feat(cli): Add W, B, E Vim motions and operator support

[ademuri]

Summary

This change adds support for "Big Word" navigation in Vim mode:
- W: Move forward by big word (space-delimited).
- B: Move backward by big word.
- E: Move to end of big word.

It also supports these motions with operators (d, c):
- dW, cW, dB, cB, dE, cE.                                                                                                             
                                                                                                                                      
Implementation details:                                                                                                               
- Added helper functions findNextBigWordStartInLine, findPrevBigWordStartInLine, findBigWordEndInLine and their cross-line counterpar.
- Added corresponding actions to TextBuffer and vim-buffer-actions.ts.                                                                
- Updated vim.ts to map keys and handle operator motions.                                                                             
- Added comprehensive unit tests in text-buffer.test.ts and integration tests in vim.test.tsx.

This PR also contains fixes to the currently-broken Vim mode tests.

Closes #16768.

How to Validate

Run the Gemini CLI. Enable Vim mode in settings. Type some text, using punctuation in some of the words (e.g. "Here is some!text. Test.txt.bak i^s a word with periods."). Press Esc to enter command mode. Then, use W, E, and B to move the cursor between words. Compare the behavior with the lowercase versions.

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

[gemini-code-assist]

Summary of Changes

Hello @ademuri, 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 significantly enhances the Vim mode experience within the CLI by introducing 'Big Word' navigation (W, B, E) and integrating these motions with delete and change operators. This allows users to move and manipulate text more efficiently, treating sequences of non-whitespace characters as single units, which is particularly useful for code and structured text. The changes involve core text buffer logic, UI integration, and thorough testing to ensure robustness.

Highlights

• Vim "Big Word" Navigation: Introduced 'W', 'B', and 'E' motions for navigating by 'big words' (space-delimited sequences of non-whitespace characters), enhancing text manipulation efficiency.
• Operator Support: Integrated 'W', 'B', and 'E' motions with Vim operators 'd' (delete) and 'c' (change), allowing for commands like 'dW', 'cW', 'dB', 'cB', 'dE', and 'cE'.
• Core Logic Implementation: Added new helper functions (e.g., 'findNextBigWordStartInLine', 'findPrevBigWordStartInLine', 'findBigWordEndInLine', and their cross-line counterparts) to 'text-buffer.ts' to accurately define 'big word' boundaries.
• Text Buffer Actions & Vim Hook Integration: Extended the 'TextBuffer' with new action types and reducer logic for big word movements, deletions, and changes, and updated the 'useVim' hook to map key sequences to these new actions.
• Comprehensive Testing: Included new unit tests for the big word navigation helpers and integration tests for the 'useVim' hook to ensure the correct functionality of all new motions and operators.
• New Configuration Options: Added 'general.disableVimCommandMode' and 'general.vimModeStyle' settings, along with their documentation, to provide users with more control over Vim mode behavior.

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[gemini-code-assist]

Code Review

This pull request adds support for 'Big Word' navigation (W, B, E) in Vim mode, including operator support with 'd' and 'c'. The implementation includes new helper functions for word navigation, corresponding actions in the text buffer, and updates to the Vim hook to handle the new key mappings. The changes are well-tested with new unit and integration tests.

My main feedback is a critical performance issue in the findNextBigWordAcrossLines function, which could lead to UI unresponsiveness on large files with many empty lines due to a nested loop. I've provided a comment with details on the issue and a suggestion for refactoring.

[ademuri]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces support for "Big Word" navigation (W, B, E) and their corresponding operator motions in Vim mode. The implementation includes new helper functions for word navigation, updates to the text buffer actions, and integration into the useVim hook. The changes are well-supported by new unit and integration tests, and the documentation has been updated accordingly. My review identified two high-severity issues in the buffer action implementations: a correctness bug in the dW/cW behavior at the end of a line, and a maintainability concern due to redundant logic in the E motion handler. Addressing these will improve the accuracy of the Vim emulation and the long-term health of the codebase.

[ademuri]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces "Big Word" navigation (W, B, E) and operator support (d, c) to the Vim mode, a valuable enhancement for CLI usability. The implementation is comprehensive, including new helper functions, text buffer actions, and updates to the Vim hook, all supported by new unit and integration tests. I've identified a critical bug in the empty line handling for findNextBigWordAcrossLines and a high-severity issue in findBigWordEndInLine where the logic could be simplified for better maintainability. Addressing these points will solidify this excellent feature addition.

[ademuri]

/gemini review

[gemini-code-assist]

Code Review

This pull request adds support for 'Big Word' navigation (W, B, E) in Vim mode, including operator support with 'd' and 'c'. The implementation includes new helper functions for word navigation, updates to the text buffer actions, and new key mappings in the Vim hook. The documentation and tests have also been updated accordingly. The changes are well-structured and the new feature is a great addition. I've found a couple of correctness issues with the delete/change word forward operations at the end of the buffer, where they behave like delete/change to end of line instead of operating on the word. My review includes suggestions to fix this behavior.

[ademuri]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces support for 'Big Word' navigation (W, B, E) in Vim mode, including operator support (d, c). The implementation adds new helper functions for word finding, extends text buffer actions, and updates the Vim key handling logic. The changes are well-structured and include documentation and test updates. However, I've found a critical copy-paste error that causes the backward 'Big Word' motions (B, dB, cB) to behave like their small-word counterparts, which I've detailed in the comments.

[ademuri]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces "Big Word" navigation (W, B, E) and operator support for Vim mode, which is a great enhancement. The implementation also includes several fixes and refactorings to the existing word navigation logic, improving its correctness and maintainability.

However, I've found a critical copy-paste error in the implementation of the backward "Big Word" operations (B, dB, cB). They are currently using the logic for regular words, which means they don't function as intended. Please see the detailed comments for the fix.

[ademuri]

/gemini review

[gemini-code-assist]

Code Review

This pull request adds support for 'Big Word' navigation (W, B, E) in Vim mode, including operator support. The implementation is thorough, with new helper functions, updated actions, and comprehensive tests. I've identified a couple of high-severity behavioral bugs in the new dw/cw and dW/cW implementations where they don't correctly handle cases when the cursor is on whitespace, deviating from standard Vim behavior. I've provided suggestions to align them with user expectations. The rest of the changes, including documentation updates and other fixes, look good.

[bdmorgan]

Hi @ademuri, thank you so much for your contribution to Gemini CLI! We really appreciate the time and effort you've put into this.

We're making some updates to our contribution process to improve how we track and review changes. Please take a moment to review our recent discussion post: Improving Our Contribution Process & Introducing New Guidelines.

Key Update: Starting January 26, 2026, the Gemini CLI project will require all pull requests to be associated with an existing issue. Any pull requests not linked to an issue by that date will be automatically closed.

Thank you for your understanding and for being a part of our community!

[gemini-cli]

Hi there! Thank you for your contribution to Gemini CLI.

To improve our contribution process and better track changes, we now require all pull requests to be associated with an existing issue, as announced in our recent discussion and as detailed in our CONTRIBUTING.md.

This pull request is being closed because it is not currently linked to an issue. You can easily reopen this PR once you have linked it to an issue.

How to link an issue:
Add a keyword followed by the issue number (e.g., Fixes #123) in the description of your pull request. For more details, see the GitHub Documentation.

Thank you for your understanding and for being a part of our community!

[harshanadim]

Hey @ademuri, this PR already has 'Closes #16768' in the body. You should be able to simply reopen it - the issue link should satisfy the new requirement.

[ademuri]

I am unable to re-open this pull request. Can someone with permissions on the repo do that, or should I open a new pull request?

[harshanadim]

@scidomino would you be able to help reopen this PR for @ademuri ?

[scidomino]

Please update and point your merge to main instead of google-gemini:galzahavi/improve/vim-mode

[scidomino]

I'm seeing some failing tests. Please fix.

[chrstnb]

Build failed: Build process failed with link errors:

21:15:16 [ERROR] ✗ Found 1 invalid link in 1 file.
21:15:16   └─ /docs/cli/vim-mode - invalid link
21:15:16 [ERROR] [starlight-links-validator-integration] An unhandled error occurred while running the "astro:build:done" hook

[ademuri]

Rebased, fixed the failing tests, and removed the link to the non-existent document. Some of the tests failed locally for me, but also failed at main, so I believe they are unrelated.