corrected tests and rely on the field's formatter instead of trying t…

…o return a nice string

src/ui/public/agg_types/__tests__/metrics/top_hit.js

@@ -88,7 +88,7 @@ describe('Top hit metric', function () {
       expect(topHitMetric.getValue(aggConfig, bucket)).to.be(null);
     });
 
-    it ('should return null if the field has no value', function () {
+    it ('should return undefined if the field does not appear in the source', function () {
       const bucket = {
         '1': {
           hits: {
@@ -104,7 +104,7 @@ describe('Top hit metric', function () {
       };
 
       init({ field: '@tags' });
-      expect(topHitMetric.getValue(aggConfig, bucket)).to.be(null);
+      expect(topHitMetric.getValue(aggConfig, bucket)).to.be(undefined);
     });
 
     it ('should return the field value from the top hit', function () {
@@ -126,7 +126,7 @@ describe('Top hit metric', function () {
       expect(topHitMetric.getValue(aggConfig, bucket)).to.be('aaa');
     });
 
-    it ('should return a stringified representation of the field value if it is an object', function () {
+    it ('should return the object if the field value is an object', function () {
       const bucket = {
         '1': {
           hits: {
@@ -144,10 +144,10 @@ describe('Top hit metric', function () {
       };
 
       init({ field: '@tags' });
-      expect(topHitMetric.getValue(aggConfig, bucket)).to.be(JSON.stringify({ label: 'aaa' }, null, ' '));
+      expect(topHitMetric.getValue(aggConfig, bucket)).to.eql({ label: 'aaa' });
     });
 
-    it ('should return a stringified representation of the field if it has more than one values', function () {
+    it ('should return an array if the field has more than one values', function () {
       const bucket = {
         '1': {
           hits: {
@@ -163,7 +163,50 @@ describe('Top hit metric', function () {
       };
 
       init({ field: '@tags' });
-      expect(topHitMetric.getValue(aggConfig, bucket)).to.be(JSON.stringify([ 'aaa', 'bbb' ], null, ' '));
+      expect(topHitMetric.getValue(aggConfig, bucket)).to.eql([ 'aaa', 'bbb' ]);
+    });
+
+    it ('should get the value from the doc_values field if the source does not have that field', function () {
+      const bucket = {
+        '1': {
+          hits: {
+            hits: [
+              {
+                _source: {
+                },
+                fields: {
+                  'machine.os': [ 'linux' ]
+                }
+              }
+            ]
+          }
+        }
+      };
+
+      init({ field: 'machine.os' });
+      expect(topHitMetric.getValue(aggConfig, bucket)).to.be('linux');
+    });
+
+    it ('should return null if the field is not in the source nor in the doc_values field', function () {
+      const bucket = {
+        '1': {
+          hits: {
+            hits: [
+              {
+                _source: {
+                  nope: 'aaa'
+                },
+                fields: {
+                  nope: [ 'aaa' ]
+                }
+              }
+            ]
+          }
+        }
+      };
+
+      init({ field: 'machine.os' });
+      expect(topHitMetric.getValue(aggConfig, bucket)).to.be(null);
     });
   });
 });

src/ui/public/agg_types/metrics/top_hit.js

@@ -1,48 +1,13 @@
 import _ from 'lodash';
-import AggTypesAggTypeProvider from 'ui/agg_types/agg_type';
+import MetricAggTypeProvider from 'ui/agg_types/metrics/metric_agg_type';
 import RegistryFieldFormatsProvider from 'ui/registry/field_formats';
 import topSortEditor from 'ui/agg_types/controls/top_sort.html';
 
 export default function AggTypeMetricTopProvider(Private) {
-  const AggType = Private(AggTypesAggTypeProvider);
+  const MetricAggType = Private(MetricAggTypeProvider);
   const fieldFormats = Private(RegistryFieldFormatsProvider);
 
-  _.class(TopHitAggType).inherits(AggType);
-  function TopHitAggType(config) {
-    TopHitAggType.Super.call(this, config);
-  }
-
-  TopHitAggType.prototype.getValue = function (agg, bucket) {
-    const hits = _.get(bucket, `${agg.id}.hits.hits`);
-    if (!hits || !hits.length) {
-      return null;
-    }
-    const path = agg.params.field.name;
-    let values = agg.vis.indexPattern.formatField(hits[0], path);
-    if (!_.isArray(values)) {
-      values = [ values ];
-    }
-
-    if (!values.length && hits[0].fields) {
-      // no values found in the source, check the doc_values fields
-      values = hits[0].fields[path] || [];
-    }
-
-    switch (values.length) {
-      case 0:
-        return null;
-      case 1:
-        return _.isObject(values[0]) ? JSON.stringify(values[0], null, ' ') : values [0];
-      default:
-        return JSON.stringify(values, null, ' ');
-    }
-  };
-
-  TopHitAggType.prototype.getFormat = function (agg) {
-    return fieldFormats.getDefaultInstance('string');
-  };
-
-  return new TopHitAggType({
+  return new MetricAggType({
     name: 'top_hits',
     title: 'Top Hit',
     makeLabel: function (aggConfig) {
@@ -87,7 +52,7 @@ export default function AggTypeMetricTopProvider(Private) {
         name: 'sortField',
         type: 'field',
         editor: null,
-        filterFieldTypes: ['number', 'date', 'ip',  'string'],
+        filterFieldTypes: [ 'number', 'date', 'ip',  'string' ],
         default: function (agg) {
           return agg.vis.indexPattern.timeFieldName;
         },
@@ -130,6 +95,24 @@ export default function AggTypeMetricTopProvider(Private) {
           }
         }
       }
-    ]
+    ],
+    getValue(agg, bucket) {
+      const hits = _.get(bucket, `${agg.id}.hits.hits`);
+      if (!hits || !hits.length) {
+        return null;
+      }
+      const path = agg.params.field.name;
+      let values = agg.vis.indexPattern.flattenHit(hits[0])[path];
+
+      if ((values === '' || values === null || values === undefined) && hits[0].fields) {
+        // no values found in the source, check the doc_values fields
+        values = hits[0].fields[path] || [];
+        if (!values.length) {
+          return null;
+        }
+      }
+
+      return values;
+    }
   });
 };