[data.search.aggs]: Clean up TimeBuckets implementation (#62123)

* Created tests for time_buckets. Clean up code. Removed getConfig method.

* Fixed comments

* Fixed comments (2)

* Fixes

* Removed __cached__

* Fixes for comments

* some refactoring

* Fixed comment about config

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

src/plugins/data/public/search/aggs/buckets/date_histogram.ts

@@ -44,28 +44,23 @@ const updateTimeBuckets = (
   timefilter: TimefilterContract,
   customBuckets?: IBucketDateHistogramAggConfig['buckets']
 ) => {
-  const bounds = agg.params.timeRange ? timefilter.calculateBounds(agg.params.timeRange) : null;
+  const bounds =
+    agg.params.timeRange && agg.fieldIsTimeField()
+      ? timefilter.calculateBounds(agg.params.timeRange)
+      : undefined;
   const buckets = customBuckets || agg.buckets;
-  buckets.setBounds(agg.fieldIsTimeField() && bounds);
+  buckets.setBounds(bounds);
   buckets.setInterval(agg.params.interval);
 };
 
-// TODO: Need to incorporate these properly into TimeBuckets
-interface ITimeBuckets {
-  setBounds: Function;
-  getScaledDateFormat: TimeBuckets['getScaledDateFormat'];
-  setInterval: Function;
-  getInterval: Function;
-}
-
 export interface DateHistogramBucketAggDependencies {
   uiSettings: IUiSettingsClient;
   query: QuerySetup;
   getInternalStartServices: GetInternalStartServicesFn;
 }
 
 export interface IBucketDateHistogramAggConfig extends IBucketAggConfig {
-  buckets: ITimeBuckets;
+  buckets: TimeBuckets;
 }
 
 export function isDateHistogramBucketAggConfig(agg: any): agg is IBucketDateHistogramAggConfig {
@@ -113,7 +108,12 @@ export const getDateHistogramBucketAgg = ({
               if (buckets) return buckets;
 
               const { timefilter } = query.timefilter;
-              buckets = new TimeBuckets({ uiSettings });
+              buckets = new TimeBuckets({
+                'histogram:maxBars': uiSettings.get('histogram:maxBars'),
+                'histogram:barTarget': uiSettings.get('histogram:barTarget'),
+                dateFormat: uiSettings.get('dateFormat'),
+                'dateFormat:scaled': uiSettings.get('dateFormat:scaled'),
+              });
               updateTimeBuckets(this, timefilter, buckets);
 
               return buckets;
@@ -206,7 +206,8 @@ export const getDateHistogramBucketAgg = ({
               ...dateHistogramInterval(interval.expression),
             };
 
-            const scaleMetrics = scaleMetricValues && interval.scaled && interval.scale < 1;
+            const scaleMetrics =
+              scaleMetricValues && interval.scaled && interval.scale && interval.scale < 1;
             if (scaleMetrics && aggs) {
               const metrics = aggs.aggs.filter(a => isMetricAggType(a.type));
               const all = every(metrics, (a: IBucketAggConfig) => {
@@ -218,7 +219,7 @@ export const getDateHistogramBucketAgg = ({
               });
               if (all) {
                 output.metricScale = interval.scale;
-                output.metricScaleText = interval.preScaled.description;
+                output.metricScaleText = interval.preScaled?.description || '';
               }
             }
           },

src/plugins/data/public/search/aggs/buckets/lib/time_buckets/time_buckets.test.ts

@@ -0,0 +1,121 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+import moment from 'moment';
+
+import { TimeBuckets, TimeBucketsConfig } from './time_buckets';
+
+describe('TimeBuckets', () => {
+  const timeBucketConfig: TimeBucketsConfig = {
+    'histogram:maxBars': 4,
+    'histogram:barTarget': 3,
+    dateFormat: 'YYYY-MM-DD',
+    'dateFormat:scaled': [
+      ['', 'HH:mm:ss.SSS'],
+      ['PT1S', 'HH:mm:ss'],
+      ['PT1M', 'HH:mm'],
+      ['PT1H', 'YYYY-MM-DD HH:mm'],
+      ['P1DT', 'YYYY-MM-DD'],
+      ['P1YT', 'YYYY'],
+    ],
+  };
+
+  test('setBounds/getBounds - bounds is correct', () => {
+    const timeBuckets = new TimeBuckets(timeBucketConfig);
+    const bounds = {
+      min: moment('2020-03-25'),
+      max: moment('2020-03-31'),
+    };
+    timeBuckets.setBounds(bounds);
+    const timeBucketsBounds = timeBuckets.getBounds();
+
+    expect(timeBucketsBounds).toEqual(bounds);
+  });
+
+  test('setBounds/getBounds - bounds is undefined', () => {
+    const timeBuckets = new TimeBuckets(timeBucketConfig);
+    const bounds = {
+      min: moment('2020-03-25'),
+      max: moment('2020-03-31'),
+    };
+    timeBuckets.setBounds(bounds);
+    let timeBucketsBounds = timeBuckets.getBounds();
+
+    expect(timeBucketsBounds).toEqual(bounds);
+
+    timeBuckets.setBounds();
+    timeBucketsBounds = timeBuckets.getBounds();
+
+    expect(timeBucketsBounds).toBeUndefined();
+  });
+
+  test('setInterval/getInterval - intreval is a string', () => {
+    const timeBuckets = new TimeBuckets(timeBucketConfig);
+    timeBuckets.setInterval('20m');
+    const interval = timeBuckets.getInterval();
+
+    expect(interval.description).toEqual('20 minutes');
+    expect(interval.esValue).toEqual(20);
+    expect(interval.esUnit).toEqual('m');
+    expect(interval.expression).toEqual('20m');
+  });
+
+  test('setInterval/getInterval - intreval is a string and bounds is defined', () => {
+    const timeBuckets = new TimeBuckets(timeBucketConfig);
+    const bounds = {
+      min: moment('2020-03-25'),
+      max: moment('2020-03-31'),
+    };
+    timeBuckets.setBounds(bounds);
+    timeBuckets.setInterval('20m');
+    const interval = timeBuckets.getInterval();
+
+    expect(interval.description).toEqual('day');
+    expect(interval.esValue).toEqual(1);
+    expect(interval.esUnit).toEqual('d');
+    expect(interval.expression).toEqual('1d');
+    expect(interval.scaled).toBeTruthy();
+    expect(interval.scale).toEqual(0.013888888888888888);
+
+    if (interval.preScaled) {
+      expect(interval.preScaled.description).toEqual('20 minutes');
+      expect(interval.preScaled.esValue).toEqual(20);
+      expect(interval.preScaled.esUnit).toEqual('m');
+      expect(interval.preScaled.expression).toEqual('20m');
+    }
+  });
+
+  test('setInterval/getInterval - intreval is a "auto"', () => {
+    const timeBuckets = new TimeBuckets(timeBucketConfig);
+    timeBuckets.setInterval('auto');
+    const interval = timeBuckets.getInterval();
+
+    expect(interval.description).toEqual('0 milliseconds');
+    expect(interval.esValue).toEqual(0);
+    expect(interval.esUnit).toEqual('ms');
+    expect(interval.expression).toEqual('0ms');
+  });
+
+  test('getScaledDateFormat', () => {
+    const timeBuckets = new TimeBuckets(timeBucketConfig);
+    timeBuckets.setInterval('20m');
+    timeBuckets.getScaledDateFormat();
+    const format = timeBuckets.getScaledDateFormat();
+    expect(format).toEqual('HH:mm');
+  });
+});