public void ForLoop_WithNullStep_ThrowsArguementNullException()
{
var i = new WriteableExpressionVariable(0);
Expression variable = i.expression;
Expression from = Expression.Constant(0);
Expression to = Expression.Constant(2);
Expression step = null;
var forLoop = new ForLoop(variable, from, to, step);
}
public void IsOver_AtStart_IsFalse()
{
var i = new WriteableExpressionVariable(0);
Expression variable = i.expression;
Expression from = Expression.Constant(0);
Expression to = Expression.Constant(2);
var forLoop = new ForLoop(variable, from, to);
Assert.IsFalse(forLoop.IsOver);
}
public void ForLoop_WithoutStep_SetsStepTo1()
{
var i = new WriteableExpressionVariable(0);
Expression variable = i.expression;
Expression from = Expression.Constant(0);
Expression to = Expression.Constant(2);
var forLoop = new ForLoop(variable, from, to);
var actual = (forLoop.Step as ConstantExpression).Value;
Assert.AreEqual(1, actual);
}
public void TakeStep_WhenCalled_ChangesVariableValue()
{
var i = new WriteableExpressionVariable(0);
Expression variable = i.expression;
Expression from = Expression.Constant(0);
Expression to = Expression.Constant(2);
var forLoop = new ForLoop(variable, from, to);
var notExpected = i.value;
forLoop.TakeStep();
var actual = i.value;
Assert.AreNotEqual(notExpected, actual);
}
public void IsOver_AtEnd_IsTrue()
{
var i = new WriteableExpressionVariable(0);
Expression variable = i.expression;
Expression from = Expression.Constant(0);
Expression to = Expression.Constant(2);
var forLoop = new ForLoop(variable, from, to);
forLoop.TakeStep();
forLoop.TakeStep();
forLoop.TakeStep();
Assert.IsTrue(forLoop.IsOver);
}
