docs(18-02): complete LLM route tests plan

Tasks completed: 2/2
- Google provider tests (9 tests)
- OpenAI provider tests (9 tests)

SUMMARY: .planning/phases/18-api-route-tests/18-02-SUMMARY.md

.planning/ROADMAP.md

@@ -237,7 +237,7 @@ Plans:
 
 Plans:
 - [x] 18-01: File I/O routes (workflow, save-generation)
-- [ ] 18-02: LLM route (Google, OpenAI providers)
+- [x] 18-02: LLM route (Google, OpenAI providers)
 - [ ] 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 | 1/5 | In progress | - |
+| 18. API Route Tests | v1.2 | 2/5 | 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: 1 of 5 in current phase
+Plan: 2 of 5 in current phase
 Status: In progress
-Last activity: 2026-01-13 - Completed 18-01-PLAN.md
+Last activity: 2026-01-13 - Completed 18-02-PLAN.md
 
 Progress: █████████░ 91%
 
@@ -128,6 +128,6 @@ Recent decisions affecting current work:
 ## Session Continuity
 
 Last session: 2026-01-13
-Stopped at: Completed 18-01-PLAN.md (File I/O route tests)
+Stopped at: Completed 18-02-PLAN.md (LLM route tests)
 Resume file: None
-Next action: Execute Plan 18-02 (run /gsd:execute-plan .planning/phases/18-api-route-tests/18-02-PLAN.md)
+Next action: Execute Plan 18-03 (run /gsd:execute-plan .planning/phases/18-api-route-tests/18-03-PLAN.md)

.planning/phases/18-api-route-tests/18-02-SUMMARY.md

@@ -0,0 +1,103 @@
+---
+phase: 18-api-route-tests
+plan: 02
+subsystem: testing
+tags: [vitest, api-routes, llm, google-genai, openai, mocking]
+
+# Dependency graph
+requires:
+  - phase: 18-01
+    provides: API route testing patterns with fs mocking
+provides:
+  - LLM route tests for Google and OpenAI providers
+  - @google/genai class mocking pattern with vi.hoisted
+  - fetch mocking for OpenAI API calls
+affects: [18-03, 18-04]
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns: [es6-class-mocking-with-hoisted, fetch-mocking-for-api]
+
+key-files:
+  created:
+    - src/app/api/llm/__tests__/route.test.ts
+  modified: []
+
+key-decisions:
+  - "Use vi.hoisted() for ES6 class mocks that need to work with 'new' keyword"
+  - "Mock global.fetch for external HTTP API calls (OpenAI)"
+
+patterns-established:
+  - "ES6 class mocking: vi.hoisted() to define mock class, return from vi.mock factory"
+  - "External API mocking: global.fetch with conditional responses per test"
+
+issues-created: []
+
+# Metrics
+duration: 4 min
+completed: 2026-01-13
+---
+
+# Phase 18 Plan 02: LLM Route Tests Summary
+
+**LLM API route tests for Google (18 tests) and OpenAI providers with ES6 class and fetch mocking**
+
+## Performance
+
+- **Duration:** 4 min
+- **Started:** 2026-01-13T14:51:00Z
+- **Completed:** 2026-01-13T14:55:00Z
+- **Tasks:** 2
+- **Files modified:** 1
+
+## Accomplishments
+- Created 18 tests for /api/llm route covering both providers
+- Established ES6 class mocking pattern using vi.hoisted() for GoogleGenAI
+- Established fetch mocking pattern for OpenAI API calls
+- Covered success, validation, rate limits, and API error paths
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Create LLM route tests for Google provider** - `6666b92` (test)
+2. **Task 2: Add LLM route tests for OpenAI provider** - `8ba3a71` (test)
+
+**Plan metadata:** (this commit)
+
+## Files Created/Modified
+- `src/app/api/llm/__tests__/route.test.ts` - 18 tests covering Google and OpenAI providers
+
+## Decisions Made
+- Used vi.hoisted() for ES6 class mocks to properly support instantiation with 'new'
+- Mock global.fetch for OpenAI API calls rather than mocking fetch library
+
+## Deviations from Plan
+
+### Auto-fixed Issues
+
+**1. [Rule 3 - Blocking] Fixed ES6 class mock pattern**
+- **Found during:** Task 1 (Google provider tests)
+- **Issue:** Initial mock using vi.fn() with factory function did not work with 'new' keyword
+- **Fix:** Used vi.hoisted() to define proper ES6 class mock for GoogleGenAI
+- **Files modified:** src/app/api/llm/__tests__/route.test.ts
+- **Verification:** Tests pass with hoisted class mock
+- **Committed in:** 6666b92
+
+---
+
+**Total deviations:** 1 auto-fixed (1 blocking), 0 deferred
+**Impact on plan:** Auto-fix necessary for class mocking to work. No scope creep.
+
+## Issues Encountered
+None - plan executed successfully.
+
+## Next Phase Readiness
+- ES6 class mocking pattern established for Gemini SDK
+- fetch mocking pattern ready for provider API calls
+- Ready for 18-03 (Generate route Gemini tests)
+
+---
+*Phase: 18-api-route-tests*
+*Completed: 2026-01-13*