public void Problem1_FindTheBug()
{
var target = new Problem1();
int x = 5;
int y = 10;
var pointStruct = new MutablePointStruct() { X = x, Y = y };
var result = target.FindTheBug(pointStruct);
Assert.AreEqual(x * 2, result.X);
Assert.AreEqual(y * 2, result.Y);
Assert.AreNotSame(pointStruct, result);
}
public void Problem1_PointStruct_SideAffecting()
{
// Instantiate the problem
var target = new Problem1();
// Set up the test
int x = 5;
int y = 10;
var pointStruct = new MutablePointStruct() { X = x, Y = y };
var result = target.DoubleTheTargetPointStruct(pointStruct);
// Assert truths.
Assert.AreEqual(x * 2, result.X);
Assert.AreEqual(y * 2, result.Y);
}
/// <summary>
/// Find the bug below and fix it.
/// </summary>
/// <param name="pointStruct">
/// A target point struct.
/// </param>
/// <returns>
/// A modified point struct whose X and Y values are twice the original.
/// </returns>
public MutablePointStruct FindTheBug(MutablePointStruct pointStruct)
{
pointStruct.X *= 2;
pointStruct.Y *= 2;
return pointStruct;
}
/// <summary>
/// Modify the passed in point struct and return it such that the X and Y values are twice
/// their original values. Because we're using structs, we have to let the parameter escape
/// the method or our changes will never stick.
/// </summary>
/// <param name="pointStruct">
/// The point struct to modify.
/// </param>
/// <returns>
/// The modified point struct whose X and Y values are double those of the input.
/// </returns>
public MutablePointStruct DoubleTheTargetPointStruct(MutablePointStruct pointStruct)
{
var myNewStruct = new MutablePointStruct(pointStruct.X * 2, pointStruct.Y * 2);
return myNewStruct;
}
/// <summary>
/// Find the bug below and fix it.
/// </summary>
/// <param name="pointStruct">
/// A target point struct.
/// </param>
/// <returns>
/// A modified point struct whose X and Y values are twice the original.
/// </returns>
public MutablePointStruct FindTheBug(MutablePointStruct pointStruct)
{
pointStruct.X *= 2;
pointStruct.Y *= 2;
return(pointStruct);
}
/// <summary>
/// Modify the passed in point struct and return it such that the X and Y values are twice
/// their original values. Because we're using structs, we have to let the parameter escape
/// the method or our changes will never stick.
/// </summary>
/// <param name="pointStruct">
/// The point struct to modify.
/// </param>
/// <returns>
/// The modified point struct whose X and Y values are double those of the input.
/// </returns>
public MutablePointStruct DoubleTheTargetPointStruct(MutablePointStruct pointStruct)
{
var myNewStruct = new MutablePointStruct(pointStruct.X * 2, pointStruct.Y * 2);
return(myNewStruct);
}