[Test]
public void SettingColorSetsColorAtPosition()
{
    floodFiller.SetColor(1, 1, Color.Red);
    Assert.AreEqual(Color.Red, colors[1, 1]);
}

[Test]
public void SettingColorSetsColorAtPosition()
{
    floodFiller.SetColor(1, 1, Color.Red);
    Assert.AreEqual(Color.Red, colors[1, 1]);
}

[Test]
public void SettingColorToSameColorLeavesItUnchanged()
{
    floodFiller.SetColor(1, 1, Color.Red);
    floodFiller.SetColor(1, 1, Color.Red);
    Assert.AreEqual(Color.Red, colors[1, 1]);
    Assert.AreEqual(0, floodFiller.ProcessedCount);
}

[Test]
public void SettingColorToSameColorLeavesItUnchanged()
{
    floodFiller.SetColor(1, 1, Color.Red);
    floodFiller.SetColor(1, 1, Color.Red);
    Assert.AreEqual(Color.Red, colors[1, 1]);
    Assert.AreEqual(0, floodFiller.ProcessedCount);
}

[Test]
public void SettingColorWhenAllColorsAreTheSameChangesThemAll()
{
    floodFiller.SetColor(1, 1, Color.Red);
    for (int x = 0; x < Width; x++)
        for (int y = 0; y < Height; y++)
            Assert.AreEqual(Color.Red, colors[x, y]);
    Assert.AreEqual(16, floodFiller.ProcessedCount);
}

[Test]
public void SettingColorWhenAllColorsAreTheSameChangesThemAll()
{
    floodFiller.SetColor(1, 1, Color.Red);
    for (int x = 0; x < Width; x++)
        for (int y = 0; y < Height; y++)
            Assert.AreEqual(Color.Red, colors[x, y]);
    Assert.AreEqual(16, floodFiller.ProcessedCount);
}

[Test]
public void SettingColorWhenBoardIsSplitChangesOnlyPart()
{
    SetFirstThreeColumnsToBlue();
    floodFiller.SetColor(1, 1, Color.Red);
    AssertFirstThreeColumnsAreRed();
    AssertRestOfTheColumnsAreBlack();
    Assert.AreEqual(12, floodFiller.ProcessedCount);
}

[Test]
public void SettingColorWhenBoardIsSplitChangesOnlyPart()
{
    SetFirstThreeColumnsToBlue();
    floodFiller.SetColor(1, 1, Color.Red);
    AssertFirstThreeColumnsAreRed();
    AssertRestOfTheColumnsAreBlack();
    Assert.AreEqual(12, floodFiller.ProcessedCount);
}