fix: guard missing React version export

[nrps9909]

Summary

• avoid crashing while loading rc-util/es/ref when a bundler's React interop object does not expose version
• preserve the existing React 19 check when version is available
• add a regression test for the missing-export shape

Why

rc-util@5.44.4 started reading version.split(...) at module scope, and the same unguarded read remains in the current @rc-component/util source. In the Vite production-build cases reported in #647 and #783, the React named export can be undefined, so importing ref.js throws before the application renders. Treating a missing version as an unknown version keeps the React 18-compatible path and prevents the module-load failure. A legacy rc-util release would require a maintainer backport to 5.x.

Verification — September 17, 2026

Rebased onto current master (c241125); signed/GitHub-Verified head: 3863469d708a5a5be1b34e93148c10572fae31a4.

• Full suite: 31 suites, 198 tests passed; 1 test skipped.
• TypeScript, ESM/CJS/declaration build, focused ESLint (0 errors), Prettier and diff checks passed.
• GitHub signatures and changed-file blobs were checked against the local branch.
• Includes upstream fix: resolve pre-existing test failures on master #815, which fixes the prior pickAttrs and React-17 fallback test failures.
• Upstream CI: ✅ test currently action_required. A maintainer must approve the fork workflow before it can run.
• Vercel preview still requires upstream team authorization.

AI assistance disclosure

Codex assisted with implementation, conflict resolution, regression tests, and validation.

[vercel]

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: da1677a1-1d37-49d5-9dfa-f5742312c915

📥 Commits

Reviewing files that changed from the base of the PR and between d1045f4 and a42c5a7.

📒 Files selected for processing (2)

• src/ref.ts
• tests/ref-version.test.ts

Included review availability: Your plan provides up to 4 included reviews per hour; 3 remain after this review.

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Walkthrough

本次变更为 ReactMajorVersion 增加可选链访问，并新增测试。version 为 undefined 时，模块加载不再因调用 split 抛出异常。

Changes

React version 缺失处理

Layer / File(s)	Summary
version 防护与加载测试 src/ref.ts, tests/ref-version.test.ts	ReactMajorVersion 使用 version?.split('.')[0]。新增 Jest 测试，验证 React 未导出 version 时加载 src/ref 不会抛出异常。

Estimated code review effort: 1 (Trivial) | ~5 minutes

Merge Risk: ⚪ Minimal · up to a42c5

The change prevents an import-time crash when React lacks a version export while preserving the existing behavior when the version is available. No actionable merge-blocking risk remains after normal checks and review.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	变更满足问题 #647 的主要目标。代码在 React 版本导出为 undefined 时避免调用 split，并新增回归测试验证模块加载不会抛出异常。
Out of Scope Changes check	✅ Passed	所有变更均围绕问题 #647，包括 React 版本检测修复和对应回归测试。未发现无关或超出范围的代码变更。
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 2…
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	标题“fix: guard missing React version export”准确概括了主要变更，即防止缺少 React 版本导出时发生崩溃。标题简洁且具体。

✨ Finishing Touches 💡 1

🛠️ Fix failing CI checks 💡

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests

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_{小兔守着 version 门，
缺失时也不惊慌。
可选链轻轻探路，
ref 模块安稳加载。
测试敲响绿色铃，
代码继续向前跑。}

_{Comment @coderabbitai help to get the list of available commands.}

[yoyo837]

CI failed.

[nrps9909]

Rebased onto current master (c241125); signed/GitHub-Verified head: 3863469d708a5a5be1b34e93148c10572fae31a4.

• Full suite: 31 suites, 198 tests passed; 1 test skipped.
• TypeScript, ESM/CJS/declaration build, focused ESLint (0 errors), Prettier and diff checks passed.
• GitHub signatures and changed-file blobs were checked against the local branch.
• Includes upstream fix: resolve pre-existing test failures on master #815, which fixes the prior pickAttrs and React-17 fallback test failures.
• Upstream CI: ✅ test currently action_required. A maintainer must approve the fork workflow before it can run.
• Vercel preview still requires upstream team authorization.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.77%. Comparing base (c241125) to head (3863469).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #810   +/-   ##
=======================================
  Coverage   86.77%   86.77%           
=======================================
  Files          41       41           
  Lines        1096     1096           
  Branches      397      382   -15     
=======================================
  Hits          951      951           
  Misses        143      143           
  Partials        2        2           

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