How to check contents of parameters with Delphi Mocks Framework?

Question

I'm trying to test with Delphi Mocks framework a class that creates simple value objects and passes them to a collaborator. How to check contents of these objects?

General idea of the code is like this:

TData = class
  Code : string;
  Field1 : string;
  Field2 : string;
end;

IReceiver = interface
  procedure Process(aData : TData);
end;

TSUTClass = class
public
  procedure DoSomething(const aCode : string);
  property Receiver : IReceiver;
end;

So when a call to DoSomething is made, TSUTClass should make several instances of TData and pass them one by one to Receiver.Process. I can verify that correct count of calls is made with this setup:

Mock := TMock<IReceiver>;
Mock.Setup.Expect.Exactly('Process', ExpectedCount);

But how to check if values of Field1 and Field2 are correct?

score 3 · Accepted Answer · answered May 10 '14 at 09:36

The mock has a WillExecute method where you can pass an anonymous method that will execute when the mock is called. You can evaluate the passed TData objects. Unfortunately after a quick look it seems that you cannot combine the WillExecute with an expected call count.

With DSharp Mocks which is very similar to Delphi Mocks it would look like this:

var
  mock: Mock<IReceiver>;
  sut: TSUTClass;
  callCount: Integer;
begin
  sut := TSUTClass.Create(mock);

  callCount := 0;
  mock.Setup.WillExecute(
    function(const args: TArray<TValue>; const ReturnType: TRttiType): TValue
    var
      data: TData;
    begin
      Inc(callCount);
      data := args[0].AsType<TData>;
      case callCount of
        1:
        begin
          CheckEquals('xyz', data.Field1);
          CheckEquals('abc', data.Field2);
        end;
        2: ///...
      end;

    end).Exactly(2).WhenCallingWithAnyArguments.Process(nil);

  sut.DoSomething('x');
end;

At least in Delphi Mocks `args[0]` is `Self` - an instance of `IReceiver` - and `args[1]` is `TData`. — Teloah, May 10 '14 at 11:13
I know, but in DSharp mocks it's not because I found it worthless to have the Self pointer to a mock instance because it is stateless. — Stefan Glienke, May 10 '14 at 11:15
WillExecute seems to return a IWhen, not an IExpect - IOW, I can't do .Exactly(2) like in the example. — Brian Riley, Mar 19 '16 at 16:30

How to check contents of parameters with Delphi Mocks Framework?

1 Answers1