fix(Popper): add null & connected checks for document

[kmcfaul]

What: Closes #12255

Adds a fallback to window.document for getDocumentElement.ts and adds isConnected checks for useIsomorphicLayoutEffect before createPopper is called.

[coderabbitai]

Walkthrough

Updated Popper utility system to add defensive checks: enhanced getDocumentElement with fallback handling for missing document references, and added isReferenceConnected helper to verify DOM element connectivity before Popper initialization.

Changes

Cohort / File(s)	Summary
Popper DOM utilities and hooks packages/react-core/src/helpers/Popper/thirdparty/popper-core/dom-utils/getDocumentElement.ts, packages/react-core/src/helpers/Popper/thirdparty/react-popper/usePopper.ts	Added fallback for missing document reference and new DOM connection check (isReferenceConnected) to prevent Popper initialization with detached elements.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main changes: adding null checks for document in getDocumentElement and connected checks for elements in usePopper.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[patternfly-build]

Preview: https://pf-react-pr-12284.surge.sh

A11y report: https://pf-react-pr-12284-a11y.surge.sh

[coderabbitai]

🧹 Nitpick comments (1)

packages/react-core/src/helpers/Popper/thirdparty/react-popper/usePopper.ts (1)

128-130: Please add a regression test for detached→connected transitions.

Lines 128-130 correctly gate initialization on isConnected; adding a test for reconnection flow would lock in this behavior and prevent regressions.

If you want, I can draft the exact test cases for referenceElement and popperElement connectivity transitions.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@packages/react-core/src/helpers/Popper/thirdparty/react-popper/usePopper.ts`
around lines 128 - 130, Add a regression test for the detached→connected
transition that verifies usePopper initializes once elements reattach: mount a
component that uses usePopper with a referenceElement and popperElement
initially not connected (e.g., created but not appended to document), assert
that initialization does not run while isReferenceConnected(referenceElement) or
popperElement.isConnected are false, then append both elements to document (or
reattach the reference) and assert the hook creates/initializes the popper (spy
or assert popperInstance/instance creation or that the popper update method was
called). Target the usePopper hook and the gating checks isReferenceConnected,
referenceElement, and popperElement to ensure the reconnection flow is covered
and prevents regressions.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@packages/react-core/src/helpers/Popper/thirdparty/react-popper/usePopper.ts`:
- Around line 128-130: Add a regression test for the detached→connected
transition that verifies usePopper initializes once elements reattach: mount a
component that uses usePopper with a referenceElement and popperElement
initially not connected (e.g., created but not appended to document), assert
that initialization does not run while isReferenceConnected(referenceElement) or
popperElement.isConnected are false, then append both elements to document (or
reattach the reference) and assert the hook creates/initializes the popper (spy
or assert popperInstance/instance creation or that the popper update method was
called). Target the usePopper hook and the gating checks isReferenceConnected,
referenceElement, and popperElement to ensure the reconnection flow is covered
and prevents regressions.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: e3de51a5-434e-4d7a-8da2-2302dc4e4f66

📥 Commits

Reviewing files that changed from the base of the PR and between 641c888 and 316ffdc.

📒 Files selected for processing (2)

• packages/react-core/src/helpers/Popper/thirdparty/popper-core/dom-utils/getDocumentElement.ts
• packages/react-core/src/helpers/Popper/thirdparty/react-popper/usePopper.ts

[dlabaj]

LGTM!