[7.x] Median label shows "Median" instead of "50th percentile of" (#58521)

src/legacy/core_plugins/data/public/search/aggs/metrics/median.test.ts

@@ -47,7 +47,6 @@ describe('AggTypeMetricMedianProvider class', () => {
           schema: 'metric',
           params: {
             field: 'bytes',
-            percents: [70],
           },
         },
       ],
@@ -58,12 +57,21 @@ describe('AggTypeMetricMedianProvider class', () => {
   it('requests the percentiles aggregation in the Elasticsearch query DSL', () => {
     const dsl: Record<string, any> = aggConfigs.toDsl();
 
-    expect(dsl.median.percentiles.percents).toEqual([70]);
+    expect(dsl.median.percentiles.field).toEqual('bytes');
+    expect(dsl.median.percentiles.percents).toEqual([50]);
   });
 
-  it('asks Elasticsearch for array-based values in the aggregation response', () => {
-    const dsl: Record<string, any> = aggConfigs.toDsl();
+  it('converts the response', () => {
+    const agg = aggConfigs.getResponseAggs()[0];
 
-    expect(dsl.median.percentiles.keyed).toBeFalsy();
+    expect(
+      agg.getValue({
+        [agg.id]: {
+          values: {
+            '50.0': 10,
+          },
+        },
+      })
+    ).toEqual(10);
   });
 });

src/legacy/core_plugins/data/public/search/aggs/metrics/median.ts

@@ -43,17 +43,13 @@ export const medianMetricAgg = new MetricAggType({
       name: 'field',
       type: 'field',
       filterFieldTypes: [KBN_FIELD_TYPES.NUMBER, KBN_FIELD_TYPES.DATE],
-    },
-    {
-      name: 'percents',
-      default: [50],
-    },
-    {
       write(agg, output) {
-        output.params.keyed = false;
+        output.params.field = agg.getParam('field').name;
+        output.params.percents = [50];
       },
     },
   ],
-  getResponseAggs: percentilesMetricAgg.getResponseAggs,
-  getValue: percentilesMetricAgg.getValue,
+  getValue(agg, bucket) {
+    return bucket[agg.id].values['50.0'];
+  },
 });

src/legacy/core_plugins/data/public/search/aggs/metrics/percentiles_get_value.ts

@@ -24,7 +24,7 @@ export const getPercentileValue = <TAggConfig extends IResponseAggConfig>(
   agg: TAggConfig,
   bucket: any
 ) => {
-  const { values } = bucket[agg.parentId] && bucket[agg.parentId];
+  const { values } = bucket[agg.parentId];
 
   const percentile: any = find(values, ({ key }) => key === agg.key);
 

test/functional/apps/visualize/_metric_chart.js

@@ -78,7 +78,7 @@ export default function({ getService, getPageObjects }) {
     });
 
     it('should show Median', async function() {
-      const medianBytes = ['5,565.263', '50th percentile of bytes'];
+      const medianBytes = ['5,565.263', 'Median bytes'];
       //  For now, only comparing the text label part of the metric
       log.debug('Aggregation = Median');
       await PageObjects.visEditor.selectAggregation('Median', 'metrics');