n8n-MCP

/** * Unit tests for cache metrics monitoring functionality */ import { describe, it, expect, beforeEach, vi, afterEach } from 'vitest'; import { getInstanceCacheMetrics, getN8nApiClient, clearInstanceCache } from '../../../src/mcp/handlers-n8n-manager'; import { cacheMetrics, getCacheStatistics } from '../../../src/utils/cache-utils'; import { InstanceContext } from '../../../src/types/instance-context'; // Mock the N8nApiClient vi.mock('../../../src/clients/n8n-api-client', () => ({ N8nApiClient: vi.fn().mockImplementation((config) => ({ config, getWorkflows: vi.fn().mockResolvedValue([]), getWorkflow: vi.fn().mockResolvedValue({}), isConnected: vi.fn().mockReturnValue(true) })) })); // Mock logger to reduce noise in tests vi.mock('../../../src/utils/logger', () => { const mockLogger = { debug: vi.fn(), info: vi.fn(), warn: vi.fn(), error: vi.fn() }; return { Logger: vi.fn().mockImplementation(() => mockLogger), logger: mockLogger }; }); describe('Cache Metrics Monitoring', () => { beforeEach(() => { // Clear cache before each test clearInstanceCache(); cacheMetrics.reset(); // Reset environment variables delete process.env.N8N_API_URL; delete process.env.N8N_API_KEY; delete process.env.INSTANCE_CACHE_MAX; delete process.env.INSTANCE_CACHE_TTL_MINUTES; }); afterEach(() => { vi.clearAllMocks(); }); describe('getInstanceCacheStatistics', () => { it('should return initial statistics', () => { const stats = getInstanceCacheMetrics(); expect(stats).toBeDefined(); expect(stats.hits).toBe(0); expect(stats.misses).toBe(0); expect(stats.size).toBe(0); expect(stats.avgHitRate).toBe(0); }); it('should track cache hits and misses', () => { const context1: InstanceContext = { n8nApiUrl: 'https://api1.n8n.cloud', n8nApiKey: 'key1', instanceId: 'instance1' }; const context2: InstanceContext = { n8nApiUrl: 'https://api2.n8n.cloud', n8nApiKey: 'key2', instanceId: 'instance2' }; // First access - cache miss getN8nApiClient(context1); let stats = getInstanceCacheMetrics(); expect(stats.misses).toBe(1); expect(stats.hits).toBe(0); expect(stats.size).toBe(1); // Second access same context - cache hit getN8nApiClient(context1); stats = getInstanceCacheMetrics(); expect(stats.hits).toBe(1); expect(stats.misses).toBe(1); expect(stats.avgHitRate).toBe(0.5); // 1 hit / 2 total // Third access different context - cache miss getN8nApiClient(context2); stats = getInstanceCacheMetrics(); expect(stats.hits).toBe(1); expect(stats.misses).toBe(2); expect(stats.size).toBe(2); expect(stats.avgHitRate).toBeCloseTo(0.333, 2); // 1 hit / 3 total }); it('should track evictions when cache is full', () => { // Note: Cache is created with default size (100), so we need many items to trigger evictions // This test verifies that eviction tracking works, even if we don't hit the limit in practice const initialStats = getInstanceCacheMetrics(); // The cache dispose callback should track evictions when items are removed // For this test, we'll verify the eviction tracking mechanism exists expect(initialStats.evictions).toBeGreaterThanOrEqual(0); // Add a few items to cache const contexts = [ { n8nApiUrl: 'https://api1.n8n.cloud', n8nApiKey: 'key1' }, { n8nApiUrl: 'https://api2.n8n.cloud', n8nApiKey: 'key2' }, { n8nApiUrl: 'https://api3.n8n.cloud', n8nApiKey: 'key3' } ]; contexts.forEach(ctx => getN8nApiClient(ctx)); const stats = getInstanceCacheMetrics(); expect(stats.size).toBe(3); // All items should fit in default cache (max: 100) }); it('should track cache operations over time', () => { const context: InstanceContext = { n8nApiUrl: 'https://api.n8n.cloud', n8nApiKey: 'test-key' }; // Simulate multiple operations for (let i = 0; i < 10; i++) { getN8nApiClient(context); } const stats = getInstanceCacheMetrics(); expect(stats.hits).toBe(9); // First is miss, rest are hits expect(stats.misses).toBe(1); expect(stats.avgHitRate).toBe(0.9); // 9/10 expect(stats.sets).toBeGreaterThanOrEqual(1); }); it('should include timestamp information', () => { const stats = getInstanceCacheMetrics(); expect(stats.createdAt).toBeInstanceOf(Date); expect(stats.lastResetAt).toBeInstanceOf(Date); expect(stats.createdAt.getTime()).toBeLessThanOrEqual(Date.now()); }); it('should track cache clear operations', () => { const context: InstanceContext = { n8nApiUrl: 'https://api.n8n.cloud', n8nApiKey: 'test-key' }; // Add some clients getN8nApiClient(context); // Clear cache clearInstanceCache(); const stats = getInstanceCacheMetrics(); expect(stats.clears).toBe(1); expect(stats.size).toBe(0); }); }); describe('Cache Metrics with Different Scenarios', () => { it('should handle rapid successive requests', () => { const context: InstanceContext = { n8nApiUrl: 'https://api.n8n.cloud', n8nApiKey: 'rapid-test' }; // Simulate rapid requests const promises = []; for (let i = 0; i < 50; i++) { promises.push(Promise.resolve(getN8nApiClient(context))); } return Promise.all(promises).then(() => { const stats = getInstanceCacheMetrics(); expect(stats.hits).toBe(49); // First is miss expect(stats.misses).toBe(1); expect(stats.avgHitRate).toBe(0.98); // 49/50 }); }); it('should track metrics for fallback to environment variables', () => { // Note: Singleton mode (no context) doesn't use the instance cache // This test verifies that cache metrics are not affected by singleton usage const initialStats = getInstanceCacheMetrics(); process.env.N8N_API_URL = 'https://env.n8n.cloud'; process.env.N8N_API_KEY = 'env-key'; // Calls without context use singleton mode (no cache metrics) getN8nApiClient(); getN8nApiClient(); const stats = getInstanceCacheMetrics(); expect(stats.hits).toBe(initialStats.hits); expect(stats.misses).toBe(initialStats.misses); }); it('should maintain separate metrics for different instances', () => { const contexts = Array.from({ length: 5 }, (_, i) => ({ n8nApiUrl: `https://api${i}.n8n.cloud`, n8nApiKey: `key${i}`, instanceId: `instance${i}` })); // Access each instance twice contexts.forEach(ctx => { getN8nApiClient(ctx); // Miss getN8nApiClient(ctx); // Hit }); const stats = getInstanceCacheMetrics(); expect(stats.hits).toBe(5); expect(stats.misses).toBe(5); expect(stats.size).toBe(5); expect(stats.avgHitRate).toBe(0.5); }); it('should handle cache with TTL expiration', () => { // Note: TTL configuration is set when cache is created, not dynamically // This test verifies that TTL-related cache behavior can be tracked const context: InstanceContext = { n8nApiUrl: 'https://ttl-test.n8n.cloud', n8nApiKey: 'ttl-key' }; // First access - miss getN8nApiClient(context); // Second access - hit (within TTL) getN8nApiClient(context); const stats = getInstanceCacheMetrics(); expect(stats.hits).toBe(1); expect(stats.misses).toBe(1); }); }); describe('getCacheStatistics (formatted)', () => { it('should return human-readable statistics', () => { const context: InstanceContext = { n8nApiUrl: 'https://api.n8n.cloud', n8nApiKey: 'test-key' }; // Generate some activity getN8nApiClient(context); getN8nApiClient(context); getN8nApiClient({ ...context, instanceId: 'different' }); const formattedStats = getCacheStatistics(); expect(formattedStats).toContain('Cache Statistics:'); expect(formattedStats).toContain('Runtime:'); expect(formattedStats).toContain('Total Operations:'); expect(formattedStats).toContain('Hit Rate:'); expect(formattedStats).toContain('Current Size:'); expect(formattedStats).toContain('Total Evictions:'); }); it('should show runtime in minutes', () => { const stats = getCacheStatistics(); expect(stats).toMatch(/Runtime: \d+ minutes/); }); it('should show operation counts', () => { const context: InstanceContext = { n8nApiUrl: 'https://api.n8n.cloud', n8nApiKey: 'test-key' }; // Generate operations getN8nApiClient(context); // Set getN8nApiClient(context); // Hit clearInstanceCache(); // Clear const stats = getCacheStatistics(); expect(stats).toContain('Sets: 1'); expect(stats).toContain('Clears: 1'); }); }); describe('Monitoring Performance Impact', () => { it('should have minimal performance overhead', () => { const context: InstanceContext = { n8nApiUrl: 'https://perf-test.n8n.cloud', n8nApiKey: 'perf-key' }; const startTime = performance.now(); // Perform many operations for (let i = 0; i < 1000; i++) { getN8nApiClient(context); } const endTime = performance.now(); const totalTime = endTime - startTime; // Should complete quickly (< 100ms for 1000 operations) expect(totalTime).toBeLessThan(100); // Verify metrics were tracked const stats = getInstanceCacheMetrics(); expect(stats.hits).toBe(999); expect(stats.misses).toBe(1); }); it('should handle concurrent metric updates', async () => { const contexts = Array.from({ length: 10 }, (_, i) => ({ n8nApiUrl: `https://concurrent${i}.n8n.cloud`, n8nApiKey: `key${i}` })); // Concurrent requests const promises = contexts.map(ctx => Promise.resolve(getN8nApiClient(ctx)) ); await Promise.all(promises); const stats = getInstanceCacheMetrics(); expect(stats.misses).toBe(10); expect(stats.size).toBe(10); }); }); describe('Edge Cases and Error Conditions', () => { it('should handle metrics when cache operations fail', () => { const invalidContext = { n8nApiUrl: '', n8nApiKey: '' } as InstanceContext; // This should fail validation but metrics should still work const client = getN8nApiClient(invalidContext); expect(client).toBeNull(); // Metrics should not be affected by validation failures const stats = getInstanceCacheMetrics(); expect(stats).toBeDefined(); }); it('should maintain metrics integrity after reset', () => { const context: InstanceContext = { n8nApiUrl: 'https://reset-test.n8n.cloud', n8nApiKey: 'reset-key' }; // Generate some metrics getN8nApiClient(context); getN8nApiClient(context); // Reset metrics cacheMetrics.reset(); // New operations should start fresh getN8nApiClient(context); const stats = getInstanceCacheMetrics(); expect(stats.hits).toBe(1); // Cache still has item from before reset expect(stats.misses).toBe(0); expect(stats.lastResetAt.getTime()).toBeGreaterThan(stats.createdAt.getTime()); }); it('should handle maximum cache size correctly', () => { // Note: Cache uses default configuration (max: 100) since it's created at module load const contexts = Array.from({ length: 5 }, (_, i) => ({ n8nApiUrl: `https://max${i}.n8n.cloud`, n8nApiKey: `key${i}` })); // Add items within default cache size contexts.forEach(ctx => getN8nApiClient(ctx)); const stats = getInstanceCacheMetrics(); expect(stats.size).toBe(5); // Should fit in default cache expect(stats.maxSize).toBe(100); // Default max size }); }); });