public async Task TestInsertTelemetryAndUpdateRobotsAsync_UpsertTelemetry_ExpectedExecutions(int numItems) { mockCosmosClientTelemetry.Setup(x => x.UpsertItemAsync(It.IsAny <RobotTelemetry>(), It.IsAny <PartitionKey>())).Throws(new Exception("invalid")); FleetManager fleetManager = new FleetManager(mockIotClient.Object, mockCosmosClientRobot.Object, telemetryHandler, mockLogger.Object); IEnumerable <RobotTelemetry> testTelemetry = GetTestTelemetry(numItems); // should not throw exception await fleetManager.InsertTelemetriesAndUpdateRobotsAsync(testTelemetry); mockCosmosClientTelemetry.Verify(x => x.UpsertItemAsync(It.IsAny <RobotTelemetry>(), It.IsAny <PartitionKey>()), Times.Exactly(numItems)); }