Fix: Make Event Hub PartitionReceiver tests more robust (#21)

tests/Tests/EventHub/PartitionReceiverTests.cs

@@ -1,3 +1,5 @@
+using System.Text.RegularExpressions;
+
 using Azure.Messaging.EventHubs;
 using Azure.Messaging.EventHubs.Consumer;
 using Azure.Messaging.EventHubs.Producer;
@@ -321,12 +323,16 @@ public async Task Starting_Position_Higher_Than_Latest_Event_Should_Fail()
 
  var expectedMessage = $"" +
  $"The supplied sequence number '{startingPositionSequenceNumber}' is invalid. " +
- $"The last sequence number in the system is '{lastEnqueuedSequenceNumber}'";
+ $"The last sequence number in the system is '";
 
- await act
- .Should()
- .ThrowAsync<ArgumentException>()
- .Where(e => e.Message.StartsWith(expectedMessage));
+ var exception = await act
+ .Should()
+ .ThrowAsync<ArgumentException>()
+ .Where(e => e.Message.StartsWith(expectedMessage));
+
+ var actualLastEnqueuedSequenceNumber = long.Parse(Regex.Match(exception.Which.Message, @"The last sequence number in the system is '(\d+)'").Groups[1].Value);
+
+ actualLastEnqueuedSequenceNumber.Should().BeGreaterThanOrEqualTo(lastEnqueuedSequenceNumber);
  }
 
  [TestMethod]