thinking that they can catch errors during the rendering of the element, without realizing that rendering is lazy. The validation allows us to teach developers about the error boundary pattern.
ghstack-source-id: 0bc722aeae
Pull Request resolved: https://github.com/facebook/react/pull/30725
Addresses a todo from a while back. We now validate environment options when parsing the plugin options, which means we can stop re-parsing/validating in later phases.
ghstack-source-id: b19806e843
Pull Request resolved: https://github.com/facebook/react/pull/30726
This was a pet peeve where our playground could only compile top level
FunctionDeclarations. Just synthesize a fake identifier if it doesn't
have one.
ghstack-source-id: 882483c79c
Pull Request resolved: https://github.com/facebook/react/pull/30729
This PR updates the eslint plugin to report unused opt out directives.
One of the downsides of the opt out directive is that it opts the
component/hook out of compilation forever, even if the underlying issue
was fixed in product code or fixed in the compiler.
ghstack-source-id: 81deb5c11b
Pull Request resolved: https://github.com/facebook/react/pull/30721
This PR updates the babel plugin to continue the compilation pipeline as
normal on components/hooks that have been opted out using a directive.
Instead, we no longer emit the compiled function when the directive is
present.
Previously, we would skip over the entire pipeline. By continuing to
enter the pipeline, we'll be able to detect if there are unused
directives.
The end result is:
- (no change) 'use forget' will always opt into compilation
- (new) 'use no forget' will opt out of compilation but continue to log
errors without throwing them. This means that a Program containing
multiple functions (some of which are opted out) will continue to
compile correctly
ghstack-source-id: 5bd85df2f8
Pull Request resolved: https://github.com/facebook/react/pull/30720
Summary:
The change earlier in this stack makes it less safe to have ref enforcement disabled. This diff enables it by default.
ghstack-source-id: d3ab5f1b28
Pull Request resolved: https://github.com/facebook/react/pull/30716
Summary:
We previously were excessively strict about preventing functions that access refs from being returned--doing so is potentially valid for hooks, because the return value may only be used in an event or effect.
ghstack-source-id: cfa8bb1b54
Pull Request resolved: https://github.com/facebook/react/pull/30724
Summary:
Since we want to make ref-in-render errors enabled by default, we should position those errors at the location of the read. Not only will this be a better experience, but it also aligns the behavior of Forget and Flow.
This PR also cleans up the resulting error messages to not emit implementation details about place values.
ghstack-source-id: 1d11317068
Pull Request resolved: https://github.com/facebook/react/pull/30723
Test Plan:
Documents that useCallback calls interfere with it being ok for refs to escape as part of functions into jsx
ghstack-source-id: a5df427981
Pull Request resolved: https://github.com/facebook/react/pull/30714
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: e8f36ac25e
Pull Request resolved: https://github.com/facebook/react/pull/30713
Per discussion today, adds validation against calling setState "during" passive effects. Basically, it's fine to _schedule_ setState to be called (via a timeout, listener, etc) but generally not recommended to call setState during the effect since that will trigger a cascading render.
This validation is off by default, i'm putting this up for discussion and to experiment with it internally.
ghstack-source-id: 5f385ddab5
Pull Request resolved: https://github.com/facebook/react/pull/30685
Summary:
UseTransition is a builtin hook that returns a stable value, like useState. This PR represents that in Forget, and marks the startTransition function as stable.
ghstack-source-id: 0e76a64f2d
Pull Request resolved: https://github.com/facebook/react/pull/30681
Summary:
In theory, as I understand it, the result of a useRef will never change between renders, because we'll always provide the same ref value consistently. That means that memoization that depends on a ref value will never re-compute, so I think we could not infer it as a dependency in Forget. This diff, however, doesn't do that: it instead allows the validatePreserveExistingMemoizationGuarantees analysis to admit mismatches between explicit dependencies and implicit ones when the implicit dependency is a ref that doesn't exist in source.
ghstack-source-id: 685d859d1e
Pull Request resolved: https://github.com/facebook/react/pull/30679
Summary:
Builds support for macros that are invoked as methods rather than just function calls or jsx.
We now record macros as a schema that represents arbitrary member expressions including wildcards (so we can support, e.g., myMacro.*.foo.bar). When examining PropertyLoads in the macro memoization stage, we build up a map of partially-satisfied macro patterns until we determine that the pattern has been fully satisfied, at which point we treat the result of the PropertyLoad as a macro value.
ghstack-source-id: d78d9ba704
Pull Request resolved: https://github.com/facebook/react/pull/30589
> [!NOTE]
> The `latest` tag is published by default if no tag is specified, which
> is what we had done since the first release of the compiler
In my last PR to auto publish compiler releases I had added the
experimental tag to be used in publishing. However because we had
already previously published to the latest tag (which is non-removable)
this means that the `latest` tag is pinned to an old version. That makes
untagged installs of the compiler default to that old version instead of
whatever is the latest.
This changes the behavior back to what it was before. Since we are still
in the experimental release of the compiler anyway it seems fine to use
the latest tag. When we reach stable, we can update this to only push to
latest for stable releases.
ghstack-source-id: 1809481b45
Pull Request resolved: https://github.com/facebook/react/pull/30666
Previously the compiler would add an import for the specified context
callee even if the context access was not lowered, leading to unused
imports.
This PR tracks if lowering has happened and adds the import only when
necessary.
ghstack-source-id: 6ad794da41
Pull Request resolved: https://github.com/facebook/react/pull/30628
If a value is specified for the LowerContextAccess environment config,
we rewrite the callee from 'useContext' to the specificed value.
This will allow us run an experiment internally.
ghstack-source-id: 00e161b988
Pull Request resolved: https://github.com/facebook/react/pull/30612