Question

I have objects that gets initialized by serializing an XML file.

I’m thinking of including the test data in the test project as an embedded resource instead of “hard-coding” the data in the test method itself.

Embedded Hard-coded approach:

[Test]
public void IsMale_CheckIfGenderIsMale_ReturnsTrue()
{
Human human = new Human();
human.Gender = Gender.Male;
Gender expected = Gender.Male;
Assert.IsTrue((human.Gender == expected));
}

XML approach:

[Test]
public void IsMale_CheckIfGenderIsMale_ReturnsTrue()
{
Human human = Human.Initialize("Human_Male.xml");
Gender expected = Gender.Male;
Assert.IsTrue((human.Gender == expected));
}

Which is a better approach?

Answer 1

We often use embedded xml files in our project for testing. Because we want to test the creation of objects using xml.

It is also good practice to separate the creation of objects from the class itself, for example:

Human human = HumanFactory.Create("Human_Male.xml");

The human class would then have a constructor which takes parameters like gender, and can be called from the HumanFactory class. It’s a separation of concerns that will keep the logic of your class separate from the mechanism of building it.

And when you need a human object for a test, you can choose either to create it directly or use the factory and create it from xml.

I would also simplify the HumanFactory class further, by giving it an xml string (or Stream) instead of a filename. This can make it easier to test – because you can just include the xml in your test code and not in a file:

Human human = HumanFactory.Create("<human gender="m"></human>");
Assert.AreEqual(human.Gender,  Gender.Male);

Otherwise your test depends on either:

1. the test setup code deploying the “Human_Male.xml” file to the file system, and removing it afterwards. Although Visual Studio test has a nice mechanism to do this (test settings deployment will copy files into the test run folder as part of the test run setup).
2. Including a path to the embedded resource in your test code. If you should ever restructure your project layout, you will need to change the test code to match. And make sure you use a relative path.