fix(ui): prevent empty tool-group border stubs after filtering

[Aaxhirrr]

Summary

Fixes a UI rendering bug where tool-related blocks could collapse into an orphan bottom border line after state transitions (notably plan approval and hidden tool-error flows).

The change ensures ToolGroupMessage only renders a standalone closing border when the item is an explicit empty closing slice (tools: []) used for static/pending border continuity.

Details

Root cause:

• ToolGroupMessage could end up with visibleToolCalls.length === 0 after filtering (low error verbosity, plan-mode filtering, confirming/in-progress hidden paths).
• Previous logic could still render a closing border when borderBottom=true, producing the “empty border stub”.

Fix:

• Updated the empty-render guard in ToolGroupMessage:
  • If all visible tools are filtered out, return null.
  • Exception: allow rendering only for explicit closing slices (allToolCalls.length === 0) with borderBottom=true.

Validation hardening (new tests):

• Hidden low-verbosity internal error with borderBottom=true renders no fragment.
• Plan-mode filtered write tool with borderBottom=true renders no fragment.
• Confirming-only group with borderBottom=true renders no fragment.
• Transition case (visible -> fully filtered) leaves no stub.
• Stress case (50 filtered hidden errors + 1 visible tool) keeps visible output and hides filtered tools.
• Explicit closing slice still renders (normal and very narrow width) to preserve split static/pending continuity.

Related Issues

Fixes #21685

How to Validate

1. Run targeted tests:

   • npm run test --workspace @google/gemini-cli -- src/ui/components/messages/ToolGroupMessage.test.tsx
   • Expected: all tests pass (including new edge/extreme cases).

2. Run nearby integration surface:

   • npm run test --workspace @google/gemini-cli -- src/ui/components/MainContent.test.tsx
   • Expected: pass; split static/pending tool-group behavior remains intact.

3. Run typecheck:

   • npm run typecheck --workspace @google/gemini-cli
   • Expected: no type errors.

4. Manual interactive verification:

   • Set ui.errorVerbosity to low.
   • Reproduce tool failure flow and plan approval transition (Ask User / Exit Plan Mode path).
   • Expected: no orphan bottom-border fragments; either full content appears or block cleanly disappears.
   • Switch ui.errorVerbosity to full.
   • Expected: tool error content remains visible; no border stubs.

Pre-Merge Checklist

• Updated relevant documentation and README (if needed)
• Added/updated tests (if needed)
• Noted breaking changes (if any)
• Validated on required platforms/methods:
  • MacOS
    • npm run
    • npx
    • Docker
    • Podman
    • Seatbelt
  • Windows
    • npm run
    • npx
    • Docker
  • Linux
    • npm run
    • npx
    • Docker

[Aaxhirrr]

/gemini review

Edit: Was expecting Gemini bot feedback, but it looks like the bot isn’t attached on this PR from my side.

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses a visual glitch in the UI where tool-related blocks would sometimes display an unwanted bottom border after their content was filtered or hidden. The changes ensure that these empty border fragments are correctly suppressed, improving the cleanliness and consistency of the user interface during dynamic state changes, while preserving necessary visual cues for specific tool group transitions.

Highlights

• UI Rendering Fix: Resolved a UI bug where ToolGroupMessage could render orphan bottom border lines after tool filtering or state transitions (e.g., plan approval, hidden tool errors).
• Rendering Logic Update: Modified ToolGroupMessage to only render a closing border when it's an explicit empty closing slice (tools: []) for static/pending border continuity, preventing rendering when all tools are filtered out.
• Test Coverage Enhancement: Added comprehensive new test cases to validate the fix across various scenarios, including low verbosity errors, plan-mode filtering, confirming-only groups, transition cases, and stress tests.

Changelog

• packages/cli/src/ui/components/messages/ToolGroupMessage.test.tsx
  • Added lowVerbositySettings mock for testing.
  • Introduced new test cases to verify that bottom-border fragments are not rendered when all tools are filtered out due to low verbosity settings.
  • Added a test to ensure explicit closing slices for split static/pending groups still render.
  • Included tests to confirm no border fragments are rendered when plan-mode tools or confirming-only tools are filtered out.
  • Added a test for the transition case from visible to fully filtered tools, ensuring no border stub remains.
  • Implemented a stress test to verify visible tools render correctly even with many filtered tools.
  • Added a test to confirm explicit closing slices render correctly even at very narrow terminal widths.
• packages/cli/src/ui/components/messages/ToolGroupMessage.tsx
  • Modified the conditional rendering logic to prevent ToolGroupMessage from emitting standalone border fragments when all tools are filtered out.
  • Introduced isExplicitClosingSlice to specifically allow rendering for empty tool groups (allToolCalls.length === 0) that are intended as closing slices for border continuity.

Activity

• No specific activity (comments, reviews, progress updates) has been recorded for this pull request yet.

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[gemini-code-assist]

Code Review

This pull request effectively addresses the UI rendering bug where empty tool-group border stubs could appear after filtering. The updated logic in ToolGroupMessage.tsx correctly distinguishes between genuinely empty tool groups and explicit closing slices, ensuring that standalone bottom borders are only rendered when intended for static/pending continuity. The addition of comprehensive test cases in ToolGroupMessage.test.tsx provides excellent coverage for various filtering scenarios, including low verbosity errors, plan-mode tools, confirming tools, and transition states, which significantly hardens the validation of this fix. The changes are well-implemented and directly resolve the reported issue.

[gemini-code-assist]

Code Review

This pull request effectively resolves a UI rendering bug that caused orphan borders to appear when tool groups became empty after filtering. The proposed change correctly adjusts the rendering logic to prevent this, while carefully preserving the intended behavior for explicit closing borders. The fix is well-supported by a comprehensive suite of new unit tests that cover various edge cases and state transitions, confirming the robustness of the solution. The changes are well-contained and I have not identified any issues.

[jacob314]

[jacob314]

[jacob314]

/patch preview

[jacob314]

/patch stable

[github-actions]

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[github-actions]

🚀 [Step 1/4] Patch workflow(s) waiting for approval!

📋 Details:

• Channels: stable
• Commit: b00d7c88ad8d7c9f14eba4a66f04c91c85bf5ffd
• Workflows Created: 1

⏳ Status: The patch creation workflow has been triggered and is waiting for deployment approval. Please visit the specific workflow links below and approve the runs.

🔗 Track Progress:

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• View patch workflow history
• This trigger workflow run