How do I unit test object serialization/deserialization in VB.NET 1.1?

Question

I am looking for example code that provides a unit test to serialize and deserialize an object from a memory stream. I have found examples using C# 2.0, however my current project uses VB.NET 1.1 (don't ask me why...), so the solution can not use generics. I am also using the NUnit framework for the unit tests.

Thanks!

score 2 · Accepted Answer · answered Jun 30 '09 at 14:30

2

This is the pattern I've settled upon:

<Test()> _
Public Sub SerializationTest()
    Dim obj As New MySerializableObject()
    'Perform additional construction as necessary

    Dim obj2 As MySerializableObject
    Dim formatter As New BinaryFormatter
    Dim memoryStream As New MemoryStream()

    'Run through serialization process
    formatter.Serialize(memoryStream, obj)
    memoryStream.Seek(0, SeekOrigin.Begin)
    obj2 = DirectCast(formatter.Deserialize(memoryStream), MySerializableObject)

    'Test for equality using Assert methods
    Assert.AreEqual(obj.Property1, obj.Property1)
    'etc...
End Sub

answered Jun 30 '09 at 14:30

Technobabble

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This looks like a case where using Theories would be helpful. From http://shareandenjoy.saff.net/tdd-specifications.pdf (which uses Java/Junit examples but the concepts are the same in NUnit) : "In our experience, good theories are usually identities of some kind. If a method must be added to write the identity, it usually fills an obvious gap in the existing API." In this case, the identity is "When I serialize an object, and then create a new one by deserializing that output, the new object should be identical to the original one." See http://www.nunit.org/index.php?p=theory&r=2.5.5 – Tyler Jun 09 '10 at 17:55

Patrik Hägne · Answer 2 · 2009-12-02T13:35:29.520

2

NUnit has built in support for this which makes it quite a bit easier:

Dim obj As New MySerializableObject()
Assert.That(obj, Is.BinarySerializable)

Or for xml:

Dim obj As New MySerializableObject()
Assert.That(obj, Is.XmlSerializable)

edited Dec 02 '09 at 13:35

answered Nov 12 '09 at 17:06

Patrik Hägne

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I had never known about this until now, just been using it, far better :) – MJJames Dec 01 '09 at 21:32

score 1 · Answer 3 · answered Nov 18 '08 at 17:27

1

If all you want to do is to ensure that they are serializable then all you should have to do it to do a serialization of an object and make sure no XmlSerializationException was thrown

[Test]
public void ClassIsXmlSerializable()
{
   bool exceptionWasThrown = false;

   try
   {
      // .. serialize object
   }
   catch(XmlSerializationException ex)
   {
      exceptionWasThrown = true;
   }

   Asset.IsFalse(exceptionWasThrown, "An XmlSerializationException was thrown. The type xx is not xml serializable!");
}

answered Nov 18 '08 at 17:27

TheCodeJunkie

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Sorry didnt see you were using VB.NET.. let me know if you want me to translate it to VB.NET for you – TheCodeJunkie Nov 18 '08 at 17:28
No need, I can read C# comfortably. However, I've run into some instances where VB.NET and C# differ consierably on certain features (like when using the [field:NonSerialized] attribute declaration, which doesn't seem to be supported in VB.NET). – Technobabble Nov 18 '08 at 17:36
If this was a solution to your problem then please make it as the answer – TheCodeJunkie Nov 18 '08 at 18:57

score 0 · Answer 4 · answered Nov 18 '08 at 17:05

0

Hmm...so you are trying to write a unit test for serialization? Or for streams? This is hopefully done by MS already...but if you don't trust or implement something on your own...you could just fill object with some data, save it, restore it, and check if the fields values are in place?

answered Nov 18 '08 at 17:05

Paul Kapustin

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Here is essentially what I'm trying to do, but in VB.NET 1.1: http://stackoverflow.com/questions/236599/how-to-unit-test-if-my-object-is-really-serializablable – Technobabble Nov 18 '08 at 17:15

How do I unit test object serialization/deserialization in VB.NET 1.1?

4 Answers4