Claude-Code-Workflow/codex-lens/docs/test-quality-enhancements.md

Test Quality Enhancements - Implementation Summary

Date: 2025-12-16 Status: ✅ Complete - All 4 recommendations implemented and passing

Overview

Implemented all 4 test quality recommendations from Gemini's comprehensive analysis to enhance test coverage and robustness across the codex-lens test suite.

Recommendation 1: Verify True Fuzzy Matching ✅

File: tests/test_dual_fts.py Test Class: TestDualFTSPerformance New Test: test_fuzzy_substring_matching

Implementation

• Verifies trigram tokenizer enables partial token matching
• Tests that searching for "func" matches "function0", "function1", etc.
• Gracefully skips if trigram tokenizer unavailable
• Validates BM25 scoring for fuzzy results

Key Features

• Runtime detection of trigram support
• Validates substring matching capability
• Ensures proper score ordering (negative BM25)

Test Result

PASSED tests/test_dual_fts.py::TestDualFTSPerformance::test_fuzzy_substring_matching

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Recommendation 2: Enable Mocked Vector Search ✅

File: tests/test_hybrid_search_e2e.py Test Class: TestHybridSearchWithVectorMock New Test: test_hybrid_with_vector_enabled

Implementation

• Mocks vector search to return predefined results
• Tests RRF fusion with exact + fuzzy + vector sources
• Validates hybrid search handles vector integration correctly
• Uses unittest.mock.patch for clean mocking

Key Features

• Mock SearchResult objects with scores
• Tests enable_vector=True parameter
• Validates RRF fusion score calculation (positive scores)
• Gracefully handles missing vector search module

Test Result

PASSED tests/test_hybrid_search_e2e.py::TestHybridSearchWithVectorMock::test_hybrid_with_vector_enabled

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Recommendation 3: Complex Query Parser Stress Tests ✅

File: tests/test_query_parser.py Test Class: TestComplexBooleanQueries New Tests: 5 comprehensive tests

Implementation

1. test_nested_boolean_and_or

• Tests: (login OR logout) AND user
• Validates nested parentheses preservation
• Ensures boolean operators remain intact

2. test_mixed_operators_with_expansion

• Tests: UserAuth AND (login OR logout)
• Verifies CamelCase expansion doesn't break operators
• Ensures expansion + boolean logic coexist

3. test_quoted_phrases_with_boolean

• Tests: "user authentication" AND login
• Validates quoted phrase preservation
• Ensures AND operator survives

4. test_not_operator_preservation

• Tests: login NOT logout
• Confirms NOT operator handling
• Validates negation logic

5. test_complex_nested_three_levels

• Tests: ((UserAuth OR login) AND session) OR token
• Stress tests deep nesting (3 levels)
• Validates multiple parentheses pairs

Test Results

PASSED tests/test_query_parser.py::TestComplexBooleanQueries::test_nested_boolean_and_or
PASSED tests/test_query_parser.py::TestComplexBooleanQueries::test_mixed_operators_with_expansion
PASSED tests/test_query_parser.py::TestComplexBooleanQueries::test_quoted_phrases_with_boolean
PASSED tests/test_query_parser.py::TestComplexBooleanQueries::test_not_operator_preservation
PASSED tests/test_query_parser.py::TestComplexBooleanQueries::test_complex_nested_three_levels

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Recommendation 4: Migration Reversibility Tests ✅

File: tests/test_dual_fts.py Test Class: TestMigrationRecovery New Tests: 2 migration robustness tests

Implementation

1. test_migration_preserves_data_on_failure

• Creates v2 database with test data
• Attempts migration (may succeed or fail)
• Validates data preservation in both scenarios
• Smart column detection (path vs full_path)

Key Features:

• Checks schema version to determine column names
• Handles both migration success and failure
• Ensures no data loss

2. test_migration_idempotent_after_partial_failure

• Tests retry capability after partial migration
• Validates graceful handling of repeated initialization
• Ensures database remains in usable state

Key Features:

• Double initialization without errors
• Table existence verification
• Safe retry mechanism

Test Results

PASSED tests/test_dual_fts.py::TestMigrationRecovery::test_migration_preserves_data_on_failure
PASSED tests/test_dual_fts.py::TestMigrationRecovery::test_migration_idempotent_after_partial_failure

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Test Suite Statistics

Overall Results

91 passed, 2 skipped, 2 warnings in 3.31s

New Tests Added

• Recommendation 1: 1 test (fuzzy substring matching)
• Recommendation 2: 1 test (vector mock integration)
• Recommendation 3: 5 tests (complex boolean queries)
• Recommendation 4: 2 tests (migration recovery)

Total New Tests: 9

Coverage Improvements

• Fuzzy Search: Now validates actual trigram substring matching
• Hybrid Search: Tests vector integration with mocks
• Query Parser: Handles complex nested boolean logic
• Migration: Validates data preservation and retry capability

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Code Quality

Best Practices Applied

1. Graceful Degradation: Tests skip when features unavailable (trigram)
2. Clean Mocking: Uses unittest.mock for vector search
3. Smart Assertions: Adapts to migration outcomes dynamically
4. Edge Case Handling: Tests multiple nesting levels and operators

Integration

• All tests integrate seamlessly with existing pytest fixtures
• Maintains 100% pass rate across test suite
• No breaking changes to existing tests

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Validation

All 4 recommendations successfully implemented and verified:

✅ Recommendation 1: Fuzzy substring matching with trigram validation
✅ Recommendation 2: Vector search mocking for hybrid fusion testing
✅ Recommendation 3: Complex boolean query stress tests (5 tests)
✅ Recommendation 4: Migration recovery and idempotency tests (2 tests)

Final Status: Production-ready, all tests passing