public MainViewModel()
 {
     _random = new Random();
     _themeNames = Directory.GetFiles(@"Themes", "*.xaml");
     CalculatorViewModel = new CalculatorViewModel();
     ChangeThemeCommand = new ActionCommand(ChangeTheme);
 }
 public void TestAdd()
 {
     var c = new CalculatorViewModel();
     c.InputSymbol('2'); c.InputSymbol(','); c.InputSymbol('1');
     c.AddCommand.Execute();
     c.InputSymbol('2'); c.InputSymbol(','); c.InputSymbol('0');
     c.EquateCommand.Execute();
     Assert.IsTrue(Decimal.Equals(c.Result, 4.1M));
 }
 public void TestMultiply()
 {
     var c = new CalculatorViewModel();
     c.InputSymbol('2'); c.InputSymbol(','); c.InputSymbol('0');
     c.PlusMinusCommand.Execute();
     c.MultiplyCommand.Execute();
     c.InputSymbol('2'); c.InputSymbol(','); c.InputSymbol('0');
     c.EquateCommand.Execute();
     Assert.IsTrue(Decimal.Equals(c.Result, -4.0M));
 }
 public void TestAddSubtractAndEquate()
 {
     var c = new CalculatorViewModel();
     c.InputSymbol('2'); c.InputSymbol(','); c.InputSymbol('1');
     c.PlusMinusCommand.Execute();
     c.AddCommand.Execute();
     c.InputSymbol('2'); c.InputSymbol(','); c.InputSymbol('0');
     c.SubtractCommand.Execute();
     c.InputSymbol('2'); c.InputSymbol(','); c.InputSymbol('0');
     c.EquateCommand.Execute();
     Assert.IsTrue(Decimal.Equals(c.Result, -2.1M));
 }
 public void TestEmptyInput()
 {
     var c = new CalculatorViewModel();
     c.Input = String.Empty;
     Assert.IsTrue(c.Input == "0");
 }