# Test Quality Audit Report

**Date**: 2026-01-05
**Auditor**: Claude Code (Opus 4.5)
**Methodology**: Deep analysis with focus on anti-pattern prevention, actual functionality testing, and regression prevention

---

## Executive Summary

**Total Test Files Audited**: 41
**Total Test Cases**: ~450+

### Score Distribution

| Score | Category | Count | Percentage |
|-------|----------|-------|------------|
| 5 | Essential | 8 | 19.5% |
| 4 | Valuable | 15 | 36.6% |
| 3 | Marginal | 11 | 26.8% |
| 2 | Weak | 5 | 12.2% |
| 1 | Delete | 2 | 4.9% |

### Key Findings

**Strengths**:
- SQLite database tests are exemplary - real database operations with proper setup/teardown
- Infrastructure tests (WMIC parsing, token calculator) use pure unit testing with no mocks
- Search strategy tests have comprehensive coverage of edge cases
- Logger formatTool tests are thorough and test actual transformation logic

**Critical Issues**:
- **context-builder.test.ts** has incomplete mocks that pollute the module cache, causing 81 test failures when run with the full suite
- Several tests verify mock behavior rather than actual functionality
- Type validation tests (export-types.test.ts) provide minimal value - TypeScript already validates types at compile time
- Some "validation" tests only verify code patterns exist, not that they work

**Recommendations**:
1. Fix or delete context-builder.test.ts - it actively harms the test suite
2. Delete trivial type validation tests that duplicate TypeScript compiler checks
3. Convert heavy-mock tests to integration tests where feasible
4. Add integration tests for critical paths (hook execution, worker API endpoints)

---

## Detailed Scores

### Score 5 - Essential (8 tests)

These tests catch real bugs, use minimal mocking, and test actual behavior.

| File | Test Count | Notes |
|------|------------|-------|
| `tests/sqlite/observations.test.ts` | 25+ | Real SQLite operations, in-memory DB, tests actual data persistence and retrieval |
| `tests/sqlite/sessions.test.ts` | 20+ | Real database CRUD operations, status transitions, relationship integrity |
| `tests/sqlite/transactions.test.ts` | 15+ | Critical transaction isolation tests, rollback behavior, error handling |
| `tests/context/token-calculator.test.ts` | 35+ | Pure unit tests, no mocks, tests actual token estimation algorithms |
| `tests/infrastructure/wmic-parsing.test.ts` | 20+ | Pure parsing logic tests, validates Windows process enumeration edge cases |
| `tests/utils/logger-format-tool.test.ts` | 56 | Comprehensive formatTool tests, validates JSON parsing, tool output formatting |
| `tests/server/server.test.ts` | 15+ | Real HTTP server integration tests, actual endpoint validation |
| `tests/cursor-hook-outputs.test.ts` | 12+ | Integration tests running actual hook scripts, validates real output |

**Why Essential**: These tests catch actual bugs before production. They test real behavior with minimal abstraction. The SQLite tests in particular are exemplary - they use an in-memory database but perform real SQL operations.

---

### Score 4 - Valuable (15 tests)

Good tests with acceptable mocking that still verify meaningful behavior.

| File | Test Count | Notes |
|------|------------|-------|
| `tests/sqlite/prompts.test.ts` | 15+ | Real DB operations for user prompts, timestamp handling |
| `tests/sqlite/summaries.test.ts` | 15+ | Real DB operations for session summaries |
| `tests/worker/search/search-orchestrator.test.ts` | 30+ | Comprehensive strategy selection logic, good edge case coverage |
| `tests/worker/search/strategies/sqlite-search-strategy.test.ts` | 25+ | Filter logic tests, date range handling |
| `tests/worker/search/strategies/hybrid-search-strategy.test.ts` | 20+ | Ranking preservation, merge logic |
| `tests/worker/search/strategies/chroma-search-strategy.test.ts` | 20+ | Vector search behavior, doc_type filtering |
| `tests/worker/search/result-formatter.test.ts` | 15+ | Output formatting validation |
| `tests/gemini_agent.test.ts` | 20+ | Multi-turn conversation flow, rate limiting fallback |
| `tests/infrastructure/health-monitor.test.ts` | 15+ | Health check logic, threshold validation |
| `tests/infrastructure/graceful-shutdown.test.ts` | 15+ | Shutdown sequence, timeout handling |
| `tests/infrastructure/process-manager.test.ts` | 12+ | Process lifecycle management |
| `tests/cursor-mcp-config.test.ts` | 10+ | MCP configuration generation validation |
| `tests/cursor-hooks-json-utils.test.ts` | 8+ | JSON parsing utilities |
| `tests/shared/settings-defaults-manager.test.ts` | 27 | Settings validation, migration logic |
| `tests/context/formatters/markdown-formatter.test.ts` | 15+ | Markdown generation, terminology consistency |

**Why Valuable**: These tests have some mocking but still verify important business logic. The search strategy tests are particularly good at testing the decision-making logic for query routing.

---

### Score 3 - Marginal (11 tests)

Tests with moderate value, often too much mocking or testing obvious behavior.

| File | Test Count | Issues |
|------|------------|--------|
| `tests/worker/agents/observation-broadcaster.test.ts` | 15+ | Heavy mocking of SSE workers, tests mock behavior more than actual broadcasting |
| `tests/worker/agents/fallback-error-handler.test.ts` | 10+ | Error message formatting tests, low complexity |
| `tests/worker/agents/session-cleanup-helper.test.ts` | 10+ | Cleanup logic with mocked dependencies |
| `tests/context/observation-compiler.test.ts` | 20+ | Mock database, tests query building not actual compilation |
| `tests/server/error-handler.test.ts` | 8+ | Mock Express response, tests formatting only |
| `tests/cursor-registry.test.ts` | 8+ | Registry pattern tests, low risk area |
| `tests/cursor-context-update.test.ts` | 5+ | File format validation, could be stricter |
| `tests/hook-constants.test.ts` | 5+ | Constant validation, low value |
| `tests/session_store.test.ts` | 10+ | In-memory store tests, straightforward logic |
| `tests/logger-coverage.test.ts` | 8+ | Coverage verification, not functionality |
| `tests/scripts/smart-install.test.ts` | 25+ | Path array tests, replicates rather than imports logic |

**Why Marginal**: These tests provide some regression protection but either mock too heavily or test low-risk areas. The smart-install tests notably replicate the path arrays from the source file rather than testing the actual module.

---

### Score 2 - Weak (5 tests)

Tests that mostly verify mocks work or provide little value.

| File | Test Count | Issues |
|------|------------|--------|
| `tests/worker/agents/response-processor.test.ts` | 20+ | **Heavy mocking**: >50% setup is mock configuration. Tests verify mocks are called, not that XML parsing actually works |
| `tests/session_id_refactor.test.ts` | 10+ | **Code pattern validation**: Tests that certain patterns exist in code, not that they work |
| `tests/session_id_usage_validation.test.ts` | 5+ | **Static analysis as tests**: Reads files and checks for string patterns. Should be a lint rule, not a test |
| `tests/validate_sql_update.test.ts` | 5+ | **One-time validation**: Validated a migration, no ongoing value |
| `tests/worker-spawn.test.ts` | 5+ | **Trivial mocking**: Tests spawn config exists, doesn't test actual spawning |

**Why Weak**: These tests create false confidence. The response-processor tests in particular set up elaborate mocks and then verify those mocks were called - they don't verify actual XML parsing or database operations work correctly.

---

### Score 1 - Delete (2 tests)

Tests that actively harm the codebase or provide zero value.

| File | Test Count | Issues |
|------|------------|--------|
| `tests/context/context-builder.test.ts` | 20+ | **CRITICAL**: Incomplete logger mock pollutes module cache. Causes 81 test failures when run with full suite. Tests verify mocks, not actual context building |
| `tests/scripts/export-types.test.ts` | 30+ | **Zero runtime value**: Tests TypeScript type definitions compile. TypeScript compiler already does this. These tests can literally never fail at runtime |

**Why Delete**:
- **context-builder.test.ts**: This test is actively harmful. It imports the logger module with an incomplete mock (only 4 of 13+ methods mocked), and this polluted mock persists in Bun's module cache. When other tests run afterwards, they get the broken logger singleton. The test itself only verifies that mocked methods were called with expected arguments - it doesn't test actual context building logic.
- **export-types.test.ts**: These tests instantiate TypeScript interfaces and verify properties exist. TypeScript already validates this at compile time. If a type definition is wrong, the code won't compile. These runtime tests add overhead without catching any bugs that TypeScript wouldn't already catch.

---

## Missing Test Coverage

### Critical Gaps

| Area | Risk | Current Coverage | Recommendation |
|------|------|------------------|----------------|
| **Hook execution E2E** | HIGH | None | Add integration tests that run hooks with real Claude Code SDK |
| **Worker API endpoints** | HIGH | Partial (server.test.ts) | Add tests for all REST endpoints: `/observe`, `/search`, `/health` |
| **Chroma vector sync** | HIGH | None | Add tests for ChromaSync.ts embedding generation and retrieval |
| **Database migrations** | MEDIUM | None | Add tests for schema migrations, especially version upgrades |
| **Settings file I/O** | MEDIUM | Partial | Add tests for settings file creation, corruption recovery |
| **Tag stripping** | MEDIUM | None | Add tests for `<private>` and `<meta-observation>` tag handling |
| **MCP tool handlers** | MEDIUM | None | Add tests for search, timeline, get_observations MCP tools |
| **Error recovery** | MEDIUM | Minimal | Add tests for worker crash recovery, database corruption handling |

### Recommended New Tests

1. **`tests/integration/hook-execution.test.ts`**
   - Run actual hooks with mocked Claude Code environment
   - Verify data flows correctly through SessionStart -> PostToolUse -> SessionEnd

2. **`tests/integration/worker-api.test.ts`**
   - Start actual worker server
   - Make real HTTP requests to all endpoints
   - Verify response formats and error handling

3. **`tests/services/chroma-sync.test.ts`**
   - Test embedding generation with real text
   - Test semantic similarity retrieval
   - Test sync between SQLite and Chroma

4. **`tests/utils/tag-stripping.test.ts`**
   - Test `<private>` tag removal
   - Test `<meta-observation>` tag handling
   - Test nested tag scenarios

---

## Recommendations

### Immediate Actions

1. **Delete or fix `tests/context/context-builder.test.ts`** (Priority: CRITICAL)
   - This test causes 81 other tests to fail due to module cache pollution
   - Either complete the logger mock (all 13+ methods) or delete entirely
   - Recommended: Delete and rewrite as integration test without mocks

2. **Delete `tests/scripts/export-types.test.ts`** (Priority: HIGH)
   - Zero runtime value - TypeScript compiler already validates types
   - Remove to reduce test suite noise

3. **Delete or convert validation tests** (Priority: MEDIUM)
   - `tests/session_id_refactor.test.ts` - Was useful during migration, no longer needed
   - `tests/session_id_usage_validation.test.ts` - Convert to lint rule
   - `tests/validate_sql_update.test.ts` - Was useful during migration, no longer needed

### Architecture Improvements

1. **Create test utilities for common mocks**
   - Centralize logger mock in `tests/utils/mock-logger.ts` with ALL methods
   - Centralize database mock with proper transaction support
   - Prevent incomplete mocks from polluting module cache

2. **Add integration test suite**
   - Create `tests/integration/` directory
   - Run with real worker server (separate database)
   - Test actual data flow, not mock interactions

3. **Implement test isolation**
   - Use `beforeEach` to reset module state
   - Consider test file ordering to prevent cache pollution
   - Add cleanup hooks for database state

### Quality Guidelines

For future tests, follow these principles:

1. **Prefer real implementations over mocks**
   - Use in-memory SQLite instead of mock database
   - Use real HTTP requests instead of mock req/res
   - Mock only external services (AI APIs, file system when needed)

2. **Test behavior, not implementation**
   - Bad: "verify function X was called with argument Y"
   - Good: "verify output contains expected data after operation"

3. **Each test should be able to fail**
   - If a test cannot fail (like type validation tests), it's not testing anything
   - Write tests that would catch real bugs

4. **Keep test setup minimal**
   - If >50% of test is mock setup, consider integration testing
   - Complex mock setup often indicates testing the wrong thing

---

## Appendix: Full Test File Inventory

| File | Score | Tests | LOC | Mock % |
|------|-------|-------|-----|--------|
| `tests/context/context-builder.test.ts` | 1 | 20+ | 400+ | 80% |
| `tests/context/formatters/markdown-formatter.test.ts` | 4 | 15+ | 200+ | 10% |
| `tests/context/observation-compiler.test.ts` | 3 | 20+ | 300+ | 60% |
| `tests/context/token-calculator.test.ts` | 5 | 35+ | 400+ | 0% |
| `tests/cursor-context-update.test.ts` | 3 | 5+ | 100+ | 20% |
| `tests/cursor-hook-outputs.test.ts` | 5 | 12+ | 250+ | 10% |
| `tests/cursor-hooks-json-utils.test.ts` | 4 | 8+ | 150+ | 0% |
| `tests/cursor-mcp-config.test.ts` | 4 | 10+ | 200+ | 20% |
| `tests/cursor-registry.test.ts` | 3 | 8+ | 150+ | 30% |
| `tests/gemini_agent.test.ts` | 4 | 20+ | 400+ | 40% |
| `tests/hook-constants.test.ts` | 3 | 5+ | 80+ | 0% |
| `tests/infrastructure/graceful-shutdown.test.ts` | 4 | 15+ | 300+ | 40% |
| `tests/infrastructure/health-monitor.test.ts` | 4 | 15+ | 250+ | 30% |
| `tests/infrastructure/process-manager.test.ts` | 4 | 12+ | 200+ | 35% |
| `tests/infrastructure/wmic-parsing.test.ts` | 5 | 20+ | 240+ | 0% |
| `tests/logger-coverage.test.ts` | 3 | 8+ | 150+ | 20% |
| `tests/scripts/export-types.test.ts` | 1 | 30+ | 350+ | 0% |
| `tests/scripts/smart-install.test.ts` | 3 | 25+ | 230+ | 0% |
| `tests/server/error-handler.test.ts` | 3 | 8+ | 150+ | 50% |
| `tests/server/server.test.ts` | 5 | 15+ | 300+ | 20% |
| `tests/session_id_refactor.test.ts` | 2 | 10+ | 200+ | N/A |
| `tests/session_id_usage_validation.test.ts` | 2 | 5+ | 150+ | N/A |
| `tests/session_store.test.ts` | 3 | 10+ | 180+ | 10% |
| `tests/shared/settings-defaults-manager.test.ts` | 4 | 27 | 400+ | 20% |
| `tests/sqlite/observations.test.ts` | 5 | 25+ | 400+ | 0% |
| `tests/sqlite/prompts.test.ts` | 4 | 15+ | 250+ | 0% |
| `tests/sqlite/sessions.test.ts` | 5 | 20+ | 350+ | 0% |
| `tests/sqlite/summaries.test.ts` | 4 | 15+ | 250+ | 0% |
| `tests/sqlite/transactions.test.ts` | 5 | 15+ | 300+ | 0% |
| `tests/utils/logger-format-tool.test.ts` | 5 | 56 | 1000+ | 0% |
| `tests/validate_sql_update.test.ts` | 2 | 5+ | 100+ | N/A |
| `tests/worker/agents/fallback-error-handler.test.ts` | 3 | 10+ | 200+ | 40% |
| `tests/worker/agents/observation-broadcaster.test.ts` | 3 | 15+ | 350+ | 60% |
| `tests/worker/agents/response-processor.test.ts` | 2 | 20+ | 500+ | 70% |
| `tests/worker/agents/session-cleanup-helper.test.ts` | 3 | 10+ | 200+ | 50% |
| `tests/worker/search/result-formatter.test.ts` | 4 | 15+ | 250+ | 20% |
| `tests/worker/search/search-orchestrator.test.ts` | 4 | 30+ | 500+ | 45% |
| `tests/worker/search/strategies/chroma-search-strategy.test.ts` | 4 | 20+ | 350+ | 50% |
| `tests/worker/search/strategies/hybrid-search-strategy.test.ts` | 4 | 20+ | 300+ | 45% |
| `tests/worker/search/strategies/sqlite-search-strategy.test.ts` | 4 | 25+ | 350+ | 40% |
| `tests/worker-spawn.test.ts` | 2 | 5+ | 100+ | 60% |

---

*Report generated by Claude Code (Opus 4.5) on 2026-01-05*
