open-nomad/ui/tests/unit/components/line-chart-test.js

import { module, test } from 'qunit';
import { setupTest } from 'ember-qunit';
import d3Format from 'd3-format';

module('Unit | Component | line-chart', function(hooks) {
  setupTest(hooks);

  const data = [
    { foo: 1, bar: 100 },
    { foo: 2, bar: 200 },
    { foo: 3, bar: 300 },
    { foo: 8, bar: 400 },
    { foo: 4, bar: 500 },
  ];

  test('x scale domain is the min and max values in data based on the xProp value', function(assert) {
    const chart = this.owner.factoryFor('component:line-chart').create();

    chart.setProperties({
      xProp: 'foo',
      data,
    });

    let [xDomainLow, xDomainHigh] = chart.get('xScale').domain();
    assert.equal(
      xDomainLow,
      Math.min(...data.mapBy('foo')),
      'Domain lower bound is the lowest foo value'
    );
    assert.equal(
      xDomainHigh,
      Math.max(...data.mapBy('foo')),
      'Domain upper bound is the highest foo value'
    );

    chart.set('data', [...data, { foo: 12, bar: 600 }]);

    [, xDomainHigh] = chart.get('xScale').domain();
    assert.equal(xDomainHigh, 12, 'When the data changes, the xScale is recalculated');
  });

  test('y scale domain uses the max value in the data based off of yProp, but is always zero-based', function(assert) {
    const chart = this.owner.factoryFor('component:line-chart').create();

    chart.setProperties({
      yProp: 'bar',
      data,
    });

    let [yDomainLow, yDomainHigh] = chart.get('yScale').domain();
    assert.equal(yDomainLow, 0, 'Domain lower bound is always 0');
    assert.equal(
      yDomainHigh,
      Math.max(...data.mapBy('bar')),
      'Domain upper bound is the highest bar value'
    );

    chart.set('data', [...data, { foo: 12, bar: 600 }]);

    [, yDomainHigh] = chart.get('yScale').domain();
    assert.equal(yDomainHigh, 600, 'When the data changes, the yScale is recalculated');
  });

  test('the number of yTicks is always odd (to always have a mid-line) and is based off the chart height', function(assert) {
    const chart = this.owner.factoryFor('component:line-chart').create();

    chart.setProperties({
      yProp: 'bar',
      xAxisOffset: 100,
      data,
    });

    assert.equal(chart.get('yTicks').length, 3);

    chart.set('xAxisOffset', 240);
    assert.equal(chart.get('yTicks').length, 5);

    chart.set('xAxisOffset', 241);
    assert.equal(chart.get('yTicks').length, 7);
  });

  test('the values for yTicks are rounded to whole numbers', function(assert) {
    const chart = this.owner.factoryFor('component:line-chart').create();

    chart.setProperties({
      yProp: 'bar',
      xAxisOffset: 100,
      data,
    });

    assert.deepEqual(chart.get('yTicks'), [0, 250, 500]);

    chart.set('xAxisOffset', 240);
    assert.deepEqual(chart.get('yTicks'), [0, 125, 250, 375, 500]);

    chart.set('xAxisOffset', 241);
    assert.deepEqual(chart.get('yTicks'), [0, 83, 167, 250, 333, 417, 500]);
  });

  test('the values for yTicks are fractions when the domain is between 0 and 1', function(assert) {
    const chart = this.owner.factoryFor('component:line-chart').create();

    chart.setProperties({
      yProp: 'bar',
      xAxisOffset: 100,
      data: [
        { foo: 1, bar: 0.1 },
        { foo: 2, bar: 0.2 },
        { foo: 3, bar: 0.3 },
        { foo: 8, bar: 0.4 },
        { foo: 4, bar: 0.5 },
      ],
    });

    assert.deepEqual(chart.get('yTicks'), [0, 0.25, 0.5]);
  });

  test('activeDatumLabel is the xProp value of the activeDatum formatted with xFormat', function(assert) {
    const chart = this.owner.factoryFor('component:line-chart').create();

    chart.setProperties({
      xProp: 'foo',
      yProp: 'bar',
      data,
      activeDatum: data[1],
    });

    assert.equal(
      chart.get('activeDatumLabel'),
      d3Format.format(',')(data[1].foo),
      'activeDatumLabel correctly formats the correct prop of the correct datum'
    );
  });

  test('activeDatumValue is the yProp value of the activeDatum formatted with yFormat', function(assert) {
    const chart = this.owner.factoryFor('component:line-chart').create();

    chart.setProperties({
      xProp: 'foo',
      yProp: 'bar',
      data,
      activeDatum: data[1],
    });

    assert.equal(
      chart.get('activeDatumValue'),
      d3Format.format(',.2~r')(data[1].bar),
      'activeDatumValue correctly formats the correct prop of the correct datum'
    );
  });
});