public void Replace_ReplacingExistingBoundVariableInComplexExpression_ShouldReturnTrueForChildrenContainingReplacedVariable()
{
// Arrange
char variableToBeReplaced = 'w';
List <char> variablesSetOne = new List <char>()
{
'u',
variableToBeReplaced
};
// Does not contain the replacement variable
List <char> variablesSetTwo = new List <char>()
{
'v',
'x'
};
Predicate predicateWithReplacementVariable = new Predicate(PREDICATE_SYMBOL, variablesSetOne);
// So we have unique references
Predicate predicateWithoutReplacementVariableOne = new Predicate(PREDICATE_SYMBOL, variablesSetTwo);
Predicate predicateWithoutReplacementVariableTwo = new Predicate(PREDICATE_SYMBOL, variablesSetTwo);
BinaryConnective root = new Conjunction();
BinaryConnective rootLeft = new BiImplication();
rootLeft.LeftSuccessor = predicateWithoutReplacementVariableOne;
rootLeft.RightSuccessor = predicateWithReplacementVariable;
root.LeftSuccessor = rootLeft;
root.RightSuccessor = predicateWithoutReplacementVariableTwo;
char replacementVariable = 'c';
// Act
root.Replace(variableToBeReplaced, replacementVariable);
bool isReplacedOnPredicateWithVariable = predicateWithReplacementVariable.IsReplaced(variableToBeReplaced);
bool isReplacedOnPredicateWithoutVariableOne = predicateWithoutReplacementVariableOne.IsReplaced(variableToBeReplaced);
bool isReplacedOnPredicateWithoutVariableTwo = predicateWithoutReplacementVariableTwo.IsReplaced(variableToBeReplaced);
// Assert
isReplacedOnPredicateWithVariable.Should().BeTrue($"Since the bound variable {variableToBeReplaced} should be repalced replaced by {replacementVariable}");
isReplacedOnPredicateWithoutVariableOne.Should().BeFalse($"Since the predicate does NOT contain {variableToBeReplaced}");
isReplacedOnPredicateWithoutVariableTwo.Should().BeFalse($"Since the predicate does NOT contain {variableToBeReplaced}");
}