Unit test coverage for the ScaleEventsChart data domain logic

ui/app/components/scale-events-chart.js

@@ -12,7 +12,7 @@ export default class ScaleEventsChart extends Component {
 
   @computed('events.[]')
   get data() {
-    const data = this.events.filterBy('hasCount');
+    const data = this.events.filterBy('hasCount').sortBy('time');
 
     // Extend the domain of the chart to the current time
     data.push({
@@ -29,7 +29,7 @@ export default class ScaleEventsChart extends Component {
       });
     }
 
-    return data.sortBy('time');
+    return data;
   }
 
   @computed('events.[]')

ui/tests/unit/components/scale-events-chart-test.js

@@ -0,0 +1,68 @@
+import { module, test } from 'qunit';
+import { setupTest } from 'ember-qunit';
+import sinon from 'sinon';
+
+module('Unit | Component | scale-events-chart', function(hooks) {
+  setupTest(hooks);
+
+  hooks.beforeEach(function() {
+    this.refTime = new Date();
+    this.clock = sinon.useFakeTimers(this.refTime);
+  });
+
+  hooks.afterEach(function() {
+    this.clock.restore();
+    delete this.refTime;
+  });
+
+  test('the current date is appended as a datum for the line chart to render', function(assert) {
+    const chart = this.owner.factoryFor('component:scale-events-chart').create();
+    const events = [
+      { time: new Date('2020-08-02T04:06:00'), count: 2, hasCount: true },
+      { time: new Date('2020-08-01T04:06:00'), count: 2, hasCount: true },
+    ];
+
+    chart.set('events', events);
+
+    assert.equal(chart.data.length, events.length + 1);
+    assert.deepEqual(chart.data.slice(0, events.length), events.sortBy('time'));
+
+    const appendedDatum = chart.data[chart.data.length - 1];
+    assert.equal(appendedDatum.count, events.sortBy('time').lastObject.count);
+    assert.equal(+appendedDatum.time, +this.refTime);
+  });
+
+  test('if the earliest annotation is outside the domain of the events, the earliest annotation time is added as a datum for the line chart to render', function(assert) {
+    const chart = this.owner.factoryFor('component:scale-events-chart').create();
+    const annotationOutside = [
+      { time: new Date('2020-08-01T04:06:00'), hasCount: false, error: true },
+      { time: new Date('2020-08-02T04:06:00'), count: 2, hasCount: true },
+      { time: new Date('2020-08-03T04:06:00'), count: 2, hasCount: true },
+    ];
+    const annotationInside = [
+      { time: new Date('2020-08-02T04:06:00'), count: 2, hasCount: true },
+      { time: new Date('2020-08-02T12:06:00'), hasCount: false, error: true },
+      { time: new Date('2020-08-03T04:06:00'), count: 2, hasCount: true },
+    ];
+
+    chart.set('events', annotationOutside);
+
+    assert.equal(chart.data.length, annotationOutside.length + 1);
+    assert.deepEqual(
+      chart.data.slice(1, annotationOutside.length),
+      annotationOutside.filterBy('hasCount')
+    );
+
+    const appendedDatum = chart.data[0];
+    assert.equal(appendedDatum.count, annotationOutside[1].count);
+    assert.equal(+appendedDatum.time, +annotationOutside[0].time);
+
+    chart.set('events', annotationInside);
+
+    assert.equal(chart.data.length, annotationOutside.length);
+    assert.deepEqual(
+      chart.data.slice(0, annotationOutside.length - 1),
+      annotationOutside.filterBy('hasCount')
+    );
+  });
+});