public void GetAndEvaluateIfExpression()
{
IfExpression expression = IfExpression.Instance;
Assert.IsNotNull(expression);
Machine machine = new Machine();
machine.Push(true);
machine.Push(new IntegerExpression(1));
machine.Push(new IntegerExpression(2));
expression.Evaluate(machine);
Assert.AreEqual(1, machine.StackCount);
Assert.AreEqual(1, machine.Pop());
machine.Push(false);
machine.Push(new IntegerExpression(1));
machine.Push(new IntegerExpression(2));
expression.Evaluate(machine);
Assert.AreEqual(1, machine.StackCount);
Assert.AreEqual(2, machine.Pop());
}
public void EvaluateElseExpression()
{
IfExpression ifexpr = new IfExpression(new ConstantExpression(false), new ConstantExpression(1), new ConstantExpression(2));
Assert.AreSame(TypeInfo.Int, ifexpr.TypeInfo);
Assert.AreEqual(2, ifexpr.Evaluate(null));
}
public void ExecuteThenWhenConditionIsZero()
{
IfExpression cmd = new IfExpression(new ConstantExpression(0), new AssignExpression("one", new ConstantExpression(1)));
Context context = new Context();
Assert.AreEqual(1, cmd.Evaluate(context));
Assert.AreEqual(1, context.GetValue("one"));
}
public void DontExecuteThenWhenConditionIsNull()
{
IfExpression cmd = new IfExpression(new ConstantExpression(null), new AssignExpression("one", new ConstantExpression(1)));
Context context = new Context();
Assert.IsNull(cmd.Evaluate(context));
Assert.IsNull(context.GetValue("one"));
}
public void ExecuteElseWhenConditionIsNull()
{
IfExpression cmd = new IfExpression(new ConstantExpression(null), new AssignExpression("one", new ConstantExpression(1)), new AssignExpression("two", new ConstantExpression(2)));
Context context = new Context();
Assert.AreEqual(cmd.Evaluate(context), 2);
Assert.IsNull(context.GetValue("one"));
Assert.AreEqual(2, context.GetValue("two"));
}