fix: #556 guard against undefined window in getScroll

[jeasonnow]

#566

Summary by CodeRabbit

• Bug Fixes

  • 提升了滚动偏移计算在边界情况下的容错性，减少在缺失或无效窗口引用时的异常，增强稳定性与可靠性。

• Tests

  • 新增测试场景，覆盖在缺失或为 null/undefined 的窗口引用下的行为，确保偏移计算返回安全默认值。

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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

Run ID: 1c31915a-775a-4088-b4ce-a92876e1984f

📥 Commits

Reviewing files that changed from the base of the PR and between 9fbe571 and a886974.

📒 Files selected for processing (2)

• src/util.ts
• tests/util.spec.tsx

🚧 Files skipped from review as they are similar to previous changes (1)

• src/util.ts

---

Walkthrough

在 src/util.ts 中，getScroll() 参数扩展为 Window | null | undefined，函数入口对假值返回 0。同时在 tests/util.spec.tsx 为 offset 添加两条断言，覆盖缺失或为 null/undefined 的 window 场景。

Changes

getScroll 空值防护与 offset 测试

Layer / File(s)	Summary
getScroll 参数空值保护与 offset 测试 src/util.ts, tests/util.spec.tsx	getScroll 的参数类型放宽为可空/可未定义并在入口对假值返回 0；为 offset 增加两条测试，验证当 defaultView 或 parentWindow 缺失或为 null/undefined 时返回 {left:0, top:0}。

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Suggested reviewers

• zombieJ

Poem

兔兔在窗边守望，
一行护盾挡风霜，
空值无惧滚动安，
小测验来证光芒，
代码轻跳心欢畅。 🐰

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	标题清楚地总结了主要变更：在 getScroll 函数中添加对未定义 window 的保护逻辑，这正是 PR 的核心改动。
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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src/util.ts

ESLint skipped: missing config or dependency (missing-dependency). The ESLint configuration references a package that is not available in the sandbox.

tests/util.spec.tsx

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[gemini-code-assist]

Code Review

This pull request adds a runtime guard to the getScroll function in src/util.ts to handle cases where the window object is falsy. The review feedback correctly suggests updating the TypeScript signature of getScroll to accept Window | null | undefined to prevent compilation errors under strictNullChecks.

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/util.ts`:
- Around line 11-12: The getScroll function's runtime guard shows w can be
null/undefined but its signature is non-null Window; change the parameter type
of getScroll to accept Window | null | undefined (e.g., getScroll(w: Window |
null | undefined, top?: boolean): number) so the type reflects the runtime
check, and update any call sites (such as where you do const w = doc.defaultView
|| doc.parentWindow; pos.left += getScroll(w)) if necessary to satisfy
TypeScript or overloads.
- Line 12: 为覆盖 getScroll 中的空值保护分支，新增单测到 tests/util.spec.tsx：构造一个元素上下文使
ownerDocument.defaultView 和 ownerDocument.parentWindow 为 null/undefined（例如通过创建一个
mock document 或手动设置 element.ownerDocument.defaultView = undefined /
ownerDocument.parentWindow = null），然后调用 offset(element) 并断言返回值为 { left: 0, top:
0 }；请在测试中同时验证 defaultView 缺失和 parentWindow 缺失两种情况以确保 getScroll 中的 if (!w) return
0 分支被覆盖（定位到 util.ts 中的 getScroll 和 offset 函数）。

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: d18aa098-b7dd-4c8e-872f-f880217da316

📥 Commits

Reviewing files that changed from the base of the PR and between 3ebf65c and 9fbe571.

📒 Files selected for processing (1)

• src/util.ts

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.94%. Comparing base (3ebf65c) to head (a886974).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #567      +/-   ##
==========================================
+ Coverage   98.93%   98.94%   +0.01%     
==========================================
  Files           8        8              
  Lines         188      190       +2     
  Branches       68       69       +1     
==========================================
+ Hits          186      188       +2     
  Misses          2        2              

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