Duration formatting utility

The cloest Moment.js has is "homanize" which isn't precise enough.

ui/app/helpers/format-duration.js

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+import Helper from '@ember/component/helper';
+import formatDuration from '../utils/format-duration';
+
+function formatDurationHelper([duration], { units }) {
+  return formatDuration(duration, units);
+}
+
+export default Helper.helper(formatDurationHelper);

ui/app/utils/format-duration.js

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+import moment from 'moment';
+
+const allUnits = [
+  { name: 'years', suffix: 'year', inMoment: true, pluralizable: true },
+  { name: 'months', suffix: 'month', inMoment: true, pluralizable: true },
+  { name: 'days', suffix: 'day', inMoment: true, pluralizable: true },
+  { name: 'hours', suffix: 'h', inMoment: true, pluralizable: false },
+  { name: 'minutes', suffix: 'm', inMoment: true, pluralizable: false },
+  { name: 'seconds', suffix: 's', inMoment: true, pluralizable: false },
+  { name: 'milliseconds', suffix: 'ms', inMoment: true, pluralizable: false },
+  { name: 'microseconds', suffix: 'µs', inMoment: false, pluralizable: false },
+  { name: 'nanoseconds', suffix: 'ns', inMoment: false, pluralizable: false },
+];
+
+export default function formatDuration(duration = 0, units = 'ns') {
+  const durationParts = {};
+
+  if (units === 'ns') {
+    durationParts.nanoseconds = duration % 1000;
+    durationParts.microseconds = Math.floor((duration % 1000000) / 1000);
+    duration = Math.floor(duration / 1000000);
+  } else if (units === 'mms') {
+    durationParts.microseconds = duration % 1000;
+    duration = Math.floor(duration / 1000);
+  }
+
+  const momentDuration = moment.duration(duration, ['ns', 'mms'].includes(units) ? 'ms' : units);
+
+  allUnits
+    .filterBy('inMoment')
+    .mapBy('name')
+    .forEach(unit => {
+      durationParts[unit] = momentDuration[unit]();
+    });
+
+  const displayParts = allUnits.reduce((parts, unitType) => {
+    if (durationParts[unitType.name]) {
+      const count = durationParts[unitType.name];
+      const suffix =
+        count === 1 || !unitType.pluralizable ? unitType.suffix : unitType.suffix.pluralize();
+      parts.push(`${count}${unitType.pluralizable ? ' ' : ''}${suffix}`);
+    }
+    return parts;
+  }, []);
+
+  return displayParts.join(' ');
+}

ui/tests/unit/utils/format-duration-test.js

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+import { module, test } from 'ember-qunit';
+import formatDuration from 'nomad-ui/utils/format-duration';
+
+module('Unit | Util | formatDuration');
+
+test('When all units have values, all units are displayed', function(assert) {
+  const expectation = '39 years 1 month 13 days 23h 31m 30s 987ms 654µs 400ns';
+  assert.equal(formatDuration(1234567890987654321), expectation, expectation);
+});
+
+test('Any unit without values gets dropped from the display', function(assert) {
+  const expectation = '14 days 6h 56m 890ms 980µs';
+  assert.equal(formatDuration(1234560890980000), expectation, expectation);
+});
+
+test('The units option allows for units coarser than nanoseconds', function(assert) {
+  const expectation1 = '1s 200ms';
+  const expectation2 = '20m';
+  const expectation3 = '1 month 1 day';
+  assert.equal(formatDuration(1200, 'ms'), expectation1, expectation1);
+  assert.equal(formatDuration(1200, 's'), expectation2, expectation2);
+  assert.equal(formatDuration(32, 'd'), expectation3, expectation3);
+});