Restore line rendering in point series vis using percentile agg (#35649…

…) (#36684)

Restores the visualization's  line rendering when using a multi metric aggregation like percentile. Before this fix only dots were rendered
fixes #34858

src/legacy/ui/public/vislib/__tests__/lib/types/point_series.js

@@ -21,6 +21,8 @@ import ngMock from 'ng_mock';
 import expect from '@kbn/expect';
 import stackedSeries from 'fixtures/vislib/mock_data/date_histogram/_stacked_series';
 import { VislibTypesPointSeries } from '../../../lib/types/point_series';
+import percentileTestdata from './testdata_linechart_percentile.json';
+import percentileTestdataResult from './testdata_linechart_percentile_result.json';
 
 describe('Point Series Config Type Class Test Suite', function () {
   let pointSeriesConfig;
@@ -123,6 +125,20 @@ describe('Point Series Config Type Class Test Suite', function () {
     });
   });
 
+  describe('line chart', function () {
+    beforeEach(function () {
+      const percentileDataObj = {
+        get: (prop) => { return data[prop] || data.data[prop] ||  null; },
+        getLabels: () => [],
+        data: percentileTestdata.data
+      };
+      parsedConfig = pointSeriesConfig.line(percentileTestdata.cfg, percentileDataObj);
+    });
+    it('should render a percentile line chart', function () {
+      expect(JSON.stringify(parsedConfig)).to.eql(JSON.stringify(percentileTestdataResult));
+    });
+  });
+
 
   describe('heatmap chart', function () {
     beforeEach(function () {