czlonkowski--n8n-mcp/tests/unit/database/README.md

Database Layer Unit Tests

This directory contains comprehensive unit tests for the database layer components of n8n-mcp.

Test Coverage

node-repository.ts - 100% Coverage ✅

• saveNode method with JSON serialization
• getNode method with JSON deserialization
• getAITools method
• safeJsonParse private method
• Edge cases: large JSON, boolean conversion, invalid JSON handling

template-repository.ts - 80.31% Coverage ✅

• FTS5 initialization and fallback
• saveTemplate with sanitization
• getTemplate and getTemplatesByNodes
• searchTemplates with FTS5 and LIKE fallback
• getTemplatesForTask with task mapping
• Template statistics and maintenance operations
• Uncovered: Some error paths in FTS5 operations

database-adapter.ts - Tested via Mocks

• Interface compliance tests
• PreparedStatement implementation
• Transaction support
• FTS5 detection logic
• Error handling patterns

Test Strategy

The tests use a mock-based approach to:

1. Isolate database operations from actual database dependencies
2. Test business logic without requiring real SQLite/sql.js
3. Ensure consistent test execution across environments
4. Focus on behavior rather than implementation details

Key Test Files

• node-repository-core.test.ts - Core NodeRepository functionality
• template-repository-core.test.ts - Core TemplateRepository functionality
• database-adapter-unit.test.ts - DatabaseAdapter interface and patterns

Running Tests

# Run all database tests
npm test -- tests/unit/database/

# Run with coverage
npm run test:coverage -- tests/unit/database/

# Run specific test file
npm test -- tests/unit/database/node-repository-core.test.ts

Mock Infrastructure

The tests use custom mock implementations:

• MockDatabaseAdapter - Simulates database operations
• MockPreparedStatement - Simulates SQL statement execution
• Mock logger and template sanitizer for external dependencies

This approach ensures tests are fast, reliable, and maintainable.