scale.time.tests.js

// Time scale tests
describe('Time scale tests', function() {
	function createScale(data, options, dimensions) {
		var scaleID = 'myScale';
		var mockContext = window.createMockContext();
		var Constructor = Chart.scaleService.getScaleConstructor('time');
		var scale = new Constructor({
			ctx: mockContext,
			options: options,
			chart: {
				data: data
			},
			id: scaleID
		});

		var width = (dimensions && dimensions.width) || 400;
		var height = (dimensions && dimensions.height) || 50;
		scale.update(width, height);
		return scale;
	}

	function getTicksLabels(scale) {
		return scale.ticks;
	}

	beforeEach(function() {
		// Need a time matcher for getValueFromPixel
		jasmine.addMatchers({
			toBeCloseToTime: function() {
				return {
					compare: function(actual, expected) {
						var result = false;

						var diff = actual.diff(expected.value, expected.unit, true);
						result = Math.abs(diff) < (expected.threshold !== undefined ? expected.threshold : 0.01);

						return {
							pass: result
						};
					}
				};
			}
		});
	});

	it('should load moment.js as a dependency', function() {
		expect(window.moment).not.toBe(undefined);
	});

	it('should register the constructor with the scale service', function() {
		var Constructor = Chart.scaleService.getScaleConstructor('time');
		expect(Constructor).not.toBe(undefined);
		expect(typeof Constructor).toBe('function');
	});

	it('should have the correct default config', function() {
		var defaultConfig = Chart.scaleService.getScaleDefaults('time');
		expect(defaultConfig).toEqual({
			display: true,
			gridLines: {
				color: 'rgba(0, 0, 0, 0.1)',
				drawBorder: true,
				drawOnChartArea: true,
				drawTicks: true,
				tickMarkLength: 10,
				lineWidth: 1,
				offsetGridLines: false,
				display: true,
				zeroLineColor: 'rgba(0,0,0,0.25)',
				zeroLineWidth: 1,
				zeroLineBorderDash: [],
				zeroLineBorderDashOffset: 0.0,
				borderDash: [],
				borderDashOffset: 0.0
			},
			position: 'bottom',
			offset: false,
			scaleLabel: Chart.defaults.scale.scaleLabel,
			bounds: 'data',
			distribution: 'linear',
			adapters: {},
			ticks: {
				beginAtZero: false,
				minRotation: 0,
				maxRotation: 50,
				mirror: false,
				source: 'auto',
				padding: 0,
				reverse: false,
				display: true,
				callback: defaultConfig.ticks.callback, // make this nicer, then check explicitly below,
				autoSkip: false,
				autoSkipPadding: 0,
				labelOffset: 0,
				minor: {},
				major: {
					enabled: false
				},
			},
			time: {
				parser: false,
				unit: false,
				round: false,
				isoWeekday: false,
				displayFormat: false,
				minUnit: 'millisecond',
				displayFormats: {}
			}
		});

		// Is this actually a function
		expect(defaultConfig.ticks.callback).toEqual(jasmine.any(Function));
	});

	describe('when given inputs of different types', function() {
		// Helper to build date objects
		function newDateFromRef(days) {
			return moment('01/01/2015 12:00', 'DD/MM/YYYY HH:mm').add(days, 'd').toDate();
		}

		it('should accept labels as strings', function() {
			var mockData = {
				labels: ['2015-01-01T12:00:00', '2015-01-02T21:00:00', '2015-01-03T22:00:00', '2015-01-05T23:00:00', '2015-01-07T03:00', '2015-01-08T10:00', '2015-01-10T12:00'], // days
			};

			var scaleOptions = Chart.scaleService.getScaleDefaults('time');
			var scale = createScale(mockData, scaleOptions, {width: 1000, height: 200});
			var ticks = getTicksLabels(scale);

			// `bounds === 'data'`: first and last ticks removed since outside the data range
			expect(ticks).toEqual(['Jan 2', 'Jan 3', 'Jan 4', 'Jan 5', 'Jan 6', 'Jan 7', 'Jan 8', 'Jan 9', 'Jan 10']);
		});

		it('should accept labels as date objects', function() {
			var mockData = {
				labels: [newDateFromRef(0), newDateFromRef(1), newDateFromRef(2), newDateFromRef(4), newDateFromRef(6), newDateFromRef(7), newDateFromRef(9)], // days
			};
			var scale = createScale(mockData, Chart.scaleService.getScaleDefaults('time'), {width: 1000, height: 200});
			var ticks = getTicksLabels(scale);

			// `bounds === 'data'`: first and last ticks removed since outside the data range
			expect(ticks).toEqual(['Jan 2', 'Jan 3', 'Jan 4', 'Jan 5', 'Jan 6', 'Jan 7', 'Jan 8', 'Jan 9', 'Jan 10']);
		});

		it('should accept data as xy points', function() {
			var chart = window.acquireChart({
				type: 'line',
				data: {
					datasets: [{
						xAxisID: 'xScale0',
						data: [{
							x: newDateFromRef(0),
							y: 1
						}, {
							x: newDateFromRef(1),
							y: 10
						}, {
							x: newDateFromRef(2),
							y: 0
						}, {
							x: newDateFromRef(4),
							y: 5
						}, {
							x: newDateFromRef(6),
							y: 77
						}, {
							x: newDateFromRef(7),
							y: 9
						}, {
							x: newDateFromRef(9),
							y: 5
						}]
					}],
				},
				options: {
					scales: {
						xAxes: [{
							id: 'xScale0',
							type: 'time',
							position: 'bottom'
						}],
					}
				}
			}, {canvas: {width: 800, height: 200}});

			var xScale = chart.scales.xScale0;
			var ticks = getTicksLabels(xScale);

			// `bounds === 'data'`: first and last ticks removed since outside the data range
			expect(ticks).toEqual(['Jan 2', 'Jan 3', 'Jan 4', 'Jan 5', 'Jan 6', 'Jan 7', 'Jan 8', 'Jan 9', 'Jan 10']);
		});

		it('should accept data as ty points', function() {
			var chart = window.acquireChart({
				type: 'line',
				data: {
					datasets: [{
						xAxisID: 'tScale0',
						data: [{
							t: newDateFromRef(0),
							y: 1
						}, {
							t: newDateFromRef(1),
							y: 10
						}, {
							t: newDateFromRef(2),
							y: 0
						}, {
							t: newDateFromRef(4),
							y: 5
						}, {
							t: newDateFromRef(6),
							y: 77
						}, {
							t: newDateFromRef(7),
							y: 9
						}, {
							t: newDateFromRef(9),
							y: 5
						}]
					}],
				},
				options: {
					scales: {
						xAxes: [{
							id: 'tScale0',
							type: 'time',
							position: 'bottom'
						}],
					}
				}
			}, {canvas: {width: 800, height: 200}});

			var tScale = chart.scales.tScale0;
			var ticks = getTicksLabels(tScale);

			// `bounds === 'data'`: first and last ticks removed since outside the data range
			expect(ticks).toEqual(['Jan 2', 'Jan 3', 'Jan 4', 'Jan 5', 'Jan 6', 'Jan 7', 'Jan 8', 'Jan 9', 'Jan 10']);
		});
	});

	it('should allow custom time parsers', function() {
		var chart = window.acquireChart({
			type: 'line',
			data: {
				labels: ['foo', 'bar'],
				datasets: [{
					xAxisID: 'xScale0',
					data: [0, 1]
				}],
			},
			options: {
				scales: {
					xAxes: [{
						id: 'xScale0',
						type: 'time',
						position: 'bottom',
						time: {
							unit: 'day',
							round: true,
							parser: function(label) {
								return label === 'foo' ?
									moment('2000/01/02', 'YYYY/MM/DD') :
									moment('2016/05/08', 'YYYY/MM/DD');
							}
						},
						ticks: {
							source: 'labels'
						}
					}],
				}
			}
		});

		// Counts down because the lines are drawn top to bottom
		var xScale = chart.scales.xScale0;

		// Counts down because the lines are drawn top to bottom
		expect(xScale.ticks[0]).toBe('Jan 2');
		expect(xScale.ticks[1]).toBe('May 8');
	});

	it('should build ticks using the config unit', function() {
		var mockData = {
			labels: ['2015-01-01T20:00:00', '2015-01-02T21:00:00'], // days
		};

		var config = Chart.helpers.clone(Chart.scaleService.getScaleDefaults('time'));
		config.time.unit = 'hour';

		var scale = createScale(mockData, config, {width: 2500, height: 200});
		var ticks = getTicksLabels(scale);

		expect(ticks).toEqual(['8PM', '9PM', '10PM', '11PM', '12AM', '1AM', '2AM', '3AM', '4AM', '5AM', '6AM', '7AM', '8AM', '9AM', '10AM', '11AM', '12PM', '1PM', '2PM', '3PM', '4PM', '5PM', '6PM', '7PM', '8PM', '9PM']);
	});

	it('should build ticks honoring the minUnit', function() {
		var mockData = {
			labels: ['2015-01-01T20:00:00', '2015-01-02T21:00:00'], // days
		};

		var config = Chart.helpers.mergeIf({
			bounds: 'ticks',
			time: {
				minUnit: 'day'
			}
		}, Chart.scaleService.getScaleDefaults('time'));

		var scale = createScale(mockData, config);
		var ticks = getTicksLabels(scale);

		expect(ticks).toEqual(['Jan 1', 'Jan 2', 'Jan 3']);
	});

	it('should correctly determine the unit', function() {
		var date = moment('Jan 01 1990', 'MMM DD YYYY');
		var data = [];
		for (var i = 0; i < 60; i++) {
			data.push({x: date.valueOf(), y: Math.random()});
			date = date.clone().add(1, 'month');
		}

		var chart = window.acquireChart({
			type: 'line',
			data: {
				datasets: [{
					xAxisID: 'xScale0',
					data: data
				}],
			},
			options: {
				scales: {
					xAxes: [{
						id: 'xScale0',
						type: 'time',
						ticks: {
							source: 'data',
							autoSkip: true
						}
					}],
				}
			}
		});

		var scale = chart.scales.xScale0;

		expect(scale._unit).toEqual('month');
	});

	it('should build ticks based on the appropriate label capacity', function() {
		var mockData = {
			labels: [
				'2012-01-01', '2013-01-01', '2014-01-01', '2015-01-01',
				'2016-01-01', '2017-01-01', '2018-01-01', '2019-01-01'
			]
		};

		var config = Chart.helpers.mergeIf({
			time: {
				unit: 'year'
			}
		}, Chart.scaleService.getScaleDefaults('time'));

		var scale = createScale(mockData, config);
		var ticks = getTicksLabels(scale);

		expect(ticks).toEqual(['2012', '2013', '2014', '2015', '2016', '2017', '2018', '2019']);
	});

	it('should build ticks using the config diff', function() {
		var mockData = {
			labels: ['2015-01-01T20:00:00', '2015-02-02T21:00:00', '2015-02-21T01:00:00'], // days
		};

		var config = Chart.helpers.mergeIf({
			bounds: 'ticks',
			time: {
				unit: 'week',
				round: 'week'
			}
		}, Chart.scaleService.getScaleDefaults('time'));

		var scale = createScale(mockData, config, {width: 800, height: 200});
		var ticks = getTicksLabels(scale);

		// last date is feb 15 because we round to start of week
		expect(ticks).toEqual(['Dec 28, 2014', 'Jan 4, 2015', 'Jan 11, 2015', 'Jan 18, 2015', 'Jan 25, 2015', 'Feb 1, 2015', 'Feb 8, 2015', 'Feb 15, 2015']);
	});

	describe('config step size', function() {
		it('should use the stepSize property', function() {
			var mockData = {
				labels: ['2015-01-01T20:00:00', '2015-01-01T21:00:00'],
			};

			var config = Chart.helpers.mergeIf({
				bounds: 'ticks',
				time: {
					unit: 'hour',
					stepSize: 2
				}
			}, Chart.scaleService.getScaleDefaults('time'));

			var scale = createScale(mockData, config, {width: 2500, height: 200});
			var ticks = getTicksLabels(scale);

			expect(ticks).toEqual(['8PM', '10PM']);
		});
	});

	describe('when specifying limits', function() {
		var mockData = {
			labels: ['2015-01-01T20:00:00', '2015-01-02T20:00:00', '2015-01-03T20:00:00'],
		};

		var config;
		beforeEach(function() {
			config = Chart.helpers.clone(Chart.scaleService.getScaleDefaults('time'));
			config.ticks.source = 'labels';
			config.time.unit = 'day';
		});

		it('should use the min option when less than first label for building ticks', function() {
			config.ticks.min = '2014-12-29T04:00:00';

			var scale = createScale(mockData, config);
			expect(scale.ticks[0]).toEqual('Jan 1');
		});

		it('should use the min option when greater than first label for building ticks', function() {
			config.ticks.min = '2015-01-02T04:00:00';

			var scale = createScale(mockData, config);
			expect(scale.ticks[0]).toEqual('Jan 2');
		});

		it('should use the max option when greater than last label for building ticks', function() {
			config.ticks.max = '2015-01-05T06:00:00';

			var scale = createScale(mockData, config);
			expect(scale.ticks[scale.ticks.length - 1]).toEqual('Jan 3');
		});

		it('should use the max option when less than last label for building ticks', function() {
			config.ticks.max = '2015-01-02T23:00:00';

			var scale = createScale(mockData, config);
			expect(scale.ticks[scale.ticks.length - 1]).toEqual('Jan 2');
		});
	});

	describe('when specifying limits in a deprecated fashion', function() {
		var mockData = {
			labels: ['2015-01-01T20:00:00', '2015-01-02T20:00:00', '2015-01-03T20:00:00'],
		};

		var config;
		beforeEach(function() {
			config = Chart.helpers.clone(Chart.scaleService.getScaleDefaults('time'));
			config.ticks.source = 'labels';
			config.time.unit = 'day';
		});

		it('should use the min option when less than first label for building ticks', function() {
			config.ticks.min = '2014-12-29T04:00:00';

			var scale = createScale(mockData, config);
			expect(scale.ticks[0]).toEqual('Jan 1');
		});

		it('should use the min option when greater than first label for building ticks', function() {
			config.ticks.min = '2015-01-02T04:00:00';

			var scale = createScale(mockData, config);
			expect(scale.ticks[0]).toEqual('Jan 2');
		});

		it('should use the max option when greater than last label for building ticks', function() {
			config.ticks.max = '2015-01-05T06:00:00';

			var scale = createScale(mockData, config);
			expect(scale.ticks[scale.ticks.length - 1]).toEqual('Jan 3');
		});

		it('should use the max option when less than last label for building ticks', function() {
			config.ticks.max = '2015-01-02T23:00:00';

			var scale = createScale(mockData, config);
			expect(scale.ticks[scale.ticks.length - 1]).toEqual('Jan 2');
		});
	});

	it('should use the isoWeekday option', function() {
		var mockData = {
			labels: [
				'2015-01-01T20:00:00', // Thursday
				'2015-01-02T20:00:00', // Friday
				'2015-01-03T20:00:00' // Saturday
			]
		};

		var config = Chart.helpers.mergeIf({
			bounds: 'ticks',
			time: {
				unit: 'week',
				isoWeekday: 3 // Wednesday
			}
		}, Chart.scaleService.getScaleDefaults('time'));

		var scale = createScale(mockData, config);
		var ticks = getTicksLabels(scale);

		expect(ticks).toEqual(['Dec 31, 2014', 'Jan 7, 2015']);
	});

	describe('when rendering several days', function() {
		beforeEach(function() {
			this.chart = window.acquireChart({
				type: 'line',
				data: {
					datasets: [{
						xAxisID: 'xScale0',
						data: []
					}],
					labels: [
						'2015-01-01T20:00:00',
						'2015-01-02T21:00:00',
						'2015-01-03T22:00:00',
						'2015-01-05T23:00:00',
						'2015-01-07T03:00',
						'2015-01-08T10:00',
						'2015-01-10T12:00'
					]
				},
				options: {
					scales: {
						xAxes: [{
							id: 'xScale0',
							type: 'time',
							position: 'bottom'
						}],
					}
				}
			});

			this.scale = this.chart.scales.xScale0;
		});

		it('should be bounded by the nearest week beginnings', function() {
			var chart = this.chart;
			var scale = this.scale;
			expect(scale.getValueForPixel(scale.left)).toBeGreaterThan(moment(chart.data.labels[0]).startOf('week'));
			expect(scale.getValueForPixel(scale.right)).toBeLessThan(moment(chart.data.labels[chart.data.labels.length - 1]).add(1, 'week').endOf('week'));
		});

		it('should convert between screen coordinates and times', function() {
			var chart = this.chart;
			var scale = this.scale;
			var timeRange = moment(scale.max).valueOf() - moment(scale.min).valueOf();
			var msPerPix = timeRange / scale.width;
			var firstPointOffsetMs = moment(chart.config.data.labels[0]).valueOf() - scale.min;
			var firstPointPixel = scale.left + firstPointOffsetMs / msPerPix;
			var lastPointOffsetMs = moment(chart.config.data.labels[chart.config.data.labels.length - 1]).valueOf() - scale.min;
			var lastPointPixel = scale.left + lastPointOffsetMs / msPerPix;

			expect(scale.getPixelForValue('', 0, 0)).toBeCloseToPixel(firstPointPixel);
			expect(scale.getPixelForValue(chart.data.labels[0])).toBeCloseToPixel(firstPointPixel);
			expect(scale.getValueForPixel(firstPointPixel)).toBeCloseToTime({
				value: moment(chart.data.labels[0]),
				unit: 'hour',
			});

			expect(scale.getPixelForValue('', 6, 0)).toBeCloseToPixel(lastPointPixel);
			expect(scale.getValueForPixel(lastPointPixel)).toBeCloseToTime({
				value: moment(chart.data.labels[6]),
				unit: 'hour'
			});
		});
	});

	describe('when rendering several years', function() {
		beforeEach(function() {
			this.chart = window.acquireChart({
				type: 'line',
				data: {
					labels: ['2005-07-04', '2017-01-20'],
				},
				options: {
					scales: {
						xAxes: [{
							id: 'xScale0',
							type: 'time',
							bounds: 'ticks',
							position: 'bottom'
						}],
					}
				}
			}, {canvas: {width: 800, height: 200}});

			this.scale = this.chart.scales.xScale0;
		});

		it('should be bounded by nearest step\'s year start and end', function() {
			var scale = this.scale;
			var ticks = scale.getTicks();
			var step = ticks[1].value - ticks[0].value;
			var stepsAmount = Math.floor((scale.max - scale.min) / step);

			expect(scale.getValueForPixel(scale.left)).toBeCloseToTime({
				value: moment(scale.min).startOf('year'),
				unit: 'hour',
			});
			expect(scale.getValueForPixel(scale.right)).toBeCloseToTime({
				value: moment(scale.min + step * stepsAmount).endOf('year'),
				unit: 'hour',
			});
		});

		it('should build the correct ticks', function() {
			// Where 'correct' is a two year spacing.
			expect(getTicksLabels(this.scale)).toEqual(['2005', '2007', '2009', '2011', '2013', '2015', '2017', '2019']);
		});

		it('should have ticks with accurate labels', function() {
			var scale = this.scale;
			var ticks = scale.getTicks();
			var pixelsPerYear = scale.width / 14;

			for (var i = 0; i < ticks.length - 1; i++) {
				var offset = 2 * pixelsPerYear * i;
				expect(scale.getValueForPixel(scale.left + offset)).toBeCloseToTime({
					value: moment(ticks[i].label + '-01-01'),
					unit: 'day',
					threshold: 0.5,
				});
			}
		});
	});

	it('should get the correct label for a data value', function() {
		var chart = window.acquireChart({
			type: 'line',
			data: {
				datasets: [{
					xAxisID: 'xScale0',
					data: [null, 10, 3]
				}],
				labels: ['2015-01-01T20:00:00', '2015-01-02T21:00:00', '2015-01-03T22:00:00', '2015-01-05T23:00:00', '2015-01-07T03:00', '2015-01-08T10:00', '2015-01-10T12:00'], // days
			},
			options: {
				scales: {
					xAxes: [{
						id: 'xScale0',
						type: 'time',
						position: 'bottom'
					}],
				}
			}
		});

		var xScale = chart.scales.xScale0;
		expect(xScale.getLabelForIndex(0, 0)).toBeTruthy();
		expect(xScale.getLabelForIndex(0, 0)).toBe('2015-01-01T20:00:00');
		expect(xScale.getLabelForIndex(6, 0)).toBe('2015-01-10T12:00');
	});

	describe('when ticks.callback is specified', function() {
		beforeEach(function() {
			this.chart = window.acquireChart({
				type: 'line',
				data: {
					datasets: [{
						xAxisID: 'xScale0',
						data: [0, 0]
					}],
					labels: ['2015-01-01T20:00:00', '2015-01-01T20:01:00']
				},
				options: {
					scales: {
						xAxes: [{
							id: 'xScale0',
							type: 'time',
							time: {
								displayFormats: {
									second: 'h:mm:ss'
								}
							},
							ticks: {
								callback: function(value) {
									return '<' + value + '>';
								}
							}
						}]
					}
				}
			});
			this.scale = this.chart.scales.xScale0;
		});

		it('should get the correct labels for ticks', function() {
			var scale = this.scale;

			expect(scale._ticks.map(function(tick) {
				return tick.major;
			})).toEqual([true, false, false, false, false, false, true]);
			expect(scale.ticks).toEqual(['<8:00:00>', '<8:00:10>', '<8:00:20>', '<8:00:30>', '<8:00:40>', '<8:00:50>', '<8:01:00>']);
		});

		it('should update ticks.callback correctly', function() {
			var chart = this.chart;
			var scale = this.scale;

			chart.options.scales.xAxes[0].ticks.callback = function(value) {
				return '{' + value + '}';
			};
			chart.update();
			expect(scale.ticks).toEqual(['{8:00:00}', '{8:00:10}', '{8:00:20}', '{8:00:30}', '{8:00:40}', '{8:00:50}', '{8:01:00}']);
		});
	});

	describe('when ticks.major.callback and ticks.minor.callback are specified', function() {
		beforeEach(function() {
			this.chart = window.acquireChart({
				type: 'line',
				data: {
					datasets: [{
						xAxisID: 'xScale0',
						data: [0, 0]
					}],
					labels: ['2015-01-01T20:00:00', '2015-01-01T20:01:00']
				},
				options: {
					scales: {
						xAxes: [{
							id: 'xScale0',
							type: 'time',
							ticks: {
								callback: function(value) {
									return '<' + value + '>';
								},
								major: {
									enabled: true,
									callback: function(value) {
										return '[[' + value + ']]';
									}
								},
								minor: {
									callback: function(value) {
										return '(' + value + ')';
									}
								}
							}
						}]
					}
				}
			});
			this.scale = this.chart.scales.xScale0;
		});

		it('should get the correct labels for major and minor ticks', function() {
			var scale = this.scale;

			expect(scale._ticks.map(function(tick) {
				return tick.major;
			})).toEqual([true, false, false, false, false, false, true]);
			expect(scale.ticks).toEqual(['[[8:00 pm]]', '(8:00:10 pm)', '(8:00:20 pm)', '(8:00:30 pm)', '(8:00:40 pm)', '(8:00:50 pm)', '[[8:01 pm]]']);
		});

		it('should only use ticks.minor callback if ticks.major.enabled is false', function() {
			var chart = this.chart;
			var scale = this.scale;

			chart.options.scales.xAxes[0].ticks.major.enabled = false;
			chart.update();
			expect(scale.ticks).toEqual(['(8:00:00 pm)', '(8:00:10 pm)', '(8:00:20 pm)', '(8:00:30 pm)', '(8:00:40 pm)', '(8:00:50 pm)', '(8:01:00 pm)']);
		});

		it('should use ticks.callback if ticks.major.callback is omitted', function() {
			var chart = this.chart;
			var scale = this.scale;

			chart.options.scales.xAxes[0].ticks.major.callback = undefined;
			chart.update();
			expect(scale.ticks).toEqual(['<8:00 pm>', '(8:00:10 pm)', '(8:00:20 pm)', '(8:00:30 pm)', '(8:00:40 pm)', '(8:00:50 pm)', '<8:01 pm>']);
		});

		it('should use ticks.callback if ticks.minor.callback is omitted', function() {
			var chart = this.chart;
			var scale = this.scale;

			chart.options.scales.xAxes[0].ticks.minor.callback = undefined;
			chart.update();
			expect(scale.ticks).toEqual(['[[8:00 pm]]', '<8:00:10 pm>', '<8:00:20 pm>', '<8:00:30 pm>', '<8:00:40 pm>', '<8:00:50 pm>', '[[8:01 pm]]']);
		});
	});

	it('should get the correct label when time is specified as a string', function() {
		var chart = window.acquireChart({
			type: 'line',
			data: {
				datasets: [{
					xAxisID: 'xScale0',
					data: [{t: '2015-01-01T20:00:00', y: 10}, {t: '2015-01-02T21:00:00', y: 3}]
				}],
			},
			options: {
				scales: {
					xAxes: [{
						id: 'xScale0',
						type: 'time',
						position: 'bottom'
					}],
				}
			}
		});

		var xScale = chart.scales.xScale0;
		expect(xScale.getLabelForIndex(0, 0)).toBeTruthy();
		expect(xScale.getLabelForIndex(0, 0)).toBe('2015-01-01T20:00:00');
	});

	it('should get the correct label for a timestamp', function() {
		var chart = window.acquireChart({
			type: 'line',
			data: {
				datasets: [{
					xAxisID: 'xScale0',
					data: [
						{t: +new Date('2018-01-08 05:14:23.234'), y: 10},
						{t: +new Date('2018-01-09 06:17:43.426'), y: 3}
					]
				}],
			},
			options: {
				scales: {
					xAxes: [{
						id: 'xScale0',
						type: 'time',
						position: 'bottom'
					}],
				}
			}
		});

		var xScale = chart.scales.xScale0;
		var label = xScale.getLabelForIndex(0, 0);
		expect(label).toEqual('Jan 8, 2018, 5:14:23 am');
	});

	it('should get the correct pixel for only one data in the dataset', function() {
		var chart = window.acquireChart({
			type: 'line',
			data: {
				labels: ['2016-05-27'],
				datasets: [{
					xAxisID: 'xScale0',
					data: [5]
				}]
			},
			options: {
				scales: {
					xAxes: [{
						id: 'xScale0',
						display: true,
						type: 'time'
					}]
				}
			}
		});

		var xScale = chart.scales.xScale0;
		var pixel = xScale.getPixelForValue('', 0, 0);

		expect(xScale.getValueForPixel(pixel).valueOf()).toEqual(moment(chart.data.labels[0]).valueOf());
	});

	it('does not create a negative width chart when hidden', function() {
		var chart = window.acquireChart({
			type: 'line',
			data: {
				datasets: [{
					data: []
				}]
			},
			options: {
				scales: {
					xAxes: [{
						type: 'time',
						ticks: {
							min: moment().subtract(1, 'months'),
							max: moment(),
						}
					}],
				},
				responsive: true,
			},
		}, {
			wrapper: {
				style: 'display: none',
			},
		});
		expect(chart.scales['y-axis-0'].width).toEqual(0);
		expect(chart.scales['y-axis-0'].maxWidth).toEqual(0);
		expect(chart.width).toEqual(0);
	});

	describe('when ticks.source', function() {
		describe('is "labels"', function() {
			beforeEach(function() {
				this.chart = window.acquireChart({
					type: 'line',
					data: {
						labels: ['2017', '2019', '2020', '2025', '2042'],
						datasets: [{data: [0, 1, 2, 3, 4, 5]}]
					},
					options: {
						scales: {
							xAxes: [{
								id: 'x',
								type: 'time',
								time: {
									parser: 'YYYY'
								},
								ticks: {
									source: 'labels'
								}
							}]
						}
					}
				});
			});

			it ('should generate ticks from "data.labels"', function() {
				var scale = this.chart.scales.x;

				expect(scale.min).toEqual(+moment('2017', 'YYYY'));
				expect(scale.max).toEqual(+moment('2042', 'YYYY'));
				expect(getTicksLabels(scale)).toEqual([
					'2017', '2019', '2020', '2025', '2042']);
			});
			it ('should not add ticks for min and max if they extend the labels range', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.ticks.min = '2012';
				options.ticks.max = '2051';
				chart.update();

				expect(scale.min).toEqual(+moment('2012', 'YYYY'));
				expect(scale.max).toEqual(+moment('2051', 'YYYY'));
				expect(getTicksLabels(scale)).toEqual([
					'2017', '2019', '2020', '2025', '2042']);
			});
			it ('should not duplicate ticks if min and max are the labels limits', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.ticks.min = '2017';
				options.ticks.max = '2042';
				chart.update();

				expect(scale.min).toEqual(+moment('2017', 'YYYY'));
				expect(scale.max).toEqual(+moment('2042', 'YYYY'));
				expect(getTicksLabels(scale)).toEqual([
					'2017', '2019', '2020', '2025', '2042']);
			});
			it ('should correctly handle empty `data.labels` using "day" if `time.unit` is undefined`', function() {
				var chart = this.chart;
				var scale = chart.scales.x;

				chart.data.labels = [];
				chart.update();

				expect(scale.min).toEqual(+moment().startOf('day'));
				expect(scale.max).toEqual(+moment().endOf('day') + 1);
				expect(getTicksLabels(scale)).toEqual([]);
			});
			it ('should correctly handle empty `data.labels` using `time.unit`', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.time.unit = 'year';
				chart.data.labels = [];
				chart.update();

				expect(scale.min).toEqual(+moment().startOf('year'));
				expect(scale.max).toEqual(+moment().endOf('year') + 1);
				expect(getTicksLabels(scale)).toEqual([]);
			});
		});

		describe('is "data"', function() {
			beforeEach(function() {
				this.chart = window.acquireChart({
					type: 'line',
					data: {
						labels: ['2017', '2019', '2020', '2025', '2042'],
						datasets: [
							{data: [0, 1, 2, 3, 4, 5]},
							{data: [
								{t: '2018', y: 6},
								{t: '2020', y: 7},
								{t: '2043', y: 8}
							]}
						]
					},
					options: {
						scales: {
							xAxes: [{
								id: 'x',
								type: 'time',
								time: {
									parser: 'YYYY'
								},
								ticks: {
									source: 'data'
								}
							}]
						}
					}
				});
			});

			it ('should generate ticks from "datasets.data"', function() {
				var scale = this.chart.scales.x;

				expect(scale.min).toEqual(+moment('2017', 'YYYY'));
				expect(scale.max).toEqual(+moment('2043', 'YYYY'));
				expect(getTicksLabels(scale)).toEqual([
					'2017', '2018', '2019', '2020', '2025', '2042', '2043']);
			});
			it ('should not add ticks for min and max if they extend the labels range', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.ticks.min = '2012';
				options.ticks.max = '2051';
				chart.update();

				expect(scale.min).toEqual(+moment('2012', 'YYYY'));
				expect(scale.max).toEqual(+moment('2051', 'YYYY'));
				expect(getTicksLabels(scale)).toEqual([
					'2017', '2018', '2019', '2020', '2025', '2042', '2043']);
			});
			it ('should not duplicate ticks if min and max are the labels limits', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.ticks.min = '2017';
				options.ticks.max = '2043';
				chart.update();

				expect(scale.min).toEqual(+moment('2017', 'YYYY'));
				expect(scale.max).toEqual(+moment('2043', 'YYYY'));
				expect(getTicksLabels(scale)).toEqual([
					'2017', '2018', '2019', '2020', '2025', '2042', '2043']);
			});
			it ('should correctly handle empty `data.labels` using "day" if `time.unit` is undefined`', function() {
				var chart = this.chart;
				var scale = chart.scales.x;

				chart.data.labels = [];
				chart.update();

				expect(scale.min).toEqual(+moment('2018', 'YYYY'));
				expect(scale.max).toEqual(+moment('2043', 'YYYY'));
				expect(getTicksLabels(scale)).toEqual([
					'2018', '2020', '2043']);
			});
			it ('should correctly handle empty `data.labels` and hidden datasets using `time.unit`', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.time.unit = 'year';
				chart.data.labels = [];
				var meta = chart.getDatasetMeta(1);
				meta.hidden = true;
				chart.update();

				expect(scale.min).toEqual(+moment().startOf('year'));
				expect(scale.max).toEqual(+moment().endOf('year') + 1);
				expect(getTicksLabels(scale)).toEqual([]);
			});
		});
	});

	describe('when distribution', function() {
		describe('is "series"', function() {
			beforeEach(function() {
				this.chart = window.acquireChart({
					type: 'line',
					data: {
						labels: ['2017', '2019', '2020', '2025', '2042'],
						datasets: [{data: [0, 1, 2, 3, 4, 5]}]
					},
					options: {
						scales: {
							xAxes: [{
								id: 'x',
								type: 'time',
								time: {
									parser: 'YYYY'
								},
								distribution: 'series',
								ticks: {
									source: 'labels'
								}
							}],
							yAxes: [{
								display: false
							}]
						}
					}
				});
			});

			it ('should space data out with the same gap, whatever their time values', function() {
				var scale = this.chart.scales.x;
				var start = scale.left;
				var slice = scale.width / 4;

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(start);
				expect(scale.getPixelForValue('2019')).toBeCloseToPixel(start + slice);
				expect(scale.getPixelForValue('2020')).toBeCloseToPixel(start + slice * 2);
				expect(scale.getPixelForValue('2025')).toBeCloseToPixel(start + slice * 3);
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(start + slice * 4);
			});
			it ('should add a step before if scale.min is before the first data', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.ticks.min = '2012';
				chart.update();

				var start = scale.left;
				var slice = scale.width / 5;

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(start + slice);
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(start + slice * 5);
			});
			it ('should add a step after if scale.max is after the last data', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.ticks.max = '2050';
				chart.update();

				var start = scale.left;
				var slice = scale.width / 5;

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(start);
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(start + slice * 4);
			});
			it ('should add steps before and after if scale.min/max are outside the data range', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.ticks.min = '2012';
				options.ticks.max = '2050';
				chart.update();

				var start = scale.left;
				var slice = scale.width / 6;

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(start + slice);
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(start + slice * 5);
			});
		});
		describe('is "linear"', function() {
			beforeEach(function() {
				this.chart = window.acquireChart({
					type: 'line',
					data: {
						labels: ['2017', '2019', '2020', '2025', '2042'],
						datasets: [{data: [0, 1, 2, 3, 4, 5]}]
					},
					options: {
						scales: {
							xAxes: [{
								id: 'x',
								type: 'time',
								time: {
									parser: 'YYYY'
								},
								distribution: 'linear',
								ticks: {
									source: 'labels'
								}
							}],
							yAxes: [{
								display: false
							}]
						}
					}
				});
			});

			it ('should space data out with a gap relative to their time values', function() {
				var scale = this.chart.scales.x;
				var start = scale.left;
				var slice = scale.width / (2042 - 2017);

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(start);
				expect(scale.getPixelForValue('2019')).toBeCloseToPixel(start + slice * (2019 - 2017));
				expect(scale.getPixelForValue('2020')).toBeCloseToPixel(start + slice * (2020 - 2017));
				expect(scale.getPixelForValue('2025')).toBeCloseToPixel(start + slice * (2025 - 2017));
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(start + slice * (2042 - 2017));
			});
			it ('should take in account scale min and max if outside the ticks range', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.ticks.min = '2012';
				options.ticks.max = '2050';
				chart.update();

				var start = scale.left;
				var slice = scale.width / (2050 - 2012);

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(start + slice * (2017 - 2012));
				expect(scale.getPixelForValue('2019')).toBeCloseToPixel(start + slice * (2019 - 2012));
				expect(scale.getPixelForValue('2020')).toBeCloseToPixel(start + slice * (2020 - 2012));
				expect(scale.getPixelForValue('2025')).toBeCloseToPixel(start + slice * (2025 - 2012));
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(start + slice * (2042 - 2012));
			});
		});
	});

	describe('when bounds', function() {
		describe('is "data"', function() {
			it ('should preserve the data range', function() {
				var chart = window.acquireChart({
					type: 'line',
					data: {
						labels: ['02/20 08:00', '02/21 09:00', '02/22 10:00', '02/23 11:00'],
						datasets: [{data: [0, 1, 2, 3, 4, 5]}]
					},
					options: {
						scales: {
							xAxes: [{
								id: 'x',
								type: 'time',
								bounds: 'data',
								time: {
									parser: 'MM/DD HH:mm',
									unit: 'day'
								}
							}],
							yAxes: [{
								display: false
							}]
						}
					}
				});

				var scale = chart.scales.x;

				expect(scale.min).toEqual(+moment('02/20 08:00', 'MM/DD HH:mm'));
				expect(scale.max).toEqual(+moment('02/23 11:00', 'MM/DD HH:mm'));
				expect(scale.getPixelForValue('02/20 08:00')).toBeCloseToPixel(scale.left);
				expect(scale.getPixelForValue('02/23 11:00')).toBeCloseToPixel(scale.left + scale.width);
				expect(getTicksLabels(scale)).toEqual([
					'Feb 21', 'Feb 22', 'Feb 23']);
			});
		});

		describe('is "labels"', function() {
			it('should preserve the label range', function() {
				var chart = window.acquireChart({
					type: 'line',
					data: {
						labels: ['02/20 08:00', '02/21 09:00', '02/22 10:00', '02/23 11:00'],
						datasets: [{data: [0, 1, 2, 3, 4, 5]}]
					},
					options: {
						scales: {
							xAxes: [{
								id: 'x',
								type: 'time',
								bounds: 'ticks',
								time: {
									parser: 'MM/DD HH:mm',
									unit: 'day'
								}
							}],
							yAxes: [{
								display: false
							}]
						}
					}
				});

				var scale = chart.scales.x;
				var ticks = scale.getTicks();

				expect(scale.min).toEqual(ticks[0].value);
				expect(scale.max).toEqual(ticks[ticks.length - 1].value);
				expect(scale.getPixelForValue('02/20 08:00')).toBeCloseToPixel(60);
				expect(scale.getPixelForValue('02/23 11:00')).toBeCloseToPixel(426);
				expect(getTicksLabels(scale)).toEqual([
					'Feb 20', 'Feb 21', 'Feb 22', 'Feb 23', 'Feb 24']);
			});
		});
	});

	describe('when ticks.min and/or ticks.max are defined', function() {
		['auto', 'data', 'labels'].forEach(function(source) {
			['data', 'ticks'].forEach(function(bounds) {
				describe('and ticks.source is "' + source + '" and bounds "' + bounds + '"', function() {
					beforeEach(function() {
						this.chart = window.acquireChart({
							type: 'line',
							data: {
								labels: ['02/20 08:00', '02/21 09:00', '02/22 10:00', '02/23 11:00'],
								datasets: [{data: [0, 1, 2, 3, 4, 5]}]
							},
							options: {
								scales: {
									xAxes: [{
										id: 'x',
										type: 'time',
										bounds: bounds,
										time: {
											parser: 'MM/DD HH:mm',
											unit: 'day'
										},
										ticks: {
											source: source
										}
									}],
									yAxes: [{
										display: false
									}]
								}
							}
						});
					});

					it ('should expand scale to the min/max range', function() {
						var chart = this.chart;
						var scale = chart.scales.x;
						var options = chart.options.scales.xAxes[0];
						var min = '02/19 07:00';
						var max = '02/24 08:00';

						options.ticks.min = min;
						options.ticks.max = max;
						chart.update();

						expect(scale.min).toEqual(+moment(min, 'MM/DD HH:mm'));
						expect(scale.max).toEqual(+moment(max, 'MM/DD HH:mm'));
						expect(scale.getPixelForValue(min)).toBeCloseToPixel(scale.left);
						expect(scale.getPixelForValue(max)).toBeCloseToPixel(scale.left + scale.width);
						scale.getTicks().forEach(function(tick) {
							expect(tick.value >= +moment(min, 'MM/DD HH:mm')).toBeTruthy();
							expect(tick.value <= +moment(max, 'MM/DD HH:mm')).toBeTruthy();
						});
					});
					it ('should shrink scale to the min/max range', function() {
						var chart = this.chart;
						var scale = chart.scales.x;
						var options = chart.options.scales.xAxes[0];
						var min = '02/21 07:00';
						var max = '02/22 20:00';

						options.ticks.min = min;
						options.ticks.max = max;
						chart.update();

						expect(scale.min).toEqual(+moment(min, 'MM/DD HH:mm'));
						expect(scale.max).toEqual(+moment(max, 'MM/DD HH:mm'));
						expect(scale.getPixelForValue(min)).toBeCloseToPixel(scale.left);
						expect(scale.getPixelForValue(max)).toBeCloseToPixel(scale.left + scale.width);
						scale.getTicks().forEach(function(tick) {
							expect(tick.value >= +moment(min, 'MM/DD HH:mm')).toBeTruthy();
							expect(tick.value <= +moment(max, 'MM/DD HH:mm')).toBeTruthy();
						});
					});
				});
			});
		});
	});

	['auto', 'data', 'labels'].forEach(function(source) {
		['series', 'linear'].forEach(function(distribution) {
			describe('when ticks.source is "' + source + '" and distribution is "' + distribution + '"', function() {
				beforeEach(function() {
					this.chart = window.acquireChart({
						type: 'line',
						data: {
							labels: ['2017', '2019', '2020', '2025', '2042'],
							datasets: [{data: [0, 1, 2, 3, 4, 5]}]
						},
						options: {
							scales: {
								xAxes: [{
									id: 'x',
									type: 'time',
									time: {
										parser: 'YYYY'
									},
									ticks: {
										source: source
									},
									distribution: distribution
								}]
							}
						}
					});
				});

				it ('should not add offset from the edges', function() {
					var scale = this.chart.scales.x;

					expect(scale.getPixelForValue('2017')).toBeCloseToPixel(scale.left);
					expect(scale.getPixelForValue('2042')).toBeCloseToPixel(scale.left + scale.width);
				});

				it ('should add offset from the edges if offset is true', function() {
					var chart = this.chart;
					var scale = chart.scales.x;
					var options = chart.options.scales.xAxes[0];

					options.offset = true;
					chart.update();

					var numTicks = scale.ticks.length;
					var firstTickInterval = scale.getPixelForTick(1) - scale.getPixelForTick(0);
					var lastTickInterval = scale.getPixelForTick(numTicks - 1) - scale.getPixelForTick(numTicks - 2);

					expect(scale.getPixelForValue('2017')).toBeCloseToPixel(scale.left + firstTickInterval / 2);
					expect(scale.getPixelForValue('2042')).toBeCloseToPixel(scale.left + scale.width - lastTickInterval / 2);
				});

				it ('should not add offset if min and max extend the labels range', function() {
					var chart = this.chart;
					var scale = chart.scales.x;
					var options = chart.options.scales.xAxes[0];

					options.ticks.min = '2012';
					options.ticks.max = '2051';
					chart.update();

					expect(scale.getPixelForValue('2012')).toBeCloseToPixel(scale.left);
					expect(scale.getPixelForValue('2051')).toBeCloseToPixel(scale.left + scale.width);
				});

				it ('should add offset if min and max extend the labels range and offset is true', function() {
					var chart = this.chart;
					var scale = chart.scales.x;
					var options = chart.options.scales.xAxes[0];

					options.ticks.min = '2012';
					options.ticks.max = '2051';
					options.offset = true;
					chart.update();

					var numTicks = scale.ticks.length;
					var firstTickInterval = scale.getPixelForTick(1) - scale.getPixelForTick(0);
					var lastTickInterval = scale.getPixelForTick(numTicks - 1) - scale.getPixelForTick(numTicks - 2);
					expect(scale.getPixelForValue('2012')).toBeCloseToPixel(scale.left + firstTickInterval / 2);
					expect(scale.getPixelForValue('2051')).toBeCloseToPixel(scale.left + scale.width - lastTickInterval / 2);
				});
			});
		});
	});

	describe('when ticks.reverse', function() {
		describe('is "true"', function() {
			beforeEach(function() {
				this.chart = window.acquireChart({
					type: 'line',
					data: {
						labels: ['2017', '2019', '2020', '2025', '2042'],
						datasets: [{data: [0, 1, 2, 3, 4, 5]}]
					},
					options: {
						scales: {
							xAxes: [{
								id: 'x',
								type: 'time',
								time: {
									parser: 'YYYY',
								},
								ticks: {
									source: 'labels',
									reverse: true
								}
							}],
							yAxes: [{
								display: false
							}]
						}
					}
				});
			});

			it ('should reverse the labels', function() {
				var scale = this.chart.scales.x;
				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(scale.left + scale.width);
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(scale.left);
			});

			it ('should reverse the values for pixels', function() {
				var scale = this.chart.chart.scales.x;
				expect(scale.getValueForPixel(scale.left)).toBeCloseToTime({
					value: moment('2042-01-01T00:00:00'),
					unit: 'hour',
				});
				expect(scale.getValueForPixel(scale.left + scale.width)).toBeCloseToTime({
					value: moment('2017-01-01T00:00:00'),
					unit: 'hour',
				});
			});

			it ('should reverse the bars and add offsets if offset is true', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.offset = true;
				chart.update();

				var numTicks = scale.ticks.length;
				var firstTickInterval = scale.getPixelForTick(1) - scale.getPixelForTick(0);
				var lastTickInterval = scale.getPixelForTick(numTicks - 1) - scale.getPixelForTick(numTicks - 2);

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(scale.left + scale.width - lastTickInterval / 2);
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(scale.left + firstTickInterval / 2);
			});

			it ('should reverse the values for pixels if offset is true', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.offset = true;
				chart.update();

				var numTicks = scale.ticks.length;
				var firstTickInterval = scale.getPixelForTick(1) - scale.getPixelForTick(0);
				var lastTickInterval = scale.getPixelForTick(numTicks - 1) - scale.getPixelForTick(numTicks - 2);

				expect(scale.getValueForPixel(scale.left + firstTickInterval / 2)).toBeCloseToTime({
					value: moment('2042-01-01T00:00:00'),
					unit: 'hour',
				});
				expect(scale.getValueForPixel(scale.left + scale.width - lastTickInterval / 2)).toBeCloseToTime({
					value: moment('2017-01-01T00:00:00'),
					unit: 'hour',
				});
			});
		});
	});

	describe('when ticks.reverse is "true" and distribution', function() {
		describe('is "series"', function() {
			beforeEach(function() {
				this.chart = window.acquireChart({
					type: 'line',
					data: {
						labels: ['2017', '2019', '2020', '2025', '2042'],
						datasets: [{data: [0, 1, 2, 3, 4, 5]}]
					},
					options: {
						scales: {
							xAxes: [{
								id: 'x',
								type: 'time',
								time: {
									parser: 'YYYY'
								},
								distribution: 'series',
								ticks: {
									source: 'labels',
									reverse: true
								}
							}],
							yAxes: [{
								display: false
							}]
						}
					}
				});
			});

			it ('should reverse the labels and space data out with the same gap, whatever their time values', function() {
				var scale = this.chart.scales.x;
				var start = scale.left;
				var slice = scale.width / 4;

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(start + slice * 4);
				expect(scale.getPixelForValue('2019')).toBeCloseToPixel(start + slice * 3);
				expect(scale.getPixelForValue('2020')).toBeCloseToPixel(start + slice * 2);
				expect(scale.getPixelForValue('2025')).toBeCloseToPixel(start + slice);
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(start);
			});

			it ('should reverse the labels and should add a step before if scale.min is before the first data', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.ticks.min = '2012';
				chart.update();

				var start = scale.left;
				var slice = scale.width / 5;

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(start + slice * 4);
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(start);
			});

			it ('should reverse the labels and should add a step after if scale.max is after the last data', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.ticks.max = '2050';
				chart.update();

				var start = scale.left;
				var slice = scale.width / 5;

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(start + slice * 5);
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(start + slice);
			});

			it ('should reverse the labels and should add steps before and after if scale.min/max are outside the data range', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.ticks.min = '2012';
				options.ticks.max = '2050';
				chart.update();

				var start = scale.left;
				var slice = scale.width / 6;

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(start + slice * 5);
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(start + slice);
			});
		});
		describe('is "linear"', function() {
			beforeEach(function() {
				this.chart = window.acquireChart({
					type: 'line',
					data: {
						labels: ['2017', '2019', '2020', '2025', '2042'],
						datasets: [{data: [0, 1, 2, 3, 4, 5]}]
					},
					options: {
						scales: {
							xAxes: [{
								id: 'x',
								type: 'time',
								time: {
									parser: 'YYYY'
								},
								distribution: 'linear',
								ticks: {
									source: 'labels',
									reverse: true
								}
							}],
							yAxes: [{
								display: false
							}]
						}
					}
				});
			});

			it ('should reverse the labels and should space data out with a gap relative to their time values', function() {
				var scale = this.chart.scales.x;
				var start = scale.left;
				var slice = scale.width / (2042 - 2017);

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(start + slice * (2042 - 2017));
				expect(scale.getPixelForValue('2019')).toBeCloseToPixel(start + slice * (2042 - 2019));
				expect(scale.getPixelForValue('2020')).toBeCloseToPixel(start + slice * (2042 - 2020));
				expect(scale.getPixelForValue('2025')).toBeCloseToPixel(start + slice * (2042 - 2025));
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(start);
			});

			it ('should reverse the labels and should take in account scale min and max if outside the ticks range', function() {
				var chart = this.chart;
				var scale = chart.scales.x;
				var options = chart.options.scales.xAxes[0];

				options.ticks.min = '2012';
				options.ticks.max = '2050';
				chart.update();

				var start = scale.left;
				var slice = scale.width / (2050 - 2012);

				expect(scale.getPixelForValue('2017')).toBeCloseToPixel(start + slice * (2050 - 2017));
				expect(scale.getPixelForValue('2019')).toBeCloseToPixel(start + slice * (2050 - 2019));
				expect(scale.getPixelForValue('2020')).toBeCloseToPixel(start + slice * (2050 - 2020));
				expect(scale.getPixelForValue('2025')).toBeCloseToPixel(start + slice * (2050 - 2025));
				expect(scale.getPixelForValue('2042')).toBeCloseToPixel(start + slice * (2050 - 2042));
			});
		});
	});

	describe('labels', function() {
		it('should read labels from scale / xLabels / yLabels', function() {
			var timeOpts = {
				parser: 'YYYY',
				unit: 'year',
				displayFormats: {
					year: 'YYYY'
				}
			};
			var chart = window.acquireChart({
				type: 'line',
				data: {
					labels: ['1975', '1976', '1977'],
					xLabels: ['1985', '1986', '1987'],
					yLabels: ['1995', '1996', '1997']
				},
				options: {
					scales: {
						xAxes: [{
							id: 'x',
							type: 'time',
							labels: ['2015', '2016', '2017'],
							time: timeOpts
						},
						{
							id: 'x2',
							type: 'time',
							time: timeOpts
						}],
						yAxes: [{
							id: 'y',
							type: 'time',
							time: timeOpts
						},
						{
							id: 'y2',
							type: 'time',
							labels: ['2005', '2006', '2007'],
							time: timeOpts
						}]
					}
				}
			});

			expect(getTicksLabels(chart.scales.x)).toEqual(['2015', '2016', '2017']);
			expect(getTicksLabels(chart.scales.x2)).toEqual(['1985', '1986', '1987']);
			expect(getTicksLabels(chart.scales.y)).toEqual(['1995', '1996', '1997']);
			expect(getTicksLabels(chart.scales.y2)).toEqual(['2005', '2006', '2007']);
		});
	});

	describe('Deprecations', function() {
		describe('options.time.displayFormats', function() {
			it('should generate defaults from adapter presets', function() {
				var chart = window.acquireChart({
					type: 'line',
					data: {},
					options: {
						scales: {
							xAxes: [{
								id: 'x',
								type: 'time'
							}]
						}
					}
				});

				// NOTE: built-in adapter uses moment
				var expected = {
					datetime: 'MMM D, YYYY, h:mm:ss a',
					millisecond: 'h:mm:ss.SSS a',
					second: 'h:mm:ss a',
					minute: 'h:mm a',
					hour: 'hA',
					day: 'MMM D',
					week: 'll',
					month: 'MMM YYYY',
					quarter: '[Q]Q - YYYY',
					year: 'YYYY'
				};

				expect(chart.scales.x.options.time.displayFormats).toEqual(expected);
				expect(chart.options.scales.xAxes[0].time.displayFormats).toEqual(expected);
			});

			it('should merge user formats with adapter presets', function() {
				var chart = window.acquireChart({
					type: 'line',
					data: {},
					options: {
						scales: {
							xAxes: [{
								id: 'x',
								type: 'time',
								time: {
									displayFormats: {
										millisecond: 'foo',
										hour: 'bar',
										month: 'bla'
									}
								}
							}]
						}
					}
				});

				// NOTE: built-in adapter uses moment
				var expected = {
					datetime: 'MMM D, YYYY, h:mm:ss a',
					millisecond: 'foo',
					second: 'h:mm:ss a',
					minute: 'h:mm a',
					hour: 'bar',
					day: 'MMM D',
					week: 'll',
					month: 'bla',
					quarter: '[Q]Q - YYYY',
					year: 'YYYY'
				};

				expect(chart.scales.x.options.time.displayFormats).toEqual(expected);
				expect(chart.options.scales.xAxes[0].time.displayFormats).toEqual(expected);
			});
		});
	});
});