fix(react): avoid some unexpected __SetAttribute when attribute value is undefined

[hzy]

Summary

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

Summary by CodeRabbit

• Bug Fixes

  • Prevented unexpected attribute operations when passing undefined as a prop in JSX elements.

• New Features

  • Added a test to ensure no unnecessary patch is emitted when hydrating elements with undefined props.

• Refactor

  • Updated the serialization format for snapshot values from arrays to objects with string keys to improve consistency.

• Tests

  • Adjusted existing test snapshots to reflect the new serialization format for values.
  • Added coverage for scenarios involving undefined and null props during hydration.

[changeset-bot]

🦋 Changeset detected

Latest commit: a96b7de

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@lynx-js/react	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[coderabbitai]

Walkthrough

The changes update the serialization format of the values property in snapshot data from arrays to objects with string indices, affecting type declarations, serialization logic, and test snapshots. Additional test coverage is introduced to verify no patches are emitted for undefined attributes in hydration scenarios.

Changes

Files/Group	Change Summary
.changeset/calm-lies-dig.md	Added a changeset documenting a patch for handling undefined attributes in JSX for @lynx-js/react.
packages/react/runtime/src/snapshot.ts	Changed values type from array to object in SerializedSnapshotInstance; updated serialization logic.
packages/react/runtime/test/lifecycle/reload.test.jsx	Updated test snapshots: values fields now objects with string keys instead of arrays.
packages/react/runtime/test/snapshot/event.test.jsx packages/react/runtime/test/snapshot/ref.test.jsx	Updated test snapshots: values now objects with string keys instead of arrays in event/ref tests.
packages/react/runtime/test/preact.test.jsx	Added test to ensure no patch is emitted when hydrating with undefined raw-text prop.
packages/react/testing-library/src/tests/act.test.jsx	Updated test snapshots: values fields changed from arrays to objects with string keys.

Sequence Diagram(s)

sequenceDiagram
    participant TestSuite
    participant SnapshotInstance
    participant SerializedSnapshot

    TestSuite->>SnapshotInstance: Call toJSON()
    SnapshotInstance->>SnapshotInstance: Convert __values array to object with string keys
    SnapshotInstance-->>SerializedSnapshot: Return object with values as Record<string, unknown>
    SerializedSnapshot-->>TestSuite: Used in test snapshot comparison

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Suggested labels

platform:Web

Poem

In the meadow of code, a change takes root,
Arrays to objects—snapshots now astute!
No more patches for undefined in sight,
Hydration’s calm, all tests pass bright.
With stringy keys and bunny glee,
Serialization hops ahead, as happy as can be! 🐇

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📜 Recent review details

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Review profile: CHILL
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📥 Commits

Reviewing files that changed from the base of the PR and between a96b7de and 124a125.

📒 Files selected for processing (7)

• .changeset/calm-lies-dig.md (1 hunks)
• packages/react/runtime/__test__/lifecycle/reload.test.jsx (6 hunks)
• packages/react/runtime/__test__/preact.test.jsx (1 hunks)
• packages/react/runtime/__test__/snapshot/event.test.jsx (2 hunks)
• packages/react/runtime/__test__/snapshot/ref.test.jsx (3 hunks)
• packages/react/runtime/src/snapshot.ts (2 hunks)
• packages/react/testing-library/src/__tests__/act.test.jsx (2 hunks)

✅ Files skipped from review due to trivial changes (3)

• packages/react/testing-library/src/tests/act.test.jsx
• packages/react/runtime/test/snapshot/event.test.jsx
• packages/react/runtime/test/snapshot/ref.test.jsx

🚧 Files skipped from review as they are similar to previous changes (4)

• packages/react/runtime/test/preact.test.jsx
• packages/react/runtime/src/snapshot.ts
• packages/react/runtime/test/lifecycle/reload.test.jsx
• .changeset/calm-lies-dig.md

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[Copilot]

Pull Request Overview

This PR fixes an issue where undefined attribute values in React components were causing unexpected __SetAttribute operations during serialization. The change modifies how snapshot values are serialized by converting arrays to objects, which ensures undefined values are preserved during JSON serialization and prevents unnecessary attribute operations.

Key changes:

• Changed values type from any[] to Record<string, unknown> in SerializedSnapshotInstance interface
• Modified serialization logic to convert array values to objects using Object.assign
• Added test case to verify undefined values don't cause patches

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/react/runtime/src/snapshot.ts	Updates type definition and serialization logic to convert array values to objects
packages/react/runtime/test/snapshot/ref.test.jsx	Updates test expectations to reflect new object-based values format
packages/react/runtime/test/snapshot/event.test.jsx	Updates test expectations to reflect new object-based values format
packages/react/runtime/test/preact.test.jsx	Adds new test case for undefined attribute handling
packages/react/runtime/test/lifecycle/reload.test.jsx	Updates test expectations to reflect new object-based values format
.changeset/calm-lies-dig.md	Documents the fix for undefined attribute handling

[codspeed-hq]

CodSpeed Performance Report

Merging #1311 will not alter performance

_{Comparing hzy:p/hzy/perf-0718 (124a125) with main (ec7228f)}

Summary

✅ 10 untouched benchmarks

[relativeci]

React Example

#3093 Bundle Size — 234.46KiB (~+0.01%).

124a125(current) vs ec7228f main#3063(baseline)

Bundle metrics   1 change

	Current #3093	Baseline #3063
Initial JS	0B	0B
Initial CSS	0B	0B
Cache Invalidation	37.83%	0%
Chunks	0	0
Assets	4	4
Modules	157	157
Duplicate Modules	63	63
Duplicate Code	45.88%	45.88%
Packages	2	2
Duplicate Packages	0	0

Bundle size by type   1 change 1 regression

	Current #3093	Baseline #3063
IMG	145.76KiB	145.76KiB
Other	88.7KiB (+0.02%)	88.68KiB

Bundle analysis report Branch hzy:p/hzy/perf-0718 Project dashboard

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[relativeci]

Web Explorer

#3083 Bundle Size — 304.59KiB (0%).

124a125(current) vs ec7228f main#3054(baseline)

Bundle metrics   1 change

	Current #3083	Baseline #3054
Initial JS	140.65KiB	140.65KiB
Initial CSS	31.83KiB	31.83KiB
Cache Invalidation	0%	0%
Chunks	4	4
Assets	5	5
Modules	205(+0.49%)	204
Duplicate Modules	17	17
Duplicate Code	4.22%	4.22%
Packages	3	3
Duplicate Packages	0	0

Bundle size by type  no changes

	Current #3083	Baseline #3054
JS	221.88KiB	221.88KiB
Other	50.89KiB	50.89KiB
CSS	31.83KiB	31.83KiB

Bundle analysis report Branch hzy:p/hzy/perf-0718 Project dashboard

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