From 71aac6968165c874dd918ca0ec3c23ae6071ddc9 Mon Sep 17 00:00:00 2001
From: Ben McCann <322311+benmccann@users.noreply.github.com>
Date: Sun, 20 Oct 2019 20:04:37 -0700
Subject: [PATCH] Fix unit determination when autoSkip is enabled

---
 src/scales/scale.time.js       | 19 ++++++++++++-------
 test/specs/scale.time.tests.js |  8 ++++----
 2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/src/scales/scale.time.js b/src/scales/scale.time.js
index 38428c8ffd7..83bf4e496e5 100644
--- a/src/scales/scale.time.js
+++ b/src/scales/scale.time.js
@@ -257,7 +257,7 @@ function determineUnitForAutoTicks(minUnit, min, max, capacity) {
 
 	for (i = UNITS.indexOf(minUnit); i < ilen - 1; ++i) {
 		interval = INTERVALS[UNITS[i]];
-		factor = interval.steps ? interval.steps / 2 : MAX_INTEGER;
+		factor = interval.steps ? interval.steps : MAX_INTEGER;
 
 		if (interval.common && Math.ceil((max - min) / (factor * interval.size)) <= capacity) {
 			return UNITS[i];
@@ -270,12 +270,12 @@ function determineUnitForAutoTicks(minUnit, min, max, capacity) {
 /**
  * Figures out what unit to format a set of ticks with
  */
-function determineUnitForFormatting(scale, ticks, minUnit, min, max) {
+function determineUnitForFormatting(scale, numTicks, minUnit, min, max) {
 	var i, unit;
 
 	for (i = UNITS.length - 1; i >= UNITS.indexOf(minUnit); i--) {
 		unit = UNITS[i];
-		if (INTERVALS[unit].common && scale._adapter.diff(max, min, unit) >= ticks.length - 1) {
+		if (INTERVALS[unit].common && scale._adapter.diff(max, min, unit) >= numTicks - 1) {
 			return unit;
 		}
 	}
@@ -562,11 +562,12 @@ module.exports = Scale.extend({
 		var min = me.min;
 		var max = me.max;
 		var options = me.options;
+		var tickOpts = options.ticks;
 		var timeOpts = options.time;
 		var timestamps = me._timestamps;
 		var ticks = [];
 		var capacity = me.getLabelCapacity(min);
-		var source = options.ticks.source;
+		var source = tickOpts.source;
 		var distribution = options.distribution;
 		var i, ilen, timestamp;
 
@@ -599,13 +600,17 @@ module.exports = Scale.extend({
 		me.max = max;
 
 		// PRIVATE
-		me._unit = timeOpts.unit || determineUnitForFormatting(me, ticks, timeOpts.minUnit, me.min, me.max);
-		me._majorUnit = !options.ticks.major.enabled || me._unit === 'year' ? undefined
+		// determineUnitForFormatting relies on the number of ticks so we don't use it when
+		// autoSkip is enabled because we don't yet know what the final number of ticks will be
+		me._unit = timeOpts.unit || (tickOpts.autoSkip
+			? determineUnitForAutoTicks(timeOpts.minUnit, me.min, me.max, capacity)
+			: determineUnitForFormatting(me, ticks.length, timeOpts.minUnit, me.min, me.max));
+		me._majorUnit = !tickOpts.major.enabled || me._unit === 'year' ? undefined
 			: determineMajorUnit(me._unit);
 		me._table = buildLookupTable(me._timestamps.data, min, max, distribution);
 		me._offsets = computeOffsets(me._table, ticks, min, max, options);
 
-		if (options.ticks.reverse) {
+		if (tickOpts.reverse) {
 			ticks.reverse();
 		}
 
diff --git a/test/specs/scale.time.tests.js b/test/specs/scale.time.tests.js
index 593a846b0f9..71967491d4c 100755
--- a/test/specs/scale.time.tests.js
+++ b/test/specs/scale.time.tests.js
@@ -128,7 +128,7 @@ describe('Time scale tests', function() {
 			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']);
+			expect(ticks.length).toEqual(217);
 		});
 
 		it('should accept labels as date objects', function() {
@@ -139,7 +139,7 @@ describe('Time scale tests', function() {
 			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']);
+			expect(ticks.length).toEqual(217);
 		});
 
 		it('should accept data as xy points', function() {
@@ -187,7 +187,7 @@ describe('Time scale tests', function() {
 			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']);
+			expect(ticks.length).toEqual(217);
 		});
 
 		it('should accept data as ty points', function() {
@@ -235,7 +235,7 @@ describe('Time scale tests', function() {
 			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']);
+			expect(ticks.length).toEqual(217);
 		});
 	});