fix(cli): auto-select first autocomplete item

[marius-kilocode]

Summary

• Auto-selects the first autocomplete item when showing suggestions for / commands or @ file mentions
• Adds updateAllSuggestionsAtom() to update all suggestion types atomically and set the selection index correctly
• Fixes test expectations to match the actual behavior (reset to -1 when clearing suggestions)

This makes autocomplete quicker to work with and matches how OpenCode works.

Follow-up to

This is a follow-up to #4708 by @jdm64 with test fixes applied.

Test plan

• Start typing "/" - first command autocomplete item should be selected
• Start typing "@" - first file autocomplete item should be selected
• Run cd cli && npx vitest run src/state/atoms/__tests__/default-selection.test.ts - all 13 tests pass

[changeset-bot]

🦋 Changeset detected

Latest commit: ac644f2

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@kilocode/cli	Patch

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[kiloconnect]

✅ No Issues Found

4 files reviewed | Confidence: 95% | Recommendation: Merge

Review Details

Files:

• .changeset/cli-slash-command-default-selection.md (changeset)
• cli/src/state/atoms/__tests__/default-selection.test.ts (new test file)
• cli/src/state/atoms/ui.ts (new updateAllSuggestionsAtom)
• cli/src/state/hooks/useCommandInput.ts (uses new atom)

Checked: Security, bugs, performance, error handling, state management

Summary:

• The new updateAllSuggestionsAtom correctly handles atomic updates of all suggestion state
• Priority order (fileMention > command > argument) is properly implemented
• Selection index is correctly set to 0 when suggestions exist, -1 when cleared
• Test coverage is comprehensive (13 tests covering all suggestion types and edge cases)
• The approval atom already handles selection reset correctly for new messages
• Code follows established Jotai patterns in the codebase

[kiloconnect]

✅ Previous Issues Addressed

The dependency array issue from my previous review has been resolved:

• Removed unused imports (setSuggestionsAtom, setArgumentSuggestionsAtom, setFileMentionSuggestionsAtom, setFileMentionContextAtom)
• Removed unused useSetAtom declarations
• Updated dependency array to correctly include updateAllSuggestionsAction and extensionState?.customModes

4 files reviewed | Confidence: 95% | Recommendation: Merge

Review Details

Files:

• .changeset/cli-slash-command-default-selection.md ✅
• cli/src/state/atoms/__tests__/default-selection.test.ts ✅ (comprehensive tests covering all suggestion types)
• cli/src/state/atoms/ui.ts ✅ (new updateAllSuggestionsAtom is well-designed)
• cli/src/state/hooks/useCommandInput.ts ✅ (dependency array now correct)

Checked: Security, bugs, performance, error handling

[Drilmo]

Hey @marius-kilocode,

Quick question about this PR: Since merging, we've noticed an issue where slash commands are being ignored in certain situations when using the ask_followup_question tool.

The behavior we're seeing:

• When typing a /command in the followup question input, the command gets ignored
• Instead, the first suggestion is automatically selected and used
• The /commands are not visible/accessible in the followup suggestions menu

Could this change be related? I see in the tests that followupSuggestions intentionally sets selectedIndex to -1 (no selection by design), but wondering if there's a code path where this isn't being respected when the followup suggestions interact with command input?

Let me know if you need more details to reproduce this!

Thanks!

[marius-kilocode]

@Drilmo thanks for flagging. I will check for the root cause.

[marius-kilocode]

@Drilmo found and fixed the issue. #4827 will fix this.