docs(18-03): complete generate route Gemini tests plan

Tasks completed: 2/2
- Gemini provider tests (20 tests)
- Validation and edge case tests (11 tests)

SUMMARY: .planning/phases/18-api-route-tests/18-03-SUMMARY.md

.planning/ROADMAP.md

@@ -238,7 +238,7 @@ Plans:
 Plans:
 - [x] 18-01: File I/O routes (workflow, save-generation)
 - [x] 18-02: LLM route (Google, OpenAI providers)
-- [ ] 18-03: Generate route (Gemini provider)
+- [x] 18-03: Generate route (Gemini provider)
 - [ ] 18-04: Generate route (Replicate, fal.ai providers)
 - [ ] 18-05: Models route (caching, aggregation)
 
@@ -319,7 +319,7 @@ Phases execute in numeric order: 1 → 2 → ... → 14 → 15 → 16 → 17 →
 | 15. Test Infrastructure | v1.2 | 1/1 | Complete | 2026-01-12 |
 | 16. Store Modularization | v1.2 | 1/1 | Complete | 2026-01-12 |
 | 17. Component Tests | v1.2 | 11/11 | Complete | 2026-01-13 |
-| 18. API Route Tests | v1.2 | 2/5 | In progress | - |
+| 18. API Route Tests | v1.2 | 3/5 | In progress | - |
 | 19. Type Refactoring | v1.2 | 0/? | Not started | - |
 | 20. Integration Tests | v1.2 | 0/? | Not started | - |
 | 21. Fix Image Input & Deduplication | v1.2 | 0/? | Not started | - |

.planning/STATE.md

@@ -10,9 +10,9 @@ See: .planning/PROJECT.md (updated 2026-01-09)
 ## Current Position
 
 Phase: 18 of 22 (API Route Tests)
-Plan: 2 of 5 in current phase
+Plan: 3 of 5 in current phase
 Status: In progress
-Last activity: 2026-01-13 - Completed 18-02-PLAN.md
+Last activity: 2026-01-13 - Completed 18-03-PLAN.md
 
 Progress: █████████░ 91%
 
@@ -128,6 +128,6 @@ Recent decisions affecting current work:
 ## Session Continuity
 
 Last session: 2026-01-13
-Stopped at: Completed 18-02-PLAN.md (LLM route tests)
+Stopped at: Completed 18-03-PLAN.md (Generate route Gemini tests)
 Resume file: None
-Next action: Execute Plan 18-03 (run /gsd:execute-plan .planning/phases/18-api-route-tests/18-03-PLAN.md)
+Next action: Execute Plan 18-04 (run /gsd:execute-plan .planning/phases/18-api-route-tests/18-04-PLAN.md)

.planning/phases/18-api-route-tests/18-03-SUMMARY.md

@@ -0,0 +1,91 @@
+---
+phase: 18-api-route-tests
+plan: 03
+subsystem: testing
+tags: [vitest, api-routes, generate, gemini, image-generation]
+
+# Dependency graph
+requires:
+  - phase: 18-02
+    provides: ES6 class mocking pattern with vi.hoisted for GoogleGenAI
+provides:
+  - Generate route tests for Gemini provider (31 tests)
+  - Image generation API testing patterns
+  - Config option testing (aspectRatio, resolution, googleSearch)
+affects: [18-04]
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns: [gemini-generate-content-mocking, image-response-testing]
+
+key-files:
+  created:
+    - src/app/api/generate/__tests__/route.test.ts
+  modified: []
+
+key-decisions:
+  - "Focus on Gemini path only - Replicate/fal.ai tested in 18-04"
+  - "Test model mapping (nano-banana -> gemini-2.5-flash-preview-image-generation)"
+
+patterns-established:
+  - "Image generation response mocking with inlineData structure"
+  - "Config option testing (aspectRatio, resolution, googleSearch)"
+
+issues-created: []
+
+# Metrics
+duration: 5 min
+completed: 2026-01-13
+---
+
+# Phase 18 Plan 03: Generate Route Gemini Tests Summary
+
+**Gemini image generation API tests (31 tests) covering success, config options, validation, and error paths**
+
+## Performance
+
+- **Duration:** 5 min
+- **Started:** 2026-01-13T14:58:00Z
+- **Completed:** 2026-01-13T15:03:00Z
+- **Tasks:** 2
+- **Files modified:** 1
+
+## Accomplishments
+- Created 31 tests for /api/generate route Gemini path
+- Tested all config options (aspectRatio, resolution, googleSearch)
+- Covered input validation (prompt, images, dynamicInputs)
+- Tested provider routing and model mapping
+- Covered error cases (missing key, rate limits, no candidates)
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Create generate route tests for Gemini provider** - `8ae14b4` (test)
+2. **Task 2: Add generate route validation and edge case tests** - `55d95fe` (test)
+
+**Plan metadata:** (this commit)
+
+## Files Created/Modified
+- `src/app/api/generate/__tests__/route.test.ts` - 31 tests covering Gemini provider path
+
+## Decisions Made
+- Focused on Gemini path only, leaving Replicate/fal.ai for 18-04
+- Tested model mapping (nano-banana → gemini-2.5-flash-preview-image-generation)
+
+## Deviations from Plan
+
+None - plan executed exactly as written.
+
+## Issues Encountered
+None - plan executed successfully.
+
+## Next Phase Readiness
+- Gemini generation testing complete
+- Generate route test file ready for Replicate/fal.ai additions in 18-04
+- Ready for 18-04 (Generate route Replicate/fal.ai tests)
+
+---
+*Phase: 18-api-route-tests*
+*Completed: 2026-01-13*