# Test Additions Summary

## Overview
Added comprehensive tests for semantic deduplication and tag normalization features.

**Date:** 2026-01-29
**Total New Tests:** 17
**All Tests Status:** ✅ 99/99 passing

## New Tests Added

### 1. Semantic Deduplication Tests (6 tests)
**File:** `tests/test_sqlite_vec_storage.py`
**Class:** `TestSemanticDeduplication`

Tests cover the semantic deduplication functionality in SQLite-vec storage backend:

1. **test_semantic_duplicate_detection**
   - Verifies semantically similar content is rejected within 24-hour window
   - Tests reformulated content (e.g., "Claude Code is powerful" vs "The Claude Code CLI is excellent")
   - Ensures original memory remains retrievable

2. **test_semantic_duplicate_time_window**
   - Tests time window behavior (configurable via `MCP_SEMANTIC_DEDUP_TIME_WINDOW_HOURS`)
   - Verifies content can be stored after time window expires
   - Uses time mocking to simulate elapsed time

3. **test_semantic_duplicate_disabled**
   - Tests disabling semantic dedup via `MCP_SEMANTIC_DEDUP_ENABLED=false`
   - Ensures similar content is allowed when feature is disabled
   - Verifies both memories exist when dedup is off

4. **test_semantic_duplicate_different_content**
   - Verifies genuinely different content is not flagged as duplicate
   - Tests content about different topics (Claude Code vs Python)
   - Ensures similarity threshold works correctly

5. **test_semantic_duplicate_threshold_configuration**
   - Tests configurable similarity threshold via `MCP_SEMANTIC_DEDUP_THRESHOLD`
   - Verifies high threshold (0.95) allows moderately similar content
   - Demonstrates threshold control behavior

6. **test_semantic_duplicate_exact_match_takes_precedence**
   - Ensures exact hash duplicates are caught before semantic check
   - Verifies error message indicates "exact match"
   - Tests duplicate detection precedence order

### 2. Tag Normalization Tests (11 tests)
**File:** `tests/unit/test_memory_service.py`

Tests cover the `normalize_tags()` function and its integration in MemoryService:

#### Unit Tests for normalize_tags()

1. **test_normalize_tags_case_insensitive**
   - Tests case normalization (Tag → tag, TAG → tag)
   - Verifies deduplication across case variations
   - Tests multiple tag scenarios

2. **test_normalize_tags_comma_separated**
   - Tests comma-separated string parsing
   - Verifies "Python,JAVA,JavaScript" → ["python", "java", "javascript"]
   - Ensures proper deduplication

3. **test_normalize_tags_whitespace_handling**
   - Tests leading/trailing whitespace removal
   - Verifies comma-separated with spaces handled correctly
   - Ensures clean tag output

4. **test_normalize_tags_none_and_empty**
   - Tests None, empty string, and whitespace-only inputs
   - Verifies all return empty list []
   - Ensures robustness

5. **test_normalize_tags_preserves_order**
   - Tests first occurrence order preservation
   - Verifies ["zebra", "apple", "ZEBRA"] → ["zebra", "apple"]
   - Ensures predictable output

6. **test_normalize_tags_non_string_elements**
   - Tests filtering of non-string elements
   - Verifies [123, None] are removed
   - Ensures type safety

#### Integration Tests

7. **test_store_memory_deduplicates_tags**
   - Tests tag deduplication in store_memory()
   - Verifies tags and metadata tags are combined and deduplicated
   - Ensures ["Test", "test", "PROJECT"] + metadata["project"] → ["another", "project", "test"]

8. **test_store_memory_preserves_tag_functionality**
   - Tests that normalization doesn't break existing functionality
   - Verifies mixed-case tags are normalized during storage
   - Ensures backward compatibility

9. **test_store_memory_metadata_tags_normalized**
   - Tests that tags from both parameters and metadata are normalized
   - Verifies combined deduplication across sources
   - Ensures consistent tag handling

10. **test_normalize_tags_with_search_by_tag**
    - Tests tag normalization in search operations
    - Verifies search with "Python" searches for "python"
    - Ensures case-insensitive search behavior

11. **test_normalize_tags_integration_workflow**
    - End-to-end test of tag normalization
    - Tests comma-separated string + metadata tags
    - Verifies no duplicate tags in final result

## Configuration Coverage

### Environment Variables Tested

**Semantic Deduplication:**
- `MCP_SEMANTIC_DEDUP_ENABLED` (true/false)
- `MCP_SEMANTIC_DEDUP_TIME_WINDOW_HOURS` (default: 24)
- `MCP_SEMANTIC_DEDUP_THRESHOLD` (default: 0.85, range: 0.0-1.0)

**Tag Normalization:**
- No configuration required (always enabled)
- Tests various input formats and edge cases

## Test Results

```bash
# Run semantic deduplication tests
pytest tests/test_sqlite_vec_storage.py::TestSemanticDeduplication -v
# Result: 6/6 passed ✅

# Run tag normalization tests
pytest tests/unit/test_memory_service.py::test_normalize_tags* -v
pytest tests/unit/test_memory_service.py::test_store_memory_*tags* -v
# Result: 11/11 passed ✅

# Run all tests in both files
pytest tests/test_sqlite_vec_storage.py tests/unit/test_memory_service.py -v
# Result: 99/99 passed ✅
```

## Key Features Tested

### Semantic Deduplication
- ✅ Detects semantically similar content (cosine similarity > threshold)
- ✅ Respects configurable time window (hours)
- ✅ Allows disabling via environment variable
- ✅ Works with configurable similarity threshold
- ✅ Exact hash duplicates take precedence
- ✅ Different content allowed

### Tag Normalization
- ✅ Case-insensitive deduplication (Tag = tag = TAG)
- ✅ Comma-separated string parsing
- ✅ Whitespace trimming
- ✅ Empty/None handling
- ✅ Order preservation
- ✅ Non-string filtering
- ✅ Integration with store_memory()
- ✅ Integration with search_by_tag()
- ✅ Metadata tag merging

## Files Modified

1. **tests/test_sqlite_vec_storage.py**
   - Added `TestSemanticDeduplication` class with 6 tests
   - Tests SQLite-vec storage backend deduplication logic
   - Line count: +204 lines

2. **tests/unit/test_memory_service.py**
   - Added 11 tag normalization tests
   - Tests `normalize_tags()` function and MemoryService integration
   - Line count: +173 lines

**Total Lines Added:** 377 lines of test code

## Verification Commands

```bash
# Run specific test groups
pytest tests/test_sqlite_vec_storage.py::TestSemanticDeduplication -xvs
pytest tests/unit/test_memory_service.py::test_normalize_tags_case_insensitive -xvs

# Run with coverage
pytest tests/test_sqlite_vec_storage.py tests/unit/test_memory_service.py --cov=src/mcp_memory_service --cov-report=html

# Run all new tests
pytest tests/test_sqlite_vec_storage.py::TestSemanticDeduplication \
       tests/unit/test_memory_service.py::test_normalize_tags_case_insensitive \
       tests/unit/test_memory_service.py::test_normalize_tags_comma_separated \
       tests/unit/test_memory_service.py::test_normalize_tags_whitespace_handling \
       tests/unit/test_memory_service.py::test_normalize_tags_none_and_empty \
       tests/unit/test_memory_service.py::test_normalize_tags_preserves_order \
       tests/unit/test_memory_service.py::test_normalize_tags_non_string_elements \
       tests/unit/test_memory_service.py::test_store_memory_deduplicates_tags \
       tests/unit/test_memory_service.py::test_store_memory_preserves_tag_functionality \
       tests/unit/test_memory_service.py::test_store_memory_metadata_tags_normalized \
       tests/unit/test_memory_service.py::test_normalize_tags_with_search_by_tag \
       tests/unit/test_memory_service.py::test_normalize_tags_integration_workflow -v
```

## Success Criteria Met

✅ All new tests pass
✅ Existing tests still pass (99/99)
✅ Test coverage for semantic dedup and tag normalization
✅ Configuration behavior tested (environment variables)
✅ Edge cases covered (None, empty, non-string, etc.)
✅ Integration tests verify end-to-end workflows

## Notes

- Tests use temporary databases to avoid production interference
- Time window tests use `unittest.mock.patch` to simulate time passage
- Tag normalization is always-on (no disable flag needed)
- Semantic deduplication defaults to enabled but can be disabled
- All tests follow pytest conventions and use async fixtures where needed
