PR

Author: Oleksandr Poliakov

tests/MongoDB.Driver.TestHelpers/OnlyOnceEnumerable.cs

@@ -464,10 +464,12 @@ public async Task BulkWrite_should_enumerate_requests_once([Values(false, true)]
                 processedRequests: new[] { processedRequest },
                 upserts: new List<BulkWriteOperationUpsert>());
             _operationExecutor.EnqueueResult<BulkWriteOperationResult>(operationResult);
-            var wrappedRequests = OnlyOnceEnumerable.Create(requests);
+            var wrappedRequests = new Mock<IEnumerable<WriteModel<BsonDocument>>>();
+            wrappedRequests.Setup(e => e.GetEnumerator()).Returns(((IEnumerable<WriteModel<BsonDocument>>)requests).GetEnumerator());
 
-            var result = async ? await subject.BulkWriteAsync(wrappedRequests) : subject.BulkWrite(wrappedRequests);
+            var result = async ? await subject.BulkWriteAsync(wrappedRequests.Object) : subject.BulkWrite(wrappedRequests.Object);
 
+            wrappedRequests.Verify(e => e.GetEnumerator(), Times.Once);
             result.Should().NotBeNull();
             result.RequestCount.Should().Be(1);
             result.ProcessedRequests.ShouldBeEquivalentTo(requests);