[Lens] Add median operation (#79453)

x-pack/plugins/lens/public/indexpattern_datasource/dimension_panel/dimension_editor.tsx

@@ -264,7 +264,11 @@ export function DimensionEditor(props: DimensionEditorProps) {
         <EuiListGroup
           className={sideNavItems.length > 3 ? 'lnsIndexPatternDimensionEditor__columns' : ''}
           gutterSize="none"
-          listItems={sideNavItems}
+          listItems={
+            // add a padding item containing a non breakable space if the number of operations is not even
+            // otherwise the column layout will break within an element
+            sideNavItems.length % 2 === 1 ? [...sideNavItems, { label: '\u00a0' }] : sideNavItems
+          }
           maxWidth={false}
         />
       </div>

x-pack/plugins/lens/public/indexpattern_datasource/dimension_panel/dimension_panel.test.tsx

@@ -993,9 +993,11 @@ describe('IndexPatternDimensionEditorPanel', () => {
         'Average',
         'Count',
         'Maximum',
+        'Median',
         'Minimum',
         'Sum',
         'Unique count',
+        '\u00a0',
       ]);
     });
 

x-pack/plugins/lens/public/indexpattern_datasource/operations/definitions/index.ts

@@ -18,6 +18,8 @@ import {
   SumIndexPatternColumn,
   maxOperation,
   MaxIndexPatternColumn,
+  medianOperation,
+  MedianIndexPatternColumn,
 } from './metrics';
 import { dateHistogramOperation, DateHistogramIndexPatternColumn } from './date_histogram';
 import { countOperation, CountIndexPatternColumn } from './count';
@@ -43,6 +45,7 @@ export type IndexPatternColumn =
   | AvgIndexPatternColumn
   | CardinalityIndexPatternColumn
   | SumIndexPatternColumn
+  | MedianIndexPatternColumn
   | CountIndexPatternColumn;
 
 export type FieldBasedIndexPatternColumn = Extract<IndexPatternColumn, { sourceField: string }>;
@@ -59,6 +62,7 @@ const internalOperationDefinitions = [
   averageOperation,
   cardinalityOperation,
   sumOperation,
+  medianOperation,
   countOperation,
   rangeOperation,
 ];

x-pack/plugins/lens/public/indexpattern_datasource/operations/definitions/metrics.tsx

@@ -87,6 +87,7 @@ export type SumIndexPatternColumn = MetricColumn<'sum'>;
 export type AvgIndexPatternColumn = MetricColumn<'avg'>;
 export type MinIndexPatternColumn = MetricColumn<'min'>;
 export type MaxIndexPatternColumn = MetricColumn<'max'>;
+export type MedianIndexPatternColumn = MetricColumn<'median'>;
 
 export const minOperation = buildMetricOperation<MinIndexPatternColumn>({
   type: 'min',
@@ -137,3 +138,15 @@ export const sumOperation = buildMetricOperation<SumIndexPatternColumn>({
       values: { name },
     }),
 });
+
+export const medianOperation = buildMetricOperation<MedianIndexPatternColumn>({
+  type: 'median',
+  displayName: i18n.translate('xpack.lens.indexPattern.median', {
+    defaultMessage: 'Median',
+  }),
+  ofName: (name) =>
+    i18n.translate('xpack.lens.indexPattern.medianOf', {
+      defaultMessage: 'Median of {name}',
+      values: { name },
+    }),
+});

x-pack/plugins/lens/public/indexpattern_datasource/operations/operations.test.ts

@@ -315,12 +315,12 @@ describe('getOperationTypesForField', () => {
               },
               Object {
                 "field": "bytes",
-                "operationType": "min",
+                "operationType": "max",
                 "type": "field",
               },
               Object {
                 "field": "bytes",
-                "operationType": "max",
+                "operationType": "min",
                 "type": "field",
               },
               Object {
@@ -338,6 +338,11 @@ describe('getOperationTypesForField', () => {
                 "operationType": "cardinality",
                 "type": "field",
               },
+              Object {
+                "field": "bytes",
+                "operationType": "median",
+                "type": "field",
+              },
             ],
           },
         ]