glitter: make hover work, and add it to every interactable region

[m4ttheweric]

What

Two things, and the second turned out to matter more than the first.

Hover was never reaching the board at all

mouseView.View() in ui/internal/session/session.go overwrote MouseMode unconditionally on every frame, pinning every session view to MouseModeCellMotion. Per bubbletea v2's own docs, CellMotion reports movement ONLY while a button is held; AllMotion is what reports movement with no button pressed. So the terminal was never asked to send hover motion, Mission.mouseMotion never fired, and every hover treatment in the board was unreachable in any terminal.

That predates this branch. The file rows, top-bar segments, diff lines and foldout rows have all had hover rendering and passing tests since the board shipped, and none of it has ever been visible to a user. The tests passed because they call render functions with hovered=true directly, never through the event path. Confirmed empirically by the owner across Ghostty, flock and Terminal.app: no hover anywhere.

The decorator now applies CellMotion as a DEFAULT only when the inner view left MouseMode at its zero value, and Mission.View() asks for AllMotion explicitly. A test now asserts the mission view reports the mode it needs, which is the test that would have caught this.

Worth knowing about the fix: MouseModeNone is bubbletea's zero value, so "never set a mode" and "actively wants mouse off" are indistinguishable. Reading the zero as "didn't ask" is safe only because this decorator exclusively wraps views that already opted into Options.Mouse. That reasoning is in the code.

Seven regions that had no hover treatment

An audit of hitTest found fifteen click targets with hover on six. Of the nine without, one was already covered and one is genuinely inert, leaving seven:

Region	Treatment
Commit button	Brightens to PinkSoft, and only when it is actually pressable
History tab	HoverBg behind its own half of the strip
Filter box	Border brightens to GutterHoverBar
Summary box	Same
Description box	Same
Stash strip	HoverBg across the strip
Undo chip	HoverBg on the chip only, not its line

No new theme tokens. GutterHoverBar is Pink blended halfway to the background and already serves as the diff gutter's hover preview, so it sits between rest and focus. The three text boxes deliberately do not reuse Pink: a hover matching the focus treatment reads as already-focused.

Two deliberate exclusions:

• A disabled commit button does not hover. It renders clickable but is inert without a summary, so hover stays a promise that something will happen.
• The Changes tab does not hover. tabsHit returns an inert hit for the left half, since Changes is always the active tab. Hovering something that cannot respond would be a lie.

The tradeoff this accepts

AllMotion streams an event per cell of pointer movement and can take over text selection in some terminals. The picker already accepts that cost for a full-screen view (picker.go:829), the board is full-screen and hover-driven, and CellMotion structurally cannot deliver idle hover in bubbletea v2. So it is the only way to have this feature at all.

Verification

• go vet ./... clean; go test -count=1 ./... all 9 packages ok, in both parallel and -p 1 modes.
• bun run test:pty 4 pass. bash scripts/repo-purity.sh ok.
• Driven by hand in a real terminal, which is the only check that could have caught the mouse-mode bug and the reason it is now a unit test too.

Every hover treatment is a pure color swap on an already-fixed-width fragment, and each test asserts the hovered and unhovered forms occupy identical rows and widths. That matters specifically because the modal's mouse hit-test is a hand-rolled parallel copy of the box layout, so a hover that shifted a cell would misplace clicks rather than merely look wrong.

Tests written first. Six of the seven hover tests were confirmed red by forcing each render function's hover argument false; the seventh asserts state rather than rendering, so it was confirmed red by removing the mouseMotion switch arms, the only edit that can actually break it.

Checked by hand rather than trusted to the suite: all seven new hover fields are cleared at the top of mouseMotion before the switch, so a highlight cannot survive the pointer moving away.

🤖 Generated with Claude Code

Summary by CodeRabbit

• New Features

  • Added hover feedback throughout the mission sidebar, including tabs, filters, commit controls, stash, history, summary, and undo actions.
  • Hover states now update as the pointer moves, without requiring a mouse button press.
  • Disabled commit controls remain visually inactive when hovered.

• Bug Fixes

  • Preserved explicitly selected mouse interaction modes while enabling cell-motion tracking where needed.
  • Improved hover highlighting consistency and focus behavior across sidebar controls.

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Reviewing files that changed from the base of the PR and between bc00ebf and 955eac6.

📒 Files selected for processing (2)

• ui/internal/session/options_internal_test.go
• ui/internal/session/session.go

📝 Walkthrough

Walkthrough

The session mouse wrapper now preserves explicit mouse modes. The mission view enables all-motion input, tracks sidebar hover targets, and applies hover-specific rendering with focused and disabled-state precedence.

Changes

Mission hover interaction

Layer / File(s)	Summary
Mouse mode preservation ui/internal/session/session.go, ui/internal/session/options_internal_test.go	mouseView defaults only unset modes to MouseModeCellMotion. Explicit modes such as MouseModeAllMotion remain unchanged. Tests cover both behaviors.
Mission hover rendering ui/internal/views/mission/mission.go, ui/internal/views/mission/changes.go, ui/internal/views/mission/render_test.go	The mission view tracks hover state for sidebar regions, updates state from mouse-motion hit results, and passes it to renderers. Hover colors apply to tabs, filters, commit controls, stash, and undo while preserving focus, disabled, clipping, and layout behavior. Tests cover the seven hit regions and rendering rules.

Priority: ⬇️ Low

Estimated code review effort: 3 (Moderate) | ~25 minutes

Change: Feature

Sequence Diagram(s)

sequenceDiagram
  participant BubbleTea
  participant Mission
  participant MissionRenderers
  BubbleTea->>Mission: deliver all-motion mouse event
  Mission->>Mission: clear sidebar hover flags
  Mission->>Mission: set the matching hover flag
  Mission->>MissionRenderers: pass hover state
  MissionRenderers-->>Mission: render highlighted control

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Merge Risk: 🔵 Low · up to bc00e

Mouse-disabled Mission sessions can still enable hover motion. Preserve the disabled-mouse option before merging.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	Docstring coverage is 88.89% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 36 functions across 5 files.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: adding hover feedback to interactable regions in the glitter UI. It is concise and directly related to the changeset.

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Inline comments:
In `@ui/internal/views/mission/mission.go`:
- Line 633: Update the disabled-session path in wireMouse so Options.Mouse=false
forces tea.MouseModeNone, preventing Mission.View from enabling mouse motion;
preserve the existing enabled-session behavior. Add an assertion covering
wireMouse(allMotionStubView{}, Options{}) and verify the returned wrapper uses
MouseModeNone.

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Configuration used: defaults

Review profile: CHILL

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Run ID: 207f189e-ac76-4d90-879b-5a4674111376

📥 Commits

Reviewing files that changed from the base of the PR and between 0d13c42 and bc00ebf.

📒 Files selected for processing (5)

• ui/internal/session/options_internal_test.go
• ui/internal/session/session.go
• ui/internal/views/mission/changes.go
• ui/internal/views/mission/mission.go
• ui/internal/views/mission/render_test.go

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