---
phase: 04-heatmap-interaction
plan: 02
subsystem: testing
tags: [vitest, d3, heatmap, click-navigation, project-filter, typescript]

requires:
  - phase: 04-heatmap-interaction
    provides: Click navigation and project filter dropdown implementation
provides:
  - Vitest test coverage for cell click callback and URL construction
  - Vitest test coverage for project filter dropdown behavior
affects: [polish]

tech-stack:
  added: []
  patterns: [vi.stubGlobal fetch mocking, window.location capture via Object.defineProperty, vi.waitFor async DOM assertions]

key-files:
  created:
    - assets/test/interaction.test.ts
    - assets/test/filter.test.ts
  modified: []

key-decisions:
  - "No architectural decisions -- test-only plan following established patterns"

patterns-established:
  - "Async init() testing: use vi.waitFor() to wait for fetch resolution before asserting DOM state"
  - "Location capture: Object.defineProperty(window, 'location') with getter/setter for href testing"

requirements-completed: [TEST-04]

duration: 1min
completed: 2026-04-08
---

# Phase 4 Plan 2: Interaction Tests Summary

**Vitest tests for click navigation (cell callback, URL daterange, project filter in URL) and filter dropdown (rendering, fetch params, empty state)**

## Performance

- **Duration:** 1 min
- **Started:** 2026-04-08T13:33:12Z
- **Completed:** 2026-04-08T13:34:39Z
- **Tasks:** 2
- **Files modified:** 2

## Accomplishments
- 7 click navigation tests covering onCellClick callback, daterange URL construction, project filter in URL, and fallback URL
- 9 filter dropdown tests covering rendering, option population, fetch URL params, re-render, accessibility, and filtered empty state
- All 26 unique tests pass (52 including symlink duplicates), existing 10 heatmap tests unbroken

## Task Commits

Each task was committed atomically:

1. **Task 1: Click navigation tests** - `4b87dbf` (test)
2. **Task 2: Filter dropdown tests** - `b50972a` (test)

## Files Created/Modified
- `assets/test/interaction.test.ts` - Click navigation tests: onCellClick callback, init() URL construction with daterange and project filter
- `assets/test/filter.test.ts` - Filter dropdown tests: rendering, option population, fetch with project param, re-render, empty state message

## Decisions Made
None - followed plan as specified.

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered
None

## User Setup Required
None - no external service configuration required.

## Next Phase Readiness
- Full test coverage for interaction features (click navigation + project filter)
- Ready for polish phase

---
*Phase: 04-heatmap-interaction*
*Completed: 2026-04-08*