public void AndExpressionReturnsTrueWhenBothOperandAreTrue()
{
{
IExpression left = new ConstantTerminalExpression(true);
IExpression right = new ConstantTerminalExpression(true);
IExpression and = new AndExpression(left, right);
Assert.AreEqual(true, and.Interpret(new Context()));
}
{
IExpression left = new VariableTerminalExpression("a");
IExpression right = new VariableTerminalExpression("b");
IExpression and = new AndExpression(left, right);
Assert.AreEqual(true, and.Interpret(new Context(new Dictionary <string, bool>()
{
{ "a", true }, { "b", true }
})));
}
{
// true && a => true for a = true
IExpression left = new ConstantTerminalExpression(true);
IExpression right = new VariableTerminalExpression("a");
IExpression and = new AndExpression(left, right);
Assert.AreEqual(true, and.Interpret(new Context(new Dictionary <string, bool>()
{
{ "a", true }
})));
}
{
// a && b => true for a = true and b = true
IExpression left = new VariableTerminalExpression("a");
IExpression right = new VariableTerminalExpression("b");
IExpression and = new AndExpression(left, right);
Assert.AreEqual(true, and.Interpret(new Context(new Dictionary <string, bool>()
{
{ "a", true }, { "b", true }
})));
}
}
public void AndExpressionReturnsFalseWhenBothOperandAreFalse()
{
{
IExpression left = new ConstantTerminalExpression(false);
IExpression right = new ConstantTerminalExpression(false);
IExpression and = new AndExpression(left, right);
Assert.AreEqual(false, and.Interpret(new Context()));
}
{
IExpression left = new VariableTerminalExpression("a");
IExpression right = new VariableTerminalExpression("b");
IExpression and = new AndExpression(left, right);
Assert.AreEqual(false, and.Interpret(new Context(new Dictionary <string, bool>()
{
{ "a", false }, { "b", false }
})));
}
{
// false && a => false for a = false
IExpression left = new ConstantTerminalExpression(false);
IExpression right = new VariableTerminalExpression("a");
IExpression and = new AndExpression(left, right);
Assert.AreEqual(false, and.Interpret(new Context(new Dictionary <string, bool>()
{
{ "a", false }
})));
}
{
// a && !b => false for a = false and b = true
IExpression left = new VariableTerminalExpression("a");
IExpression right = new NotExpression(new VariableTerminalExpression("b"));
IExpression and = new AndExpression(left, right);
Assert.AreEqual(false, and.Interpret(new Context(new Dictionary <string, bool>()
{
{ "a", false }, { "b", true }
})));
}
}