Mocking a constructor call

Hello Roman,

You can fake the constructor so it will not be executed, however you can't specify custom code to run instead.

You can use something like:

var fakeMyObject = Isolate.Fake.Instance<MyObject>(Members.CallOriginal, ConstructorWillBe.Ignored);

to create an instance of MyObject that will have all its methods call their original implementations, but the constructor will not be executed. Then you can fake a particular method and replace its logic with DoInstead.

Hope that helps.

Bummer... it would definitely be useful to specify a delegate to be executed when a constructor runs. Would be preferable to do it in a strongly-typed manner, though the following might work as well - Isolate.NonPublic.WhenCalled(obj, "MyObject") or Isolate.NonPublic.WhenCalled(obj, ".ctor").

The scenario I'm trying to set up is verifying that method calls occur within a transaction, i.e. set up a list of Actions and make sure that they haven't been called at the time that a TransactionScope object is instantiated and have been called at the time of TransactionScope.Complete().

I was able to get around this, because we have a custom container around TransactionScope, which happens to call a private _initialize method in the constructor and I could set up the DoInstead logic around _initialize. This is of course not ideal, as it exposes implementation.

Hi Roman,

There a workaround to this case using Isolator natural API (previous generation of the API). You can register to a type constructors calls with callback.

For example:

[Test]
public void CallBackOnCtorCalls()
{
    var mock = MockManager.MockAll<MyClass>();
    bool wasCalled = false;
    mock.MethodSettings(".ctor").MockMethodCalled += (sender, args) => wasCalled = true;

    Assert.IsFalse(wasCalled);

    new MyClass();

    Assert.IsTrue(wasCalled);
}

This code will notify when a class of MyClass type is initialized.

Please let us know if it helps to test the case you presented.

Regards,
Elisha,
Typemock Support