HUMMBL MCP Server

/** * Tests for Prometheus-compatible metrics collection */ import { MetricsCollector, Counter, Gauge, Histogram } from '../src/observability/metrics.js'; describe('MetricsCollector', () => { let metrics: MetricsCollector; beforeEach(() => { metrics = new MetricsCollector(); }); test('creates and increments counters', () => { const counter = metrics.createCounter('test_counter', 'A test counter'); counter.increment(); counter.increment({ method: 'GET' }); counter.add(5, { status: '200' }); const values = counter.getValues(); expect(values).toHaveLength(3); expect(values[0].value).toBe(1); expect(values[1].value).toBe(1); expect(values[1].labels).toEqual({ method: 'GET' }); expect(values[2].value).toBe(5); expect(values[2].labels).toEqual({ status: '200' }); }); test('creates and sets gauges', () => { const gauge = metrics.createGauge('test_gauge', 'A test gauge'); gauge.set(10); expect(gauge.getValue().value).toBe(10); gauge.increment({ type: 'active' }); expect(gauge.getValue().value).toBe(11); expect(gauge.getValue().labels).toEqual({ type: 'active' }); gauge.decrement(); expect(gauge.getValue().value).toBe(10); }); test('creates and observes histograms', () => { const histogram = metrics.createHistogram('test_histogram', 'A test histogram'); histogram.observe(0.1); histogram.observe(0.5); histogram.observe(2.5); const data = histogram.getData(); expect(data.count).toBe(3); expect(data.sum).toBe(3.1); expect(data.buckets[0].count).toBe(1); // 0.1 expect(data.buckets[1].count).toBe(2); // 0.5 expect(data.buckets[3].count).toBe(3); // 2.5 }); test('exports Prometheus format', () => { const counter = metrics.createCounter('http_requests_total', 'Total HTTP requests'); const gauge = metrics.createGauge('active_connections', 'Active connections'); const histogram = metrics.createHistogram('request_duration_seconds', 'Request duration'); counter.increment({ method: 'GET', status: '200' }); gauge.set(5); histogram.observe(0.25); const prometheusOutput = metrics.exportPrometheus(); expect(prometheusOutput).toContain('# HELP http_requests_total Total HTTP requests'); expect(prometheusOutput).toContain('# TYPE http_requests_total counter'); expect(prometheusOutput).toContain('http_requests_total{method="GET",status="200"} 1'); expect(prometheusOutput).toContain('# HELP active_connections Active connections'); expect(prometheusOutput).toContain('# TYPE active_connections gauge'); expect(prometheusOutput).toContain('active_connections 5'); expect(prometheusOutput).toContain('# HELP request_duration_seconds Request duration'); expect(prometheusOutput).toContain('# TYPE request_duration_seconds histogram'); expect(prometheusOutput).toContain('request_duration_seconds_count 1'); expect(prometheusOutput).toContain('request_duration_seconds_sum 0.25'); }); test('recordLatency updates histogram', () => { const histogram = metrics.createHistogram('mcp_operation_duration_seconds', 'Operation duration'); metrics.recordLatency('operation', 250); // 250ms = 0.25s const data = histogram.getData(); expect(data.count).toBe(1); expect(data.sum).toBe(0.25); }); test('incrementCounter and setGauge convenience methods', () => { const counter = metrics.createCounter('test_counter', 'Test counter'); const gauge = metrics.createGauge('test_gauge', 'Test gauge'); metrics.incrementCounter('test_counter', { type: 'test' }); metrics.setGauge('test_gauge', 42); const counterValues = counter.getValues(); expect(counterValues[0].value).toBe(1); expect(counterValues[0].labels).toEqual({ type: 'test' }); expect(gauge.getValue().value).toBe(42); }); test('reset clears all metrics', () => { const counter = metrics.createCounter('test_counter', 'Test counter'); const gauge = metrics.createGauge('test_gauge', 'Test gauge'); const histogram = metrics.createHistogram('test_histogram', 'Test histogram'); counter.increment(); gauge.set(10); histogram.observe(1.0); metrics.reset(); expect(counter.getValues()).toHaveLength(0); expect(gauge.getValue().value).toBe(0); expect(histogram.getData().count).toBe(0); }); }); describe('Pre-defined metrics', () => { test('session metrics are properly initialized', async () => { // Import the pre-defined metrics const { sessionCreateCounter, sessionCreateDuration, activeSessionsGauge } = await import('../src/observability/metrics.js'); expect(sessionCreateCounter).toBeDefined(); expect(sessionCreateDuration).toBeDefined(); expect(activeSessionsGauge).toBeDefined(); // Test that they can be used sessionCreateCounter.increment({ result: 'success' }); sessionCreateDuration.observe(0.1, { result: 'success' }); activeSessionsGauge.set(5); expect(sessionCreateCounter.getValues()).toHaveLength(1); expect(activeSessionsGauge.getValue().value).toBe(5); }); });