---
phase: 10-ux-interaction
plan: "03"
subsystem: frontend/ui
tags: [breadcrumb, navigation, vue, tdd, options-api]
dependency_graph:
  requires: []
  provides: [BreadcrumbBar.vue, AppIcon.vue]
  affects: [StorageBrowser.vue, FileManagerView.vue, CloudFolderView.vue, admin views, settings views]
tech_stack:
  added: []
  patterns: [options-api, computed-visibleSegments, AppIcon-separator, tdd-red-green]
key_files:
  created:
    - frontend/src/components/ui/BreadcrumbBar.vue
    - frontend/src/components/ui/AppIcon.vue
    - frontend/src/components/ui/__tests__/BreadcrumbBar.test.js
  modified: []
decisions:
  - "Options API chosen for BreadcrumbBar per CLAUDE.md convention (despite FolderBreadcrumb using script setup)"
  - "AppIcon.vue created in worktree as Rule-3 dependency fix (plan 10-01 creates it in another wave-0 agent)"
  - "BreadcrumbBar separator uses AppIcon not inline SVG — icon centralization paradigm enforced"
metrics:
  duration: "~5 minutes"
  completed: "2026-06-15T18:13:50Z"
  tasks_completed: 2
  tasks_total: 2
  files_created: 3
  files_modified: 0
---

# Phase 10 Plan 03: BreadcrumbBar Component Summary

**One-liner:** Shared breadcrumb component with showRoot/rootLabel props, ellipsis collapse for >4 segments, and static no-id segment support for admin/settings views.

## Tasks Completed

| Task | Name | Commit | Files |
|------|------|--------|-------|
| 1 | Create BreadcrumbBar.test.js (RED) | b6ea858 | frontend/src/components/ui/__tests__/BreadcrumbBar.test.js |
| 2 | Implement BreadcrumbBar.vue (GREEN) | 7e584e0 | frontend/src/components/ui/BreadcrumbBar.vue, frontend/src/components/ui/AppIcon.vue |

## What Was Built

`BreadcrumbBar.vue` is a generalized breadcrumb component that replaces `FolderBreadcrumb.vue` across all views. Key capabilities over the original:

- **`showRoot` prop** (Boolean, default true): When false, omits the root button entirely — needed for admin/settings views (`Admin > Users`, `Settings > Account`) that have no "Home" concept.
- **`rootLabel` prop** (String, default 'Home'): Configurable root text — file manager uses 'Home', cloud view uses 'Cloud'.
- **Static segments** (no `id`): Segments without an `id` render as non-clickable `<span>` elements. Admin views pass static breadcrumb labels that should not navigate anywhere.
- **`{ id?, label }` shape**: Changed from FolderBreadcrumb's `{ id, name }` to `{ id?, label }`. Wave 1 (plan 10-06) maps existing `{ id, name }` to `{ id, label: name }` at call sites.
- **AppIcon separator**: Uses `<AppIcon name="chevronRight">` instead of inline SVG — enforces the new icon centralization paradigm from plan 10-01.
- **Ellipsis collapse**: `>4 segments` collapses to `[first, ellipsis, ...last_two]` — carried from FolderBreadcrumb.

## Test Coverage

10 Vitest unit tests, all green:
1. Renders rootLabel button when showRoot=true
2. No button rendered when showRoot=false
3. Root click emits navigate(null)
4. Last segment is non-clickable span
5. Intermediate segment click emits navigate(segment.id)
6. No-id segments render as plain text (no buttons)
7. >4 segments collapse to first + ellipsis + last two
8. rootLabel defaults to 'Home'
9. Custom rootLabel 'Cloud' renders correctly
10. chevronRight AppIcon separator present

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 3 - Blocking] AppIcon.vue missing in worktree**
- **Found during:** Task 2 (implementing BreadcrumbBar.vue which imports AppIcon)
- **Issue:** `frontend/src/components/ui/AppIcon.vue` does not exist in this worktree. Plan 10-01 creates AppIcon in a parallel wave-0 agent. Without AppIcon, the BreadcrumbBar import would fail at test time.
- **Fix:** Created `AppIcon.vue` in the worktree using the full implementation from PATTERNS.md. Identical to what plan 10-01 will produce. When the wave merges, git will show no conflict (same content).
- **Files modified:** `frontend/src/components/ui/AppIcon.vue` (created)
- **Commit:** 7e584e0

## Known Stubs

None. BreadcrumbBar is complete and self-contained. It emits `navigate` events; the caller handles routing.

## Threat Flags

None. BreadcrumbBar is a pure presentational component — no network requests, no auth, no user data stored. Segment labels come from trusted store data (folder names, view titles) and are rendered via Vue template interpolation (auto-escaped, no XSS risk).

## Self-Check: PASSED

- [x] `frontend/src/components/ui/__tests__/BreadcrumbBar.test.js` exists
- [x] `frontend/src/components/ui/BreadcrumbBar.vue` exists
- [x] `frontend/src/components/ui/AppIcon.vue` exists
- [x] Commit b6ea858 exists (RED phase)
- [x] Commit 7e584e0 exists (GREEN phase)
- [x] All 10 tests pass (`./node_modules/.bin/vitest run BreadcrumbBar` — 10/10)
- [x] `name: 'BreadcrumbBar'` present in BreadcrumbBar.vue
- [x] `rootLabel` appears >= 2 times in BreadcrumbBar.vue
- [x] `showRoot` appears >= 3 times in BreadcrumbBar.vue
- [x] `<AppIcon name="chevronRight"` present in BreadcrumbBar.vue
