Tests for `PrometheusMetrics` class

spec/javascripts/prometheus_metrics/mock_data.js

+export const metrics = [
+  {
+    group: 'Kubernetes',
+    priority: 1,
+    active_metrics: 4,
+    metrics_missing_requirements: 0,
+  },
+  {
+    group: 'HAProxy',
+    priority: 2,
+    active_metrics: 3,
+    metrics_missing_requirements: 0,
+  },
+  {
+    group: 'Apache',
+    priority: 3,
+    active_metrics: 5,
+    metrics_missing_requirements: 0,
+  },
+];
+
+export const missingVarMetrics = [
+  {
+    group: 'Kubernetes',
+    priority: 1,
+    active_metrics: 4,
+    metrics_missing_requirements: 0,
+  },
+  {
+    group: 'HAProxy',
+    priority: 2,
+    active_metrics: 3,
+    metrics_missing_requirements: 1,
+  },
+  {
+    group: 'Apache',
+    priority: 3,
+    active_metrics: 5,
+    metrics_missing_requirements: 3,
+  },
+];

spec/javascripts/prometheus_metrics/prometheus_metrics_spec.js

+import PrometheusMetrics from '~/prometheus_metrics/prometheus_metrics';
+import { metrics, missingVarMetrics } from './mock_data';
+
+describe('PrometheusMetrics', () => {
+  const FIXTURE = 'services/prometheus_service.html.raw';
+  preloadFixtures(FIXTURE);
+
+  beforeEach(() => {
+    loadFixtures(FIXTURE);
+  });
+
+  describe('constructor', () => {
+    let prometheusMetrics;
+
+    beforeEach(() => {
+      prometheusMetrics = new PrometheusMetrics('.js-prometheus-metrics-monitoring');
+    });
+
+    it('should initialize wrapper element refs on class object', () => {
+      expect(prometheusMetrics.$wrapper).toBeDefined();
+      expect(prometheusMetrics.$monitoredMetricsPanel).toBeDefined();
+      expect(prometheusMetrics.$monitoredMetricsCount).toBeDefined();
+      expect(prometheusMetrics.$monitoredMetricsLoading).toBeDefined();
+      expect(prometheusMetrics.$monitoredMetricsEmpty).toBeDefined();
+      expect(prometheusMetrics.$monitoredMetricsList).toBeDefined();
+      expect(prometheusMetrics.$missingEnvVarPanel).toBeDefined();
+      expect(prometheusMetrics.$panelToggle).toBeDefined();
+      expect(prometheusMetrics.$missingEnvVarMetricCount).toBeDefined();
+      expect(prometheusMetrics.$missingEnvVarMetricsList).toBeDefined();
+    });
+
+    it('should initialize metadata on class object', () => {
+      expect(prometheusMetrics.backOffRequestCounter).toEqual(0);
+      expect(prometheusMetrics.activeMetricsEndpoint).toContain('/test');
+    });
+  });
+
+  describe('populateActiveMetrics', () => {
+    let prometheusMetrics;
+
+    beforeEach(() => {
+      prometheusMetrics = new PrometheusMetrics('.js-prometheus-metrics-monitoring');
+    });
+
+    it('should show monitored metrics list', () => {
+      prometheusMetrics.populateActiveMetrics(metrics);
+
+      const $metricsListLi = prometheusMetrics.$monitoredMetricsList.find('li');
+
+      expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeTruthy();
+      expect(prometheusMetrics.$monitoredMetricsList.hasClass('hidden')).toBeFalsy();
+
+      expect(prometheusMetrics.$monitoredMetricsCount.text()).toEqual('12');
+      expect($metricsListLi.length).toEqual(metrics.length);
+      expect($metricsListLi.first().find('.badge-count').text()).toEqual(`${metrics[0].active_metrics}`);
+    });
+
+    it('should show missing environment variables list', () => {
+      prometheusMetrics.populateActiveMetrics(missingVarMetrics);
+
+      expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeTruthy();
+      expect(prometheusMetrics.$missingEnvVarPanel.hasClass('hidden')).toBeFalsy();
+
+      expect(prometheusMetrics.$missingEnvVarMetricCount.text()).toEqual('2');
+      expect(prometheusMetrics.$missingEnvVarPanel.find('li').length).toEqual(2);
+      expect(prometheusMetrics.$missingEnvVarPanel.find('.flash-container')).toBeDefined();
+    });
+  });
+
+  describe('loadActiveMetrics', () => {
+    let prometheusMetrics;
+
+    beforeEach(() => {
+      prometheusMetrics = new PrometheusMetrics('.js-prometheus-metrics-monitoring');
+    });
+
+    it('should show loader animation while response is being loaded and hide it when request is complete', (done) => {
+      const deferred = $.Deferred();
+      spyOn($, 'getJSON').and.returnValue(deferred.promise());
+
+      prometheusMetrics.loadActiveMetrics();
+
+      expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeFalsy();
+      expect($.getJSON).toHaveBeenCalledWith(prometheusMetrics.activeMetricsEndpoint);
+
+      deferred.resolve({ data: metrics, success: true });
+
+      setTimeout(() => {
+        expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeTruthy();
+        done();
+      });
+    });
+
+    it('should show empty state if response failed to load', (done) => {
+      const deferred = $.Deferred();
+      spyOn($, 'getJSON').and.returnValue(deferred.promise());
+      spyOn(prometheusMetrics, 'populateActiveMetrics');
+
+      prometheusMetrics.loadActiveMetrics();
+
+      deferred.reject();
+
+      setTimeout(() => {
+        expect(prometheusMetrics.$monitoredMetricsLoading.hasClass('hidden')).toBeTruthy();
+        expect(prometheusMetrics.$monitoredMetricsEmpty.hasClass('hidden')).toBeFalsy();
+        done();
+      });
+    });
+
+    it('should populate metrics list once response is loaded', (done) => {
+      const deferred = $.Deferred();
+      spyOn($, 'getJSON').and.returnValue(deferred.promise());
+      spyOn(prometheusMetrics, 'populateActiveMetrics');
+
+      prometheusMetrics.loadActiveMetrics();
+
+      deferred.resolve({ data: metrics, success: true });
+
+      setTimeout(() => {
+        expect(prometheusMetrics.populateActiveMetrics).toHaveBeenCalledWith(metrics);
+        done();
+      });
+    });
+  });
+});