Elasticsearch: use type guards instead of checking types

public/app/plugins/datasource/elasticsearch/datasource.ts

@@ -51,6 +51,7 @@ import {
   isPipelineAggregationWithMultipleBucketPaths,
 } from './components/QueryEditor/MetricAggregationsEditor/aggregations';
 import { metricAggregationConfig } from './components/QueryEditor/MetricAggregationsEditor/utils';
+import { isMetricAggregationWithMeta } from './guards';
 import { trackAnnotationQuery, trackQuery } from './tracking';
 import {
   Logs,
@@ -801,7 +802,7 @@ export class ElasticDatasource
 
     if (target.bucketAggs) {
       for (const bucketAgg of target.bucketAggs) {
-        if (bucketAgg.type !== 'filters' && this.templateSrv.containsTemplate(bucketAgg.field)) {
+        if (isBucketAggregationWithField(bucketAgg) && this.templateSrv.containsTemplate(bucketAgg.field)) {
           return true;
         }
         if (this.objectContainsTemplate(bucketAgg.settings)) {
@@ -812,15 +813,7 @@ export class ElasticDatasource
 
     if (target.metrics) {
       for (const metric of target.metrics) {
-        if (
-          metric.type === 'count' ||
-          metric.type === 'bucket_script' ||
-          metric.type === 'raw_data' ||
-          metric.type === 'raw_document' ||
-          metric.type === 'logs' ||
-          metric.type === 'top_metrics' ||
-          metric.type === 'moving_avg'
-        ) {
+        if (!isMetricAggregationWithField(metric)) {
           continue;
         }
         if (metric.field && this.templateSrv.containsTemplate(metric.field)) {
@@ -829,7 +822,7 @@ export class ElasticDatasource
         if (metric.settings && this.objectContainsTemplate(metric.settings)) {
           return true;
         }
-        if (metric.type === 'extended_stats' && this.objectContainsTemplate(metric.meta)) {
+        if (isMetricAggregationWithMeta(metric) && this.objectContainsTemplate(metric.meta)) {
           return true;
         }
       }

public/app/plugins/datasource/elasticsearch/guards.test.ts

@@ -0,0 +1,23 @@
+import { Count, ExtendedStats } from './dataquery.gen';
+import { isMetricAggregationWithMeta } from './guards';
+
+describe('Type guards', () => {
+  test('Identifies metrics with meta attribute', () => {
+    const metric: ExtendedStats = {
+      id: 'test',
+      type: 'extended_stats',
+      meta: {
+        test: 'test',
+      },
+    };
+    expect(isMetricAggregationWithMeta(metric)).toBe(true);
+  });
+
+  test('Identifies metrics without meta attribute', () => {
+    const metric: Count = {
+      id: 'test',
+      type: 'count',
+    };
+    expect(isMetricAggregationWithMeta(metric)).toBe(false);
+  });
+});

public/app/plugins/datasource/elasticsearch/guards.ts

@@ -0,0 +1,8 @@
+import { ExtendedStats, MetricAggregation } from './dataquery.gen';
+
+export function isMetricAggregationWithMeta(metric: MetricAggregation): metric is ExtendedStats {
+  if (!metric || typeof metric !== 'object') {
+    return false;
+  }
+  return 'meta' in metric;
+}