Isolator feature focus: Recursive Fakes
Here’s another feature Typemock Isolator has that no one else currently has: the ability to return fake objects from properties recursively (without the use of an auto mocking container for such a feat). this saved a lot of reperitive test code of creating stubs that return stubs that return some custom result.
For example, an object person has a manager which is also a person (which of course also has a manager etc..)
here’s how you can use this feature:
[Test,Isolated]
public void test()
{
Person person = Isolate.Fake.Instance<Person>(Members.ReturnRecursiveFakes);
Assert.IsNotNull(person.Manager.Manager.Manager.Manager);
}
This test will pass (Manager is null by default. look at the class in question below:
class Person
{
public string Name
{
get { return name; }
}
public Person Manager
{
get { return manager; }
}
private string name;
private Person manager;
}
Here is how you can return stub results from properties of the stubbed objects:
[Test,Isolated]
public void test()
{
Person person = Isolate.Fake.Instance<Person>(Members.ReturnRecursiveFakes);
Isolate.WhenCalled(() => person.Manager.Manager.Name)
.WillReturn("roy");
Assert.AreEqual("roy",person.Manager.Manager.Name);
}
Notice that:
-
By saying “ReturnRecursiveFakes” we are actually saying “I don’t care who uses this object and how from now on. It will return a fake when needed from all properties and the properties of the stubs as well.
-
We can still set stub results on the fakes on any level
If we wanted to only fake the Manager name and leave everything else intact we could just use a live object in the test like this:
[Test,Isolated]
public void test()
{
Person person = new Person();
Isolate.WhenCalled(() => person.Manager.Manager.Name)
.WillReturn("roy");
Assert.AreEqual("roy",person.Manager.Manager.Name);
}