Unit test coverage for the stats-time-series chart

ui/tests/unit/components/stats-time-series-test.js

+import { test, moduleForComponent } from 'ember-qunit';
+import moment from 'moment';
+import d3Format from 'd3-format';
+import d3TimeFormat from 'd3-time-format';
+
+moduleForComponent('stats-time-series', 'Unit | Component | stats-time-series');
+
+const ts = (offset, resolution = 'm') =>
+  moment()
+    .subtract(offset, resolution)
+    .toDate();
+
+const wideData = [
+  { timestamp: ts(20), value: 0.5 },
+  { timestamp: ts(18), value: 0.5 },
+  { timestamp: ts(16), value: 0.4 },
+  { timestamp: ts(14), value: 0.3 },
+  { timestamp: ts(12), value: 0.9 },
+  { timestamp: ts(10), value: 0.3 },
+  { timestamp: ts(8), value: 0.3 },
+  { timestamp: ts(6), value: 0.4 },
+  { timestamp: ts(4), value: 0.5 },
+  { timestamp: ts(2), value: 0.6 },
+  { timestamp: ts(0), value: 0.6 },
+];
+
+const narrowData = [
+  { timestamp: ts(20, 's'), value: 0.5 },
+  { timestamp: ts(18, 's'), value: 0.5 },
+  { timestamp: ts(16, 's'), value: 0.4 },
+  { timestamp: ts(14, 's'), value: 0.3 },
+  { timestamp: ts(12, 's'), value: 0.9 },
+  { timestamp: ts(10, 's'), value: 0.3 },
+];
+
+test('xFormat is time-formatted for hours, minutes, and seconds', function(assert) {
+  const chart = this.subject();
+
+  chart.set('data', wideData);
+
+  wideData.forEach(datum => {
+    assert.equal(
+      chart.xFormat()(datum.timestamp),
+      d3TimeFormat.timeFormat('%H:%M:%S')(datum.timestamp)
+    );
+  });
+});
+
+test('yFormat is percent-formatted', function(assert) {
+  const chart = this.subject();
+
+  chart.set('data', wideData);
+
+  wideData.forEach(datum => {
+    assert.equal(chart.yFormat()(datum.value), d3Format.format('.1~%')(datum.value));
+  });
+});
+
+test('x scale domain is at least five minutes', function(assert) {
+  const chart = this.subject();
+
+  chart.set('data', narrowData);
+
+  assert.equal(
+    +chart.get('xScale').domain()[0],
+    +moment(Math.max(...narrowData.mapBy('timestamp')))
+      .subtract(5, 'm')
+      .toDate(),
+    'The lower bound of the xScale is 5 minutes ago'
+  );
+});
+
+test('x scale domain is greater than five minutes when the domain of the data is larger than five minutes', function(assert) {
+  const chart = this.subject();
+
+  chart.set('data', wideData);
+
+  assert.equal(
+    +chart.get('xScale').domain()[0],
+    Math.min(...wideData.mapBy('timestamp')),
+    'The lower bound of the xScale is the oldest timestamp in the dataset'
+  );
+});
+
+test('y scale domain is always 0 to 1 (0 to 100%)', function(assert) {
+  const chart = this.subject();
+
+  chart.set('data', wideData);
+
+  assert.deepEqual(
+    [Math.min(...wideData.mapBy('value')), Math.max(...wideData.mapBy('value'))],
+    [0.3, 0.9],
+    'The bounds of the value prop of the dataset is narrower than 0 - 1'
+  );
+
+  assert.deepEqual(
+    chart.get('yScale').domain(),
+    [0, 1],
+    'The bounds of the yScale are still 0 and 1'
+  );
+});