Check that transaction is not completed before attempting rollback

Signed-off-by: Eric Peterson <ericpeterson@spotify.com>

plugins/search-backend-module-pg/src/PgSearchEngine/PgSearchEngineIndexer.test.ts

@@ -23,6 +23,7 @@ describe('PgSearchEngineIndexer', () => {
   const tx = {
     rollback: jest.fn(),
     commit: jest.fn(),
+    isCompleted: jest.fn(),
   } as any;
   let database: jest.Mocked<DatabaseStore>;
   let indexer: PgSearchEngineIndexer;
@@ -37,6 +38,7 @@ describe('PgSearchEngineIndexer', () => {
       completeInsert: jest.fn(),
       prepareInsert: jest.fn(),
     };
+    tx.isCompleted.mockReturnValue(false);
     indexer = new PgSearchEngineIndexer({
       batchSize: 100,
       type: 'my-type',

plugins/search-backend-module-pg/src/PgSearchEngine/PgSearchEngineIndexer.ts

@@ -113,11 +113,10 @@ export class PgSearchEngineIndexer extends BatchSearchEngineIndexer {
       return;
     }
 
-    try {
-      this.tx!.rollback(error);
-    } catch {
-      // Unlikely! It was likely rolled back earlier.
+    if (!this.tx!.isCompleted()) {
+      await this.tx!.rollback(error);
     }
+
     done(error);
   }
 }