aggregation: Fix empty aggregation cursor count

neo9 · Oct 30, 2023 · a806892 · a806892
1 parent 84226e9
commit a806892
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Showing 2 changed files with 9 additions and 1 deletion.
diff --git a/src/cursors/n9-aggregation-cursor.ts b/src/cursors/n9-aggregation-cursor.ts
@@ -47,6 +47,7 @@ export class N9AggregationCursor<E> extends N9AbstractCursor<E> {
 				},
 			])
 			.toArray();
-		return countResult[0].n;
+		if (countResult.length > 0) return countResult[0].n;
+		return 0; // empty cursor
 	}
 }
diff --git a/test/aggregation-cursor.test.ts b/test/aggregation-cursor.test.ts
@@ -90,6 +90,13 @@ test('[Cursor] Check count function', async (t: ExecutionContext<ContextContent>
 		t.context.mongoClient.newAggregationBuilder().match(filterQuery).group({ _id: 1 }),
 	);
 	t.is(await cursor.count(), 1, 'cursor only contains the group result');
+
+	cursor = t.context.mongoClient.aggregateWithBuilder<SampleType>(
+		t.context.mongoClient
+			.newAggregationBuilder()
+			.match({ $and: [{ _id: { $eq: '1' } }, { _id: { $ne: '1' } }] }),
+	);
+	t.is(await cursor.count(), 0, 'empty cursor count is 0');
 });
 
 test('[Cursor] Check cursor clone function', async (t: ExecutionContext<ContextContent>) => {