fix count and custom label on runtime fields (#95019)

Author: mattkime

src/plugins/data/common/index_patterns/index_patterns/__snapshots__/index_patterns.test.ts.snap

@@ -26,6 +26,25 @@ function setDocsourcePayload(id: string | null, providedPayload: any) {
   object = defaults(providedPayload || {}, stubbedSavedObjectIndexPattern(id));
 }
 
+const savedObject = {
+  id: 'id',
+  version: 'version',
+  attributes: {
+    title: 'kibana-*',
+    timeFieldName: '@timestamp',
+    fields: '[]',
+    sourceFilters: '[{"value":"item1"},{"value":"item2"}]',
+    fieldFormatMap: '{"field":{}}',
+    typeMeta: '{}',
+    type: '',
+    runtimeFieldMap:
+      '{"aRuntimeField": { "type": "keyword", "script": {"source": "emit(\'hello\')"}}}',
+    fieldAttrs: '{"aRuntimeField": { "count": 5, "customLabel": "A Runtime Field"}}',
+  },
+  type: 'index-pattern',
+  references: [],
+};
+
 describe('IndexPatterns', () => {
   let indexPatterns: IndexPatternsService;
   let savedObjectsClient: SavedObjectsClientCommon;
@@ -219,23 +238,14 @@ describe('IndexPatterns', () => {
   });
 
   test('savedObjectToSpec', () => {
-    const savedObject = {
-      id: 'id',
-      version: 'version',
-      attributes: {
-        title: 'kibana-*',
-        timeFieldName: '@timestamp',
-        fields: '[]',
-        sourceFilters: '[{"value":"item1"},{"value":"item2"}]',
-        fieldFormatMap: '{"field":{}}',
-        typeMeta: '{}',
-        type: '',
-      },
-      type: 'index-pattern',
-      references: [],
-    };
+    const spec = indexPatterns.savedObjectToSpec(savedObject);
+    expect(spec).toMatchSnapshot();
+  });
 
-    expect(indexPatterns.savedObjectToSpec(savedObject)).toMatchSnapshot();
+  test('correctly composes runtime field', async () => {
+    setDocsourcePayload('id', savedObject);
+    const indexPattern = await indexPatterns.get('id');
+    expect(indexPattern.fields).toMatchSnapshot();
   });
 
   test('failed requests are not cached', async () => {

src/plugins/data/common/index_patterns/index_patterns/index_patterns.test.ts

@@ -425,8 +425,9 @@ export class IndexPatternsService {
             runtimeField: value,
             aggregatable: true,
             searchable: true,
-            count: 0,
             readFromDocValues: false,
+            customLabel: spec.fieldAttrs?.[key]?.customLabel,
+            count: spec.fieldAttrs?.[key]?.count,
           };
         }
       }