Unit testing in Delphi - how are you doing it?

There are some add-ons for DUnit, maybe this is worth a new entry on SO. Two which I can put on the list now are

1. FastMM4 integration: Unit tests will automatically detect memory leaks (and other things), works with DUnit 9.3 and newer
2. OpenCTF is a 'component test framework' based on DUnit, it creates the tests dynamically for all components in the project's forms, frames and datamodules, and tests them using customized rules (open source)

DUnit is a xUnit type of unit testing framework to be used with win32 Delphi. Since Delphi 2005 DUnit is integrated to a certan point into the IDE. Other DUnit integration tools for the Delphi IDE can be found here. DUnit comes with documentation with examples.

You could take a look at the unit testing classes available in our SynCommons open source unit. It's used in our Open-Source framework for all regression tests. It's perhaps not the best, but it's worth taking a look at it.

See http://blog.synopse.info/post/2010/07/23/Unit-Testing-light-in-Delphi

In order to implement an unit test, you just declare a new test case by creating a class like this:

type
  TTestNumbersAdding = class(TSynTestCase)
  published
    procedure TestIntegerAdd;
    procedure TestDoubleAdd;
  end;

procedure TTestNumbersAdding.TestDoubleAdd;
var A,B: double;
    i: integer;
begin
  for i := 1 to 1000 do
  begin
    A := Random;
    B := Random;
    CheckSame(A+B,Adding(A,B));
  end;
end;

Then you create a test suit, and run it.

In the up-to-come 1.13 version, there is also a new logging mechanism with stack trace of any raised exception and such, just like MadExcept, using .map file content as source.

It's now used by the unit testing classes, so that any failure will create an entry in the log with the source line, and stack trace:

C:\Dev\lib\SQLite3\exe\TestSQL3.exe 0.0.0.0 (2011-04-13)
Host=Laptop User=MyName CPU=2*0-15-1027 OS=2.3=5.1.2600 Wow64=0 Freq=3579545
TSynLogTest 1.13 2011-04-13 05:40:25

20110413 05402559 fail  TTestLowLevelCommon(00B31D70) Low level common: TDynArray "" stack trace 0002FE0B SynCommons.TDynArray.Init (15148) 00036736 SynCommons.Test64K (18206) 0003682F SynCommons.TTestLowLevelCommon._TDynArray (18214) 000E9C94 TestSQL3 (163) 

The difference between a test suit without logging and a test suit with logging is only this:

procedure TSynTestsLogged.Failed(const msg: string; aTest: TSynTestCase);
begin
  inherited;
  with TestCase[fCurrentMethod] do
    fLogFile.Log(sllFail,'%: % "%"',
      [Ident,TestName[fCurrentMethodIndex],msg],aTest);
end;

The logging mechanism can do much than just log the testing: you can log recursive calls of methods, select the information you want to appear in the logs, profile the application from the customer side, writing published properties, TList or TCollection content as JSON into the log content, and so on...

The first time the .map file is read, a .mab file is created, and will contain all symbol information needed. You can send the .mab file with the .exe to your client, or even embed its content to the .exe. This .mab file is optimized: a .map of 927,984 bytes compresses into a 71,943 .mab file.

So this unit could be recognized as the natural child of DUnit and MadExcept wedding, in pure OpenSource. :)

Additional information is available on our forum. Feel free to ask. Feedback and feature requests are welcome! Works from Delphi 6 up to XE.