Add util methods for CA duration chart

The methods added in this commit are used for computing the
data which is used for the cycle analytics duration chart.

app/assets/javascripts/lib/utils/datetime_utility.js

@@ -602,3 +602,19 @@ export const getDatesInRange = (d1, d2, formatter = x => x) => {
  * @return {Number} number of milliseconds
  */
 export const secondsToMilliseconds = seconds => seconds * 1000;
+
+/**
+ * Converts the supplied number of seconds to days.
+ *
+ * @param {Number} seconds
+ * @return {Number} number of days
+ */
+export const secondsToDays = seconds => Math.round(seconds / 86400);
+
+/**
+ * Returns the date after the date provided
+ *
+ * @param {Date} date the initial date
+ * @return {Date} the date following the date provided
+ */
+export const dayAfter = date => new Date(newDate(date).setDate(date.getDate() + 1));

ee/app/assets/javascripts/analytics/cycle_analytics/utils.js

 import { convertObjectPropsToCamelCase } from '~/lib/utils/common_utils';
 import { convertToSnakeCase } from '~/lib/utils/text_utility';
+import { newDate, dayAfter, secondsToDays } from '~/lib/utils/datetime_utility';
 import { isString } from 'underscore';
+import dateFormat from 'dateformat';
+import { dateFormats } from '../shared/constants';
 
 const EVENT_TYPE_LABEL = 'label';
 
@@ -45,3 +48,108 @@ export const nestQueryStringKeys = (obj = null, targetKey = '') => {
     return { ...prev, [customKey]: value };
   }, {});
 };
+
+/**
+ * Takes the duration data for selected stages, transforms the date values and returns
+ * the data in a flattened array
+ *
+ * The received data is expected to be the following format; One top level object in the array per stage,
+ * each potentially having multiple data entries.
+ * [
+ *   {
+ *    slug: 'issue',
+ *    selected: true,
+ *    data: [
+ *      {
+ *        'duration_in_seconds': 1234,
+ *        'finished_at': '2019-09-02T18:25:43.511Z'
+ *      },
+ *      ...
+ *    ]
+ *   },
+ *   ...
+ * ]
+ *
+ * The data is then transformed and flattened into the following format;
+ * [
+ *  {
+ *    'duration_in_seconds': 1234,
+ *    'finished_at': '2019-09-02'
+ *  },
+ *  ...
+ * ]
+ *
+ * @param {Array} data - The duration data for selected stages
+ * @returns {Array} An array with each item being an object containing the duration_in_seconds and finished_at values for an event
+ */
+export const flattenDurationChartData = data =>
+  data
+    .map(stage =>
+      stage.data.map(event => {
+        const date = new Date(event.finished_at);
+        return {
+          ...event,
+          finished_at: dateFormat(date, dateFormats.isoDate),
+        };
+      }),
+    )
+    .flat();
+
+/**
+ * Takes the duration data for selected stages, groups the data by day and calculates the total duration
+ * per day.
+ *
+ * The received data is expected to be the following format; One top level object in the array per stage,
+ * each potentially having multiple data entries.
+ * [
+ *   {
+ *    slug: 'issue',
+ *    selected: true,
+ *    data: [
+ *      {
+ *        'duration_in_seconds': 1234,
+ *        'finished_at': '2019-09-02T18:25:43.511Z'
+ *      },
+ *      ...
+ *    ]
+ *   },
+ *   ...
+ * ]
+ *
+ * The data is then computed and transformed into a format that can be passed to the chart:
+ * [
+ *  ['2019-09-02', 7, '2019-09-02'],
+ *  ['2019-09-03', 10, '2019-09-03'],
+ *  ['2019-09-04', 8, '2019-09-04'],
+ *  ...
+ * ]
+ *
+ * In the data above, each array i represents a point in the scatterplot with the following data:
+ * i[0] = date, displayed on x axis
+ * i[1] = metric, displayed on y axis
+ * i[2] = date, used in the tooltip
+ *
+ * @param {Array} data - The duration data for selected stages
+ * @param {Date} startDate - The globally selected cycle analytics start date
+ * @param {Date} endDate - The globally selected cycle analytics stendart date
+ * @returns {Array} An array with each item being another arry of three items (plottable date, computed total, tooltip display date)
+ */
+export const getDurationChartData = (data, startDate, endDate) => {
+  const flattenedData = flattenDurationChartData(data);
+  const eventData = [];
+
+  for (
+    let currentDate = newDate(startDate);
+    currentDate <= endDate;
+    currentDate = dayAfter(currentDate)
+  ) {
+    const currentISODate = dateFormat(newDate(currentDate), dateFormats.isoDate);
+    const valuesForDay = flattenedData.filter(object => object.finished_at === currentISODate);
+    const summedData = valuesForDay.reduce((total, value) => total + value.duration_in_seconds, 0);
+    const summedDataInDays = secondsToDays(summedData);
+
+    if (summedDataInDays) eventData.push([currentISODate, summedDataInDays, currentISODate]);
+  }
+
+  return eventData;
+};

ee/spec/frontend/analytics/cycle_analytics/mock_data.js

@@ -55,7 +55,8 @@ export const rawEvents = rawIssueEvents.events;
 
 const deepCamelCase = obj => convertObjectPropsToCamelCase(obj, { deep: true });
 
-const defaultStages = ['issue', 'plan', 'review', 'code', 'test', 'staging', 'production'];
+export const defaultStages = ['issue', 'plan', 'review', 'code', 'test', 'staging', 'production'];
+
 const stageFixtures = defaultStages.reduce((acc, stage) => {
   const { events } = getJSONFixture(endpoints.stageEvents(stage));
   return {
@@ -105,3 +106,39 @@ export const customStageEvents = [
 ];
 
 export const tasksByTypeData = getJSONFixture('analytics/type_of_work/tasks_by_type.json');
+
+export const rawDurationData = [
+  {
+    duration_in_seconds: 1234000,
+    finished_at: '2019-01-01T00:00:00.000Z',
+  },
+  {
+    duration_in_seconds: 4321000,
+    finished_at: '2019-01-02T00:00:00.000Z',
+  },
+];
+
+export const transformedDurationData = [
+  {
+    slug: 'issue',
+    selected: true,
+    data: rawDurationData,
+  },
+  {
+    slug: 'plan',
+    selected: true,
+    data: rawDurationData,
+  },
+];
+
+export const flattenedDurationData = [
+  { duration_in_seconds: 1234000, finished_at: '2019-01-01' },
+  { duration_in_seconds: 4321000, finished_at: '2019-01-02' },
+  { duration_in_seconds: 1234000, finished_at: '2019-01-01' },
+  { duration_in_seconds: 4321000, finished_at: '2019-01-02' },
+];
+
+export const durationChartPlottableData = [
+  ['2019-01-01', 29, '2019-01-01'],
+  ['2019-01-02', 100, '2019-01-02'],
+];

ee/spec/frontend/analytics/cycle_analytics/utils_spec.js

@@ -6,12 +6,19 @@ import {
   eventsByIdentifier,
   getLabelEventsIdentifiers,
   nestQueryStringKeys,
+  flattenDurationChartData,
+  getDurationChartData,
 } from 'ee/analytics/cycle_analytics/utils';
 import {
   customStageEvents as events,
   labelStartEvent,
   labelStopEvent,
   customStageStartEvents as startEvents,
+  transformedDurationData,
+  flattenedDurationData,
+  durationChartPlottableData,
+  startDate,
+  endDate,
 } from './mock_data';
 
 const labelEvents = [labelStartEvent, labelStopEvent].map(i => i.identifier);
@@ -130,4 +137,20 @@ describe('Cycle analytics utils', () => {
       });
     });
   });
+
+  describe('flattenDurationChartData', () => {
+    it('flattens the data as expected', () => {
+      const flattenedData = flattenDurationChartData(transformedDurationData);
+
+      expect(flattenedData).toStrictEqual(flattenedDurationData);
+    });
+  });
+
+  describe('cycleAnalyticsDurationChart', () => {
+    it('computes the plottable data as expected', () => {
+      const plottableData = getDurationChartData(transformedDurationData, startDate, endDate);
+
+      expect(plottableData).toStrictEqual(durationChartPlottableData);
+    });
+  });
 });

spec/frontend/lib/utils/datetime_utility_spec.js

@@ -482,3 +482,27 @@ describe('secondsToMilliseconds', () => {
     expect(datetimeUtility.secondsToMilliseconds(123)).toBe(123000);
   });
 });
+
+describe('dayAfter', () => {
+  const date = new Date('2019-07-16T00:00:00.000Z');
+
+  it('returns the following date', () => {
+    const nextDay = datetimeUtility.dayAfter(date);
+    const expectedNextDate = new Date('2019-07-17T00:00:00.000Z');
+
+    expect(nextDay).toStrictEqual(expectedNextDate);
+  });
+
+  it('does not modifiy the original date', () => {
+    datetimeUtility.dayAfter(date);
+    expect(date).toStrictEqual(new Date('2019-07-16T00:00:00.000Z'));
+  });
+});
+
+describe('secondsToDays', () => {
+  it('converts seconds to days correctly', () => {
+    expect(datetimeUtility.secondsToDays(0)).toBe(0);
+    expect(datetimeUtility.secondsToDays(90000)).toBe(1);
+    expect(datetimeUtility.secondsToDays(270000)).toBe(3);
+  });
+});