Containers 12. DUnit patterns and tests

Original in Russian: http://18delphi.blogspot.ru/2013/03/dunit_9770.html

About containers. Table of contents

The previous series was here:
http://18delphi.blogspot.com/2015/03/a-little-about-using-dunit.html

We’ll develop the idea of testing of TIntStack and TStringStack. But we’ll do it with ONE mixin by removing duplicates of the following kind:

procedure TIntStackTest.DoIt;
const
 cEtalons : array [0..3] of integer = (10, 20, 3, 5);
var
 l_S : TIntStack;
 l_I : Integer;
begin
 l_S := TIntStack.Create;
 try
  for l_I := Low(cEtalons) to High(cEtalons) do
   l_S.Push(cEtalons[l_I]);
  for l_I := High(cEtalons) downto Low(cEtalons) do
   Check(l_S.Pop = cEtalons[l_I]);
 finally
  FreeAndNil(l_S);
 end;//try..finally
end;//TIntStackTest.DoIt

and:

procedure TStringStackTest.DoIt;
const
 cEtalons : array [0..5] of String = ('The ', 'cat ', 'sat ', 'on ', 'the ','mat'); .

var
 l_S : TStringStack;
 l_I : Integer;
begin
 l_S := TStringStack.Create;
 try
  for l_I := Low(cEtalons) to High(cEtalons) do
   l_S.Push(cEtalons[l_I]);
  for l_I := High(cEtalons) downto Low(cEtalons) do
   Check(l_S.Pop = cEtalons[l_I]);
 finally
  FreeAndNil(l_S);
 end;//try..finally
end;//TStringStackTest.DoIt

We draw the diagram as follows:

We get the following code:
SandBox.dpr:

program SandBoxTest;
 
uses
  TestFrameWork
  GUITestRunner,
  IntStack,
  IntStackTest,
  StringStack,
  StringStackTest,
  IntStackTestViaMixIn,
  StringStackTestViaMixIn
  ;
 
begin
 GUITestRunner.RunRegisteredTests;
end.

StackTest.imp.pas:

{$IfNDef StackTest_imp}
 
{$Define StackTest_imp}
 TEtalonData = ItemsHolder;
 
 _StackTest_ = {mixin} class(TTestCase)
 published
   procedure DoIt;
 protected
 // protected methods
   function GetEtalonData: TEtalonData; virtual; abstract;
   function ArrayToEtalon(const aData: array of _ItemType_): TEtalonData;
     {* Helper function appears since dynamic arrays can be automatically cast to open arrays, but not backwards}
 end;//_StackTest_
 
{$Else StackTest_imp}
 
procedure _StackTest_.DoIt;
var
 l_Etalons : TEtalonData;
 l_S : _StackType_;
 l_I : Integer;
begin
 l_S := _StackType_.Create;
 try
  l_Etalons := GetEtalonData;
  for l_I := Low(l_Etalons) to High(l_Etalons) do
   l_S.Push(l_Etalons[l_I]);
  for l_I := High(l_Etalons) downto Low(l_Etalons) do
   Check(l_S.Pop = l_Etalons[l_I]);
 finally
  FreeAndNil(l_S);
 end;//try..finally
end;
 
function _StackTest_.ArrayToEtalon(const aData: array of _ItemType_): TEtalonData;
var
 l_I : Integer;
begin
 SetLength(Result, Length(aData));
 for l_I := Low(aData) to High(aData) do
  Result[l_I] := aData[l_I];
end;

IntStackTestViaMixIn.pas:

unit IntStackTestViaMixIn;
 
interface
 
uses
  IntStack,
  TestFrameWork
  ;
 
type
 _StackType_ = TIntStack;
 {$Include StackTest.imp.pas}
 TIntStackTestViaMixIn = class(_StackTest_)
 protected
 // realized methods
   function GetEtalonData: TEtalonData; override;
 end;//TIntStackTestViaMixIn
 
implementation
 
uses
  SysUtils
  ;
 
{$Include StackTest.imp.pas}
 
function TIntStackTestViaMixIn.GetEtalonData: TEtalonData;
begin
 Result := ArrayToEtalon([10, 20, 3, 5, 6, 19, 21]);
end;
 
initialization
 TestFramework.RegisterTest(TIntStackTestViaMixIn.Suite);
 
end.

StringStackTestViaMixIn.pas:

unit StringStackTestViaMixIn;
 
interface
 
uses
  StringStack,
  TestFrameWork
  ;
 
type
 _StackType_ = TStringStack;
 {$Include StackTest.imp.pas}
 TStringStackTestViaMixIn = class(_StackTest_)
 protected
 // realized methods
   function GetEtalonData: TEtalonData; override;
 end;//TStringStackTestViaMixIn
 
implementation
 
uses
  SysUtils
  ;
 
{$Include StackTest.imp.pas}
 
function TStringStackTestViaMixIn.GetEtalonData: TEtalonData;
begin
 Result := ArrayToEtalon(['The ', 'cat ', 'sat ', 'on ', 'the ','mat']);
end;
 
initialization
 TestFramework.RegisterTest(TStringStackTestViaMixIn.Suite);
 
end.

We get tests:

As for me, it is cool :-)
Try it. May be you will like it.

It’s clear that we could to the same with native Generic's.

-- and then, may be, we’ll learn to multiply tests by parameterizing on input data. In a special post. We’ll see…