fix(axes): correctly remove only consecutive duplicated ticks

integration/tests/axis_stories.test.ts

@@ -65,4 +65,9 @@ describe('Axis stories', () => {
       'http://localhost:9001/?path=/story/axes--custom-mixed&knob-left min=2&knob-xDomain max=2',
     );
   });
+  it('should hide consecutive duplicate ticks', async() => {
+    await common.expectChartAtUrlToMatchScreenshot(
+      'http://localhost:9001/?path=/story/axes--duplicate-ticks&knob-formatter=hourly&knob-Show duplicate ticks in x axis=true',
+    );
+  });
 });

src/chart_types/xy_chart/utils/axis_utils.test.ts

@@ -55,7 +55,7 @@ import {
   enableDuplicatedTicks,
 } from './axis_utils';
 import { computeXScale } from './scales';
-import { AxisSpec, DomainRange, AxisStyle, DEFAULT_GLOBAL_ID } from './specs';
+import { AxisSpec, DomainRange, AxisStyle, DEFAULT_GLOBAL_ID, TickFormatter } from './specs';
 
 describe('Axis computational utils', () => {
   const mockedRect = {
@@ -1435,6 +1435,49 @@ describe('Axis computational utils', () => {
       { value: 1547596800000, label: '2019-01-16', position: 568.2958333333333 },
     ]);
   });
+  test('should show unique consecutive ticks if duplicateTicks is set to false', () => {
+    const formatter: TickFormatter = (d, options = { timeZone: 'utc+1' }) => DateTime.fromMillis(d, { setZone: true, zone: options.timeZone }).toFormat('HH:mm');
+    const axisSpec: AxisSpec = {
+      id: 'bottom',
+      position: 'bottom',
+      showDuplicatedTicks: false,
+      chartType: 'xy_axis',
+      specType: 'axis',
+      groupId: DEFAULT_GLOBAL_ID,
+      hide: false,
+      showOverlappingLabels: false,
+      showOverlappingTicks: false,
+      tickSize: 10,
+      tickPadding: 10,
+      tickLabelRotation: 0,
+      tickFormat: formatter,
+    };
+    const xDomainTime: XDomain = {
+      type: 'xDomain',
+      isBandScale: false,
+      timeZone: 'utc+1',
+      domain: [1547190000000, 1547622000000],
+      minInterval: 86400000,
+      scaleType: ScaleType.Time,
+    };
+    const scale: Scale = computeXScale({ xDomain: xDomainTime, totalBarsInCluster: 0, range: [0, 603.5] });
+    const offset = 0;
+    const tickFormatOption = { timeZone: xDomainTime.timeZone };
+    const ticks = enableDuplicatedTicks(axisSpec, scale, offset, tickFormatOption);
+    const tickLabels = ticks.map(({ label }) => ({ label }));
+    expect(tickLabels).toEqual([
+      { label: '12:00' },
+      { label: '00:00' },
+      { label: '12:00' },
+      { label: '00:00' },
+      { label: '12:00' },
+      { label: '00:00' },
+      { label: '12:00' },
+      { label: '00:00' },
+      { label: '12:00' },
+      { label: '00:00' },
+    ]);
+  });
   test('should show duplicate tick labels if duplicateTicks is set to true', () => {
     const now = DateTime.fromISO('2019-01-11T00:00:00.000')
       .setZone('utc+1')

src/chart_types/xy_chart/utils/axis_utils.ts

@@ -471,7 +471,7 @@ export function enableDuplicatedTicks(
   if (axisSpec.showDuplicatedTicks === true) {
     return allTicks;
   }
-  return getUniqueValues(allTicks, 'label');
+  return getUniqueValues(allTicks, 'label', true);
 }
 
 /** @internal */

src/utils/commons.ts

@@ -331,7 +331,7 @@ export function mergePartial<T>(
 }
 
 /** @internal */
-export function getUniqueValues<T>(fullArray: T[], uniqueProperty: keyof T): T[] {
+export function getUniqueValues<T>(fullArray: T[], uniqueProperty: keyof T, filterConsecutives = false): T[] {
   return fullArray.reduce<{
     filtered: T[];
     uniqueValues: Set<T[keyof T]>;
@@ -341,7 +341,12 @@ export function getUniqueValues<T>(fullArray: T[], uniqueProperty: keyof T): T[]
       if (acc.uniqueValues.has(uniqueValue)) {
         return acc;
       }
-      acc.uniqueValues.add(uniqueValue);
+      if (filterConsecutives) {
+        acc.uniqueValues.clear();
+        acc.uniqueValues.add(uniqueValue);
+      } else {
+        acc.uniqueValues.add(uniqueValue);
+      }
       acc.filtered.push(currentValue);
       return acc;
     },

stories/axes/12_duplicate_ticks.tsx

@@ -17,12 +17,12 @@
  * under the License.
  */
 
-import { boolean } from '@storybook/addon-knobs';
+import { boolean, select } from '@storybook/addon-knobs';
 import { DateTime } from 'luxon';
 import moment from 'moment-timezone';
 import React from 'react';
 
-import { Axis, Chart, LineSeries, Position, ScaleType, niceTimeFormatter } from '../../src';
+import { Axis, Chart, LineSeries, Position, ScaleType, niceTimeFormatter, TickFormatter } from '../../src';
 import { KIBANA_METRICS } from '../../src/utils/data_samples/test_dataset_kibana';
 
 export const Example = () => {
@@ -31,11 +31,16 @@ export const Example = () => {
     .toMillis();
   const oneDay = moment.duration(1, 'd');
   const twoDays = moment.duration(2, 'd');
-  const oneMonth = moment.duration(31, 'd');
   const threeDays = moment.duration(3, 'd');
   const fourDays = moment.duration(4, 'd');
   const fiveDays = moment.duration(5, 'd');
-  const formatter = niceTimeFormatter([now, oneMonth.add(now).asMilliseconds()]);
+  const formatters: Record<string, TickFormatter> = {
+    daily: niceTimeFormatter([now, moment.duration(31, 'd').add(now).asMilliseconds()]),
+    hourly: (d) => moment(d).format('HH:mm'),
+  };
+  const formatterSelect = select<string>('formatter', ['daily', 'hourly'], 'daily');
+  const formatter = formatters[formatterSelect];
+
   const duplicateTicksInAxis = boolean('Show duplicate ticks in x axis', false);
   return (
     <Chart className="story-chart">