[compiler] Patch for reactive refs in inferred effect dependencies

[mofeiZ]

Inferred effect dependencies and inlined jsx (both experimental features) rely on InferReactivePlaces to determine their dependencies.

Since adding type inference for phi nodes (#30796), we have been incorrectly inferring stable-typed value blocks (e.g. props.cond ? setState1 : setState2) as non-reactive. This fix patches InferReactivePlaces instead of adding a new pass since we want non-reactivity propagated correctly

[mofeiZ]

This is what we want -- note that ref is reactive as it comes from props

[mofeiZ]

derived is now correctly added as a dependency. Prior to this PR, this deps array was empty (playground link)

[Copilot]

Pull Request Overview

This PR fixes the inference of reactive refs in experimental inferred effect dependencies and inline JSX transforms after type inference for phi nodes was added. Key changes include:

• Updating the inline JSX transform expected output to handle both children and ref dependencies.
• Adding new fixtures and expectation files for reactive ref ternary operations.
• Enhancing the reactive places inference by introducing a StableSidemap to account for stable-typed value blocks, and updating HIR utility functions to support stable type container checks.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/inline-jsx-transform.expect.md	Updated expected output to validate new dependency checks for children and ref.
compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/infer-effect-dependencies/reactive-ref-ternary.js	Added fixture for testing reactive refs in ternary operations.
compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/infer-effect-dependencies/reactive-ref-ternary.expect.md	Updated expected output accordingly.
compiler/packages/babel-plugin-react-compiler/src/Inference/InferReactivePlaces.ts	Revised inference to incorporate stable type checks using a new StableSidemap helper.
compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts	Added functions to detect stable type containers and evaluate stability for hook calls.

Comments suppressed due to low confidence (2)

compiler/packages/babel-plugin-react-compiler/src/Inference/InferReactivePlaces.ts:39

• [nitpick] Consider renaming 'StableSidemap' to 'StableSideMap' for improved readability and consistency.

class StableSidemap {

compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts:1742

• [nitpick] Consider renaming 'type_' to a more conventional name if possible, unless the underscore is necessary to avoid conflicts with reserved words.

const type_ = id.type;

[mvitousek]

Thanks for the walkthrough! Adding some more documentation would be good (especially that the key is that stability isn't propagated through phis) but this looks great.