Elasticsearch: Fixes localized dates in index pattern (#27351)

Fixes #8403

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

@@ -9,11 +9,15 @@ const intervalMap: any = {
 };
 
 export class IndexPattern {
+  private dateLocale = 'en';
+
   constructor(private pattern: any, private interval?: string) {}
 
   getIndexForToday() {
     if (this.interval) {
-      return toUtc().format(this.pattern);
+      return toUtc()
+        .locale(this.dateLocale)
+        .format(this.pattern);
     } else {
       return this.pattern;
     }
@@ -35,7 +39,7 @@ export class IndexPattern {
     const indexList = [];
 
     while (start.valueOf() <= endEpoch) {
-      indexList.push(start.format(this.pattern));
+      indexList.push(start.locale(this.dateLocale).format(this.pattern));
       start.add(1, intervalInfo.amount);
     }
 

public/app/plugins/datasource/elasticsearch/specs/index_pattern.test.ts

@@ -1,9 +1,12 @@
 ///<amd-dependency path="test/specs/helpers" name="helpers" />
 
 import { IndexPattern } from '../index_pattern';
-import { toUtc } from '@grafana/data';
+import { toUtc, getLocale, setLocale } from '@grafana/data';
 
 describe('IndexPattern', () => {
+  const originalLocale = getLocale();
+  afterEach(() => setLocale(originalLocale));
+
   describe('when getting index for today', () => {
     test('should return correct index name', () => {
       const pattern = new IndexPattern('[asd-]YYYY.MM.DD', 'Daily');
@@ -11,6 +14,17 @@ describe('IndexPattern', () => {
 
       expect(pattern.getIndexForToday()).toBe(expected);
     });
+
+    test('should format date using western arabic numerals regardless of locale', () => {
+      setLocale('ar_SA'); // saudi-arabic, formatting for YYYY.MM.DD looks like "٢٠٢٠.٠٩.٠٣"
+      const pattern = new IndexPattern('[asd-]YYYY.MM.DD', 'Daily');
+      const expected =
+        'asd-' +
+        toUtc()
+          .locale('en')
+          .format('YYYY.MM.DD');
+      expect(pattern.getIndexForToday()).toBe(expected);
+    });
   });
 
   describe('when getting index list for time range', () => {
@@ -33,6 +47,17 @@ describe('IndexPattern', () => {
 
         expect(pattern.getIndexList(from, to)).toEqual(expected);
       });
+
+      test('should format date using western arabic numerals regardless of locale', () => {
+        setLocale('ar_SA'); // saudi-arabic, formatting for YYYY.MM.DD looks like "٢٠٢٠.٠٩.٠٣"
+        const pattern = new IndexPattern('[asd-]YYYY.MM.DD', 'Daily');
+        const from = new Date(1432940523000);
+        const to = new Date(1433153106000);
+
+        const expected = ['asd-2015.05.29', 'asd-2015.05.30', 'asd-2015.05.31', 'asd-2015.06.01'];
+
+        expect(pattern.getIndexList(from, to)).toEqual(expected);
+      });
     });
   });
 });