How can I test functions and procedures as they don't belong to classes in Delphi?

Question

I have several little functions in an old Unit called Utils.pas.

Now I'd like refactoring some of them, but I think it's better to write test before. With DUnit I think it's impossible without a class.

So I'd like to know how can I test them before refactoring?

Edit:

I thought it was impossible because I was trying to add a test case in Delphi using Test Case Wizard. See the picture bellow that there aren't any classes and methods, so I'm not be able to create it.

Answer 1

You can't test a standalone function using the wizard but it's not a problem to test a standalone function with DUnit.

Example

  //***** A Standalone function te be tested in a unit far, far away
  function Add(v1, v2: Integer): Integer;
  ...

  //***** A testclass to contain the testmethods calling our 
  //      standalone function     
  TTestAdd = class(TTestcase)
  published
    procedure AddingComplement_ShouldEqualZero;
    procedure AddingNegativeNumbers_ShouldBeLessThanZero
    ...
  end;

  implementation

  procedure TTestAdd.AddingComplement_ShouldEqualZero;
  begin
    // Setup, Execute & Verify
    CheckEquals(0, Utils.Add(-1, 1), 'Complement doesn''t add to zero');
  end;

  procedure TTestAdd.AddingNegativeNumbers_ShouldBeLessThanZero
  begin
    // Setup, Execute & Verify
    CheckEquals(-3, Utils.Add(-1, -2), 'Add doesn''t add');
  end;