fix(agent): restore input blocker on Chrome fatal error

[cRAN-cg]

Summary

Fixes #22159

The McpToolInvocation.execute() method in mcpToolWrapper.ts had a bug where resumeInputBlocker() was never called when a fatal Chrome connection error ("Could not connect to Chrome") was thrown mid-execution of an interactive tool (click, fill, hover, etc.). This left the input blocker overlay permanently suspended (pointer-events: none), causing the tab to appear controlled but not actually blocking user input.

Changes

• mcpToolWrapper.ts: Refactored the execute() method to use try...finally. suspendInputBlocker() is called before the try block (resource acquisition), and resumeInputBlocker() is called in the finally block with .catch(() => {}) to ensure cleanup on all code paths — success, non-fatal error, and fatal Chrome disconnection. This replaces the previous two separate resume call sites with a single one in finally.

• mcpToolWrapper.test.ts: Added two new test cases:

  1. Chrome fatal error still resumes the input blocker via finally
  2. Chrome fatal error + resume failure (double fault) — original error propagates, resume failure is swallowed by .catch(() => {})

Test plan

• Existing tests pass (suspend/resume on success, non-fatal error paths)
• New test: fatal Chrome error resumes blocker
• New test: fatal error + resume failure doesn't mask original error
• Pre-commit hooks pass (prettier, eslint, lint-staged)
• npm run preflight (CI will validate)

[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 resolves a critical issue where the browser's input blocker could remain permanently suspended following a fatal Chrome connection error during interactive tool execution. By restructuring the input blocker's resumption logic with a try...finally block, the system now reliably restores the blocker, significantly improving the robustness and user experience of interactive browser automation. Comprehensive new tests have been introduced to validate this fix under various error conditions.

Highlights

• Input Blocker Resumption Logic: Refactored the McpToolInvocation.execute() method to use a try...finally block, ensuring resumeInputBlocker() is always called. This guarantees the input blocker is restored even during fatal Chrome connection errors, preventing the tab from remaining frozen.
• Test Coverage Enhancement: Added two new test cases to mcpToolWrapper.test.ts to specifically cover scenarios where the input blocker is resumed after a fatal Chrome connection error, including cases where the resume operation itself might fail.

Changelog

• packages/core/src/agents/browser/mcpToolWrapper.test.ts
  • Added a test case to verify that the input blocker resumes even when a fatal Chrome connection error is thrown.
  • Added a test case to confirm that the original fatal error propagates even if the blocker resumption itself fails.
• packages/core/src/agents/browser/mcpToolWrapper.ts
  • Moved the suspendInputBlocker call to occur before the try block.
  • Removed redundant resumeInputBlocker calls from the success and error paths.
  • Introduced a finally block to ensure resumeInputBlocker is called on all execution paths, including when fatal errors are thrown.

Activity

• Existing tests for suspend/resume on success and non-fatal error paths have passed.
• New test cases for fatal Chrome errors and resume failures have been added and are passing.
• Pre-commit hooks (prettier, eslint, lint-staged) have passed.
• The pull request is awaiting CI validation (npm run preflight).

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[gemini-code-assist]

Code Review

This pull request addresses an issue where the input blocker was not restored after a fatal Chrome connection error. The change refactors mcpToolWrapper.ts to use a try...finally block, ensuring resumeInputBlocker is called on all execution paths. New test cases have been added to mcpToolWrapper.test.ts to verify this behavior, including handling of fatal errors and double-fault scenarios where the resume action also fails. The changes appear correct and address the described issue.

[cRAN-cg]

/assign

[gemini-cli]

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