Fix source command detection if we have a field expression before source (#10598)

* Fix source command detection if we have a field expression before source

Signed-off-by: Suchit Sahoo <suchsah@amazon.com>

* Changeset file for PR #10598 created/updated

---------

Signed-off-by: Suchit Sahoo <suchsah@amazon.com>
Co-authored-by: opensearch-changeset-bot[bot] <154024398+opensearch-changeset-bot[bot]@users.noreply.github.com>

Author: LDrago27

changelogs/fragments/10598.yml

@@ -0,0 +1,2 @@
+fix:
+- Source command detection if we have a field expression before source ([#10598](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/10598))

src/plugins/explore/public/application/utils/languages/ppl/get_query_string_with_source/get_query_with_source.test.ts

@@ -221,4 +221,14 @@ describe('getQueryWithSource', () => {
     const result = getQueryWithSource(query);
     expect(result).toEqual(query);
   });
+
+  it('should handle if we have a field Expression infront of SOURCE command', () => {
+    const query: Query = {
+      query: 'unique_category = "Configuration" source = `data_logs_small_time_1*`',
+      dataset: { title: 'test-dataset', id: '123', type: 'INDEX_PATTERN' },
+      language: 'ppl',
+    };
+    const result = getQueryWithSource(query);
+    expect(result).toEqual(query);
+  });
 });

src/plugins/explore/public/application/utils/languages/ppl/get_query_string_with_source/get_query_with_source.ts

@@ -12,7 +12,7 @@ import { QueryWithQueryAsString } from '../../types';
 export const getQueryWithSource = (query: Query): QueryWithQueryAsString => {
   const queryString = typeof query.query === 'string' ? query.query : '';
   const lowerCaseQuery = queryString.toLowerCase();
-  const hasSource = /^\s*(search\s+)?source\s*=/.test(lowerCaseQuery);
+  const hasSource = /^[^|]*\bsource\s*=/.test(lowerCaseQuery);
   const hasDescribe = /^\s*describe\s+/.test(lowerCaseQuery);
   const hasShow = /^\s*show\s+/.test(lowerCaseQuery);