What about automated testing?

You know that testing is (almost) everything if you want to avoid regression problems in your application.

How can you be confident that any change made to your software code won't create any error in other part of the software?

So automated unit testing is the good candidate for implementing this.

And even better, test-driven coding is great:
0. write a void implementation of a feature, that is code the interface with no implementation;
1. write a test code;
2. launch the test - it must fail;
3. implement the feature;
4. launch the test - it must pass;
5. add some features, and repeat all previous tests every time you add a new feature.

It could sounds like a waste of time, but such coding improve your code quality a lot, and, at least, it help you write and optimize every implementation feature.

But don't forget that unit testing is not enough: you have to do tests with your real application, and perform tasks like any user, in order to validate it works as expected.
That's why we added the writing and cross-referencing of test protocols in our SynProject documentation tool.

So how is testing implemented in our framework?

We may have used DUnit - http://sourceforge.net/projects/dunit

But we didn't like the fact that it relies on IDE and create separated units for testing.
We find it useful to make tests in pure code, in the same unit which implement them. Smartlinking feature of the Delphi compiler won't put the testing code in your final application, so it won't inflate your executable size.
And we don't like visual interfaces with red or green lights... we prefer text files and command line.
And DUnit code is bigger than ours, and we don't need so many options, following the KISS principle we like so much.
All this is a matter of taste - you can not agree, that's fine.

Among other features of these class, the main is that it is pretty well integrated with other cross-cutting features of the mORMot framewok:

So what about using RTTI for adding tests to your program?

In order to define tests, some TSynTestCase children must be defined, and will be launched by a TSynTests instance to perform all the tests. A text report is created on the current console, providing statistics and Pass/Fail.

First steps in testing

Here are the functions we want to test:

function Add(A,B: double): Double; overload;
begin
  result := A+B;
end;
function Add(A,B: integer): integer; overload;
begin
  result := A+B;
end;
function Multiply(A,B: double): Double; overload;
begin
  result := A*B;
end;
function Multiply(A,B: integer): integer; overload;
begin
  result := A*B;
end;

So we create three classes one for the whole test suit, one for testing addition, one for testing multiplication:

type
  TTestNumbersAdding = class(TSynTestCase)
  published
    procedure TestIntegerAdd;
    procedure TestDoubleAdd;
  end;
  TTestNumbersMultiplying = class(TSynTestCase)
  published
    procedure TestIntegerMultiply;
    procedure TestDoubleMultiply;
  end;
  TTestSuit = class(TSynTests)
  published
    procedure MyTestSuit;
  end;

The trick is to create published methods, each containing some tests to process.

Here is how one of these test methods are implemented (I let you guess the others):

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;

The CheckSame() is necessary because of floating-point precision problem, we can't trust plain = operator (i.e. Check(A+B=Adding(A,B)) will fail because of rounding problems).

And here is the test case implementation:

procedure TTestSuit.MyTestSuit;
begin
  AddCase([TTestNumbersAdding,TTestNumbersMultiplying]);
end;

And the main program (this .dpr is expected to be available as a console program):

  with TTestSuit.Create do
  try
    ToConsole := @Output; // so we will see something on screen
    Run;
    readln;
  finally
    Free;
  end;

Just run this program, and you'll get:


   Suit
  ------

1. My test suit

1.1. Numbers adding:
- Test integer add: 1,000 assertions passed  92us
- Test double add: 1,000 assertions passed  125us
Total failed: 0 / 2,000  - Numbers adding PASSED  360us

1.2. Numbers multiplying:
- Test integer multiply: 1,000 assertions passed  73us
- Test double multiply: 1,000 assertions passed  117us
Total failed: 0 / 2,000  - Numbers multiplying PASSED  324us

Generated with: Delphi 7 compiler

Time elapsed for all tests: 1.51ms
Tests performed at 25/03/2014 10:59:33
Total assertions failed for all test suits:  0 / 4,000
All tests passed successfully.

You can see that all text on screen was created by "UnCamelCasing" the method names (thanks to our good old Camel), and that the test suit just follows the order defined when registering the classes.
Each method has its own timing, which is pretty convenient to track performance regressions.

This test program has been uploaded in the SQLite3\Sample\07 - SynTest folder of the Source Code Repository.

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