noteflow/.sisyphus/notepads/client-optimizations/learnings.md

Client Optimizations - Learnings

Task 4: E2E Dedup Verification Tests

Completed

• Created client/src/api/adapters/tauri/__tests__/dedup.test.ts with 9 comprehensive E2E tests
• Created client/src/api/adapters/tauri/__tests__/constants.ts for test constants (no magic numbers)
• All tests pass: 9/9 ✓

Test Coverage

1. Concurrent dedup to same command - 3 concurrent calls → invoke called once → all get same result
2. Different arguments - 2 calls with different args → invoke called twice (no dedup)
3. Identical arguments - 2 calls with same args → invoke called once (dedup)
4. Complex arguments - 5 concurrent calls with complex args → invoke called once
5. Promise sharing - Verifies all concurrent callers resolve at same time (timing check)
6. Error handling - All concurrent callers receive same error instance
7. Concurrent within window - Concurrent requests within dedup window are deduplicated
8. Window expiration - Requests after window expires are NOT deduplicated (new call)
9. Undefined arguments - 3 concurrent calls with no args → invoke called once

Key Insights

• Dedup implementation removes entry from map after promise settles (not TTL-based for settled promises)
• Sequential calls after settlement are NOT deduplicated (by design)
• Only concurrent/in-flight requests share promises
• Test constants extracted to prevent magic number violations
• All 207 API tests pass (26 test files)

Test Patterns Used

• createMocks() from test-utils for invoke/listen mocks
• mockImplementation() for simulating network delays
• Promise.all() for concurrent request testing
• Timing assertions for promise sharing verification
• Error propagation testing with .catch()

Task 5: Optimistic Mutation Hook

Completed

• Created client/src/hooks/data/use-optimistic-mutation.ts with full generic support
• Created client/src/hooks/data/use-optimistic-mutation.test.tsx with 13 comprehensive tests
• All tests pass: 13/13 ✓
• All data hooks tests pass: 26/26 ✓

Hook Signature

interface UseOptimisticMutationOptions<TData, TVariables, TContext> {
  mutationFn: (variables: TVariables) => Promise<TData>;
  onMutate?: (variables: TVariables) => TContext | Promise<TContext>;
  onSuccess?: (data: TData, variables: TVariables, context?: TContext) => void;
  onError?: (error: Error, variables: TVariables, context?: TContext) => void;
}

interface UseOptimisticMutationResult<TVariables> {
  mutate: (variables: TVariables) => Promise<void>;
  isLoading: boolean;
  error: Error | null;
}

Test Coverage

1. onMutate called before mutation - Verifies optimistic update timing
2. onSuccess with context - Context properly passed through lifecycle
3. onSuccess without context - Works when onMutate not provided
4. onError with context - Context available for rollback
5. onError without context - Handles missing onMutate gracefully
6. Toast on error - Automatic error notification
7. isLoading state - Proper loading state management
8. Error state - Error captured and cleared on success
9. Async onMutate - Handles async context preparation
10. Unmount cleanup - Prevents state updates after unmount
11. Sequential mutations - Multiple mutations work correctly
12. Variables passed correctly - Arguments flow through properly
13. Multiple sequential mutations - Handles repeated calls

Key Implementation Details

• Generic types: TData, TVariables, TContext (optional, defaults to undefined)
• Context stored during onMutate, passed to onSuccess/onError for rollback
• Toast integration for automatic error notifications
• Mounted ref prevents state updates after unmount
• Async onMutate support for complex optimistic updates
• Error state cleared on successful mutation

Test Patterns Used

• renderHook() for hook testing
• act() for state updates
• waitFor() for async assertions
• Mock functions with vi.fn() for callbacks
• Toast mock with proper return type
• Async/await for mutation testing

Integration Points

• Uses useToast() from @/hooks/ui/use-toast
• Follows existing mutation patterns from use-async-data.ts
• Compatible with React 18+ hooks
• No external dependencies beyond React

Learnings

• TDD approach (RED → GREEN → REFACTOR) works well for hooks
• Generic type parameters need careful handling in TypeScript
• Mounted ref cleanup is essential for preventing memory leaks
• Toast integration should be automatic for error cases
• Context pattern enables proper optimistic update + rollback flow

Task 6: Meeting Mutations Hooks

Completed

• Created client/src/hooks/meetings/use-meeting-mutations.ts with useCreateMeeting() and useDeleteMeeting() hooks
• Created client/src/hooks/meetings/use-meeting-mutations.test.tsx with 16 comprehensive tests
• All tests pass: 16/16 ✓
• Type-check passes: 0 errors
• Lint passes: 0 errors

Hook Implementations

useCreateMeeting

export function useCreateMeeting() {
  return {
    mutate: (variables: CreateMeetingRequest) => Promise<void>;
    isLoading: boolean;
    error: Error | null;
  };
}

Optimistic Update Flow:

1. onMutate: Create temp meeting with temp-${Date.now()} ID, cache it immediately
2. onSuccess: Remove temp meeting, cache real meeting from server
3. onError: Remove temp meeting (rollback)

useDeleteMeeting

export function useDeleteMeeting() {
  return {
    mutate: (meetingId: string) => Promise<void>;
    isLoading: boolean;
    error: Error | null;
  };
}

Optimistic Update Flow:

1. onMutate: Get meeting from cache, remove it immediately, return snapshot for rollback
2. onSuccess: No-op (meeting already removed)
3. onError: Restore meeting from context snapshot

Test Coverage (16 tests)

useCreateMeeting (8 tests):

1. Optimistic meeting appears immediately (before API resolves)
2. Success replaces optimistic with real meeting
3. Error removes optimistic meeting and shows toast
4. Handles metadata and project_id correctly
5. Handles project_ids array
6. Exposes loading state
7. Exposes error state
8. Clears error on successful mutation

useDeleteMeeting (8 tests):

1. Optimistic removal (meeting disappears immediately)
2. Success keeps meeting removed
3. Error restores meeting from context
4. Handles missing meeting gracefully
5. Handles API returning false (not found)
6. Exposes loading state
7. Exposes error state
8. Clears error on successful mutation

Key Implementation Details

• Both hooks use useOptimisticMutation from Task 5
• Meeting cache integration for immediate UI feedback
• Context pattern for rollback on errors
• Proper error handling with automatic toast notifications
• Loading state management for UI feedback
• Type-safe with no any types

Test Patterns Used

• renderHook() for hook testing
• act() for wrapping state updates
• waitFor() for async assertions
• vi.mocked() for type-safe mock assertions
• Mock API with mockResolvedValue() and mockRejectedValue()
• Proper cleanup with beforeEach(vi.clearAllMocks())

Integration Points

• Uses useOptimisticMutation from @/hooks/data/use-optimistic-mutation
• Uses meetingCache from @/lib/cache/meeting-cache
• Uses getAPI() from @/api/interface
• Follows existing hook patterns from codebase

Learnings

• TDD approach (tests first) ensures comprehensive coverage
• Optimistic updates require careful context management for rollback
• act() wrapper is essential for state update assertions
• Meeting cache provides immediate UI feedback without server round-trip
• Context pattern enables clean separation of concerns (optimistic vs rollback)
• Type-safe mocking with vi.mocked() prevents test bugs
• Empty onSuccess callback is valid when no post-success logic needed

Task 7: Annotation & Project Mutation Hooks

Completed

• Created client/src/hooks/annotations/use-annotation-mutations.ts with useAddAnnotation() and useDeleteAnnotation() hooks
• Created client/src/hooks/annotations/use-annotation-mutations.test.tsx with 12 comprehensive tests
• Created client/src/hooks/projects/use-project-mutations.ts with useCreateProject() and useDeleteProject() hooks
• Created client/src/hooks/projects/use-project-mutations.test.tsx with 12 comprehensive tests
• All tests pass: 24/24 ✓
• Type-check passes: 0 errors
• Lint passes: 0 errors
• All hooks tests pass: 379/379 ✓ (no regressions)

Hook Implementations

useAddAnnotation

export function useAddAnnotation() {
  return {
    mutate: (variables: AddAnnotationRequest) => Promise<void>;
    isLoading: boolean;
    error: Error | null;
  };
}

Design:

• No optimistic updates (annotations are per-meeting, fetched on demand)
• No cache (parent components refetch after mutation)
• onMutate: Returns undefined (no context needed)
• onSuccess: No-op (parent handles refetch)
• onError: No-op (toast auto-shown by useOptimisticMutation)

useDeleteAnnotation

export function useDeleteAnnotation() {
  return {
    mutate: (annotationId: string) => Promise<void>;
    isLoading: boolean;
    error: Error | null;
  };
}

Design:

• No optimistic updates (parent refetches)
• No cache
• onMutate: Returns undefined
• onSuccess: No-op
• onError: No-op (toast auto-shown)

useCreateProject

export function useCreateProject() {
  return {
    mutate: (variables: CreateProjectRequest) => Promise<void>;
    isLoading: boolean;
    error: Error | null;
  };
}

Design:

• No optimistic updates (projects are workspace-level, fetched on demand)
• No cache (parent components refetch)
• onMutate: Returns undefined
• onSuccess: No-op
• onError: No-op (toast auto-shown)

useDeleteProject

export function useDeleteProject() {
  return {
    mutate: (projectId: string) => Promise<void>;
    isLoading: boolean;
    error: Error | null;
  };
}

Design:

• No optimistic updates (parent refetches)
• No cache
• onMutate: Returns undefined
• onSuccess: No-op
• onError: No-op (toast auto-shown)

Test Coverage (24 tests)

useAddAnnotation (6 tests):

1. Calls API with correct request
2. Returns annotation on success
3. Exposes loading state
4. Exposes error state
5. Clears error on successful mutation
6. Handles segment_ids correctly

useDeleteAnnotation (6 tests):

1. Calls API with annotation ID
2. Returns true on success
3. Exposes loading state
4. Exposes error state
5. Handles API returning false (not found)
6. Clears error on successful mutation

useCreateProject (6 tests):

1. Calls API with correct request
2. Returns project on success
3. Exposes loading state
4. Exposes error state
5. Clears error on successful mutation
6. Handles workspace_id correctly

useDeleteProject (6 tests):

1. Calls API with project ID
2. Returns true on success
3. Exposes loading state
4. Exposes error state
5. Handles API returning false (not found)
6. Clears error on successful mutation

Key Implementation Details

• All hooks use useOptimisticMutation from Task 5
• No client-side caching (parent components handle refetch)
• No optimistic updates (simpler pattern for non-cached entities)
• Context type is undefined (no rollback needed)
• Proper error handling with automatic toast notifications
• Loading state management for UI feedback
• Type-safe with no any types

Test Patterns Used

• renderHook() for hook testing
• act() for wrapping state updates
• waitFor() for async assertions
• Mock API with mockResolvedValue() and mockRejectedValue()
• Proper cleanup with beforeEach(vi.clearAllMocks())

Integration Points

• Uses useOptimisticMutation from @/hooks/data/use-optimistic-mutation
• Uses getAPI() from @/api/interface
• Follows existing hook patterns from Task 6 (meeting mutations)

Learnings

• TDD approach (tests first) ensures comprehensive coverage
• Simpler pattern for non-cached entities (no optimistic updates)
• Context pattern is flexible: can be undefined when no rollback needed
• Parent components responsible for refetch after mutation
• Toast integration automatic via useOptimisticMutation
• Type-safe mocking prevents test bugs
• All hooks follow consistent pattern for maintainability

Differences from Task 6 (Meeting Mutations)

• No cache: Annotations and projects don't have client-side caches
• No optimistic updates: Parent components refetch after mutations
• Simpler context: undefined instead of snapshot objects
• Same pattern: Still use useOptimisticMutation for consistency
• Same error handling: Toast auto-shown by useOptimisticMutation

Quality Gates Passed

1. ✓ All 24 tests pass
2. ✓ Type-check: 0 errors
3. ✓ Lint: 0 errors
4. ✓ All hooks tests: 379/379 pass (no regressions)

Task 8: Analytics Cache Invalidation on Meeting Completion

Completed

• Created tests/grpc/test_post_processing_analytics.py with 3 comprehensive tests
• Modified src/noteflow/grpc/mixins/meeting/_post_processing.py to invalidate analytics cache
• Added analytics_service field to ServicerState protocol
• All tests pass: 3/3 ✓
• Type-check passes: 0 errors
• Lint passes: 0 errors

Implementation Details

Changes Made

1. Test File: tests/grpc/test_post_processing_analytics.py

   • test_complete_meeting_invalidates_analytics_cache: Verifies cache invalidation is called
   • test_complete_meeting_with_none_analytics_service: Handles None analytics_service gracefully
   • test_complete_meeting_passes_correct_workspace_id: Verifies correct workspace_id is passed

2. Post-Processing Module: src/noteflow/grpc/mixins/meeting/_post_processing.py

   • Modified _complete_meeting() to accept analytics_service and workspace_id parameters
   • Added logic to call analytics_service.invalidate_cache(workspace_id) when meeting completes
   • Added logging: logger.info("Invalidated analytics cache", workspace_id=...)
   • Updated _SummaryCompletionContext dataclass to include analytics_service field
   • Updated _complete_without_summary() to accept and pass analytics_service
   • Updated _save_summary_and_complete() to use analytics_service from context
   • Updated call sites in _process_summary() to pass analytics_service

3. ServicerState Protocol: src/noteflow/grpc/mixins/_servicer_state.py

   • Added AnalyticsService import to TYPE_CHECKING block
   • Added analytics_service: AnalyticsService | None field to protocol

Key Design Decisions

• Workspace ID Retrieval: Used get_workspace_id() from context variables instead of passing through all layers
  • Rationale: Context variables are set by gRPC interceptor and available throughout request lifecycle
  • Fallback: If context variable not set, use explicitly passed workspace_id parameter
• Optional Analytics Service: Made analytics_service optional (None-safe)
  • Rationale: Post-processing can run without analytics service (feature may be disabled)
• Logging: Added structured logging with workspace_id for observability
  • Rationale: Helps track cache invalidation events in production

Test Coverage

1. Cache Invalidation Called: Verifies invalidate_cache() is called when meeting completes
2. Graceful Handling: Verifies function works when analytics_service is None
3. Correct Workspace ID: Verifies correct workspace_id is passed to invalidate_cache

Type Safety

• No Any types used
• No # type: ignore comments (except for private function import in tests, which is standard)
• Full type coverage with proper Protocol definitions

Quality Gates Passed

1. ✓ All 3 tests pass
2. ✓ Type-check: 0 errors, 0 warnings, 0 notes
3. ✓ Lint: 0 errors
4. ✓ Cache invalidation called with correct workspace_id
5. ✓ Invalidation event logged

Learnings

• TDD approach (tests first) ensures comprehensive coverage
• Context variables are the right way to access request-scoped data in async code
• Optional parameters with None-safe checks are better than required parameters
• Structured logging with context (workspace_id) improves observability
• Protocol definitions in ServicerState need to match actual implementation in service.py

Task 9: Analytics Cache Invalidation Integration Tests

Implementation Summary

Created comprehensive integration tests for analytics cache invalidation flow in tests/application/services/analytics/test_cache_invalidation.py.

Key Findings

1. Test Pattern: Behavior Verification Over State Inspection

• Pattern: Verify cache behavior through DB call counts, not by inspecting protected _overview_cache attributes
• Why: Protected attributes (_*) trigger type checker warnings when accessed outside the class
• Solution: Use mock call counts to verify cache hits/misses indirectly
  • Cache hit: DB call count stays same after second query
  • Cache miss: DB call count increments after invalidation

2. Test Constants for Magic Numbers

• Requirement: All numeric literals must be defined as Final constants
• Applied to:
  • Expected counts (meetings, segments, speakers)
  • Cache sizes (empty=0, single=1, two=2)
  • DB call expectations (first=1, after_hit=1, after_invalidation=2)
  • Speaker stats (time, segments, meetings, confidence)
• Benefit: Self-documenting test code, easier to adjust expectations

3. Integration Test Structure

• Setup: Create mock UoW with async context managers
• Act: Execute queries and invalidation operations
• Assert: Verify DB call counts reflect cache behavior
• Pattern: Matches existing analytics service tests in test_analytics_service.py

4. Logging Verification

• Cache invalidation logs analytics_cache_invalidated message
• Cache misses log analytics_cache_miss with metadata (cache_type, workspace_id, counts)
• Cache hits log analytics_cache_hit with metadata
• Clearing all caches logs analytics_cache_cleared_all

5. Multi-Workspace Cache Isolation

• Each workspace has independent cache entries
• Invalidating one workspace doesn't affect others
• Invalidating with None clears all workspaces
• Verified through DB call count patterns

Test Coverage

• test_meeting_completion_invalidates_cache_integration: Full flow (query → cache → invalidate → query)
• test_invalidate_cache_clears_all_cache_types: Multiple cache types (overview + speaker stats)
• test_invalidate_cache_with_none_clears_all_workspaces: Global invalidation
• test_invalidate_cache_preserves_other_workspaces: Workspace isolation

Quality Metrics

• ✅ All 4 tests pass
• ✅ Type check: 0 errors, 0 warnings, 0 notes
• ✅ Lint check: All checks passed
• ✅ No protected attribute access violations
• ✅ All magic numbers defined as constants

Lessons for Future Tests

1. Use DB call counts to verify cache behavior indirectly
2. Define all numeric literals as Final constants upfront
3. Follow existing test patterns in the codebase (e.g., test_analytics_service.py)
4. Test cache isolation across workspaces explicitly
5. Verify logging output through log messages, not internal state