C# TDD交通信号灯的重构阶段-如何做到这一点？

因此，我对即将诞生的一个类

板
进行了以下测试：

[TestMethod]
public void Set_The_Origin_As_Violet_And_The_Query_Confirms_It() {
    Board board = new Board(10, 10);

    Color expected = Color.Violet;
    board.SetColorAt(0, 0, expected);
    Color actual = board.GetColorAt(0, 0);
    Assert.AreEqual(expected, actual);
}

我试着运行代码，但编译器表示
Board
不存在。所以我创造了它

我试图再次运行代码，但没有效果，因为SetColorAt（）和GetColorAt（）方法都不存在。我创造了它们：

public void SetColorAt(int x, int y, Color color) {
}

public void GetColorAt(int x, int y) {
}

不过，并不是每件事都很好，因为我必须把颜色改成紫色。所以我将GetColorAt（）改为

所以我第一次得到了绿灯

我希望我的最终代码出现在课程板上的形式如下：

public class Board
{
    private Color[,] board;

    public Board(int x, int y)
    {
        board = new Color[x, y];
    }

    public void SetColorAt(int x, int y, Color color) {
        board[x, y] = color;
    }

    public Color GetColorAt(int x, int y) {
        return board[x, y];
    }
}

我的第一个问题是。。。。
怎么去那里？我能在上面所示的单元测试的“重构”阶段中考虑到，当删除重复时，我最终会得到这个代码吗？
如果答案是肯定的，我觉得我的单元测试是在测试一些过于“本地化”的代码。你看，测试只是检查一个像素和一种颜色，而代码本身要复杂和丰富得多

也许解决方案是增加更多的单元测试？你建议做什么

我的第二个问题是。。。
我知道以后我会想要一个
IBoard
。我应该在上面的单元测试中表达这一点吗？我应该让他去吗

Board board = new Board(10, 10);

按原样创建
IBoard
界面？如何应对

public void GetColorAt(int x, int y) {
    return Color.Violet;
}

这里的return Color.Violet语句可以被视为数据重复，因此您可以重构这一部分。不过，最简单的方法是在调用SetColorAt时设置一个单色值

public class Board
{
    private Color theColor;

    public Board(int x, int y)
    {
    }

    public void SetColorAt(int x, int y, Color color) {
        theColor = color;
    }

    public Color GetColorAt(int x, int y) {
        return theColor;
    }
}

现在，您需要进行更多的测试，以显示您可以将单独的单元格设置为不同的颜色。
您熟悉测试模式，对吗？你的测试就是这么做的

[TestMethod]
public void Set_The_Origin_As_Violet_And_The_Query_Confirms_It() {
    // Arrange
    Board board = new Board(10, 10);
    // Act
    board.SetColorAt(0, 0, expected);
    // Assert
    Color expected = Color.Violet;
    Assert.AreEqual(expected, board.GetColorAt(0, 0));
}

我喜欢使用稍微修改过的表单，arrangeassertnotact-Assert。我们的想法是验证行为本身是导致我们测试的条件的原因，因为我们在行为之前断言我们的条件不满足。下面是它的外观：

[TestMethod]
public void Set_The_Origin_As_Violet_And_The_Query_Confirms_It() {
    // Arrange
    Board board = new Board(10, 10);
    // Assert
    Color expected = Color.Violet;
    Assert.AreNotEqual(expected, board.GetColorAt(0, 0));
    // Act
    board.SetColorAt(0, 0, expected);
    // Assert
    Assert.AreEqual(expected, board.GetColorAt(0, 0));
}

这迫使您在第一次编写稍微不那么简单的实现。您仍然需要额外的测试来驱动GetColorAt（）的完整实现；为此，我喜欢认为，编写完整实现的时候，要比在另一种特殊情况下（我想，对于这个应用程序，大概是N=3左右）假装的麻烦少一些。
从您想要实现的内容的高级描述开始


有行和列的正方形板
每个董事会职位都应该有一个
颜色
董事会用户应该能够
设置特定板的颜色
位置（像素）
董事会用户应
能够得到一张照片的颜色
具体董事会位置
等等

接下来，使用小测试来驱动实现。有时从边界条件开始比较容易

When asked to get the color at a specific board position
- given a default board, and
  - the row value is less than zero
  - should throw argument exception

When asked to get the color at a specific board position
- given a default board, and
  - the row value is greater than the highest board row
  - should throw argument exception

“行值大于最高的线路板行”强制您以某种方式设置最高的线路板行。测试并不关心您是通过构造函数还是属性设置器来设置它

When constructed with board dimensions
 - should set the highest board row

“应设置最高的线路板行”强制您以某种方式访问已设置的值。也许是一个属性获取者

When asked to get the color at a specific board position
- given a default board, and
  - the column value is less than zero
  - should throw argument exception

When asked to get the color at a specific board position
- given a default board, and
  - the column value is greater than the highest board column
  - should throw argument exception

“列值大于最高的board列”强制您为最高的列复制最高的行解决方案

When constructed with board dimensions
 - should set the highest board column

等等

“应返回默认颜色”强制您在某处显示默认颜色。这不应该是只有测试才知道的神奇值。将其公开为板上的常量或只读值

When asked to get the color at a specific board position
- given a default board, and
  - the row value is within the board space, and
  - the column is within the board space, and
  - the requested position has a known color
  - should return the color of the board at the requested position

“请求的位置具有已知颜色”强制您建立设置板位置颜色的能力。您现在可以这样做，因为您在某个位置获取颜色的测试失败。所以把它放在一边，建立起二传手

When asked to SET the color at a specific board position
- given a default board, and
  - the row value is less than zero
  - should throw argument exception

When asked to set the color at a specific board position
- given a default board, and
  - the row value is greater than the highest board row
  - should throw argument exception

When asked to set the color at a specific board position
- given a default board, and
  - the column value is less than zero
  - should throw argument exception

When asked to set the color at a specific board position
- given a default board, and
  - the column value is greater than the highest board column
  - should throw argument exception

When asked to set the color at a specific board position
- given a default board, and
  - the row value is within the board space, and
  - the column is within the board space
  - should set the color at the given position to the requested color

“应将给定位置的颜色设置为请求的颜色”使用get实现验证值设置是否正确。一旦您正确地实现了它，您的所有测试将再次变为绿色

只需继续构建附加功能，一次只构建一小部分

当您使用与实现无关的术语进行测试时，您可以将实现更改为使用IBoard或Ruby或其他任何东西，并且测试描述不必更改。您必须更改一些测试实施细节，但测试的既定目标不必更改。
我认为您编写了一个设置颜色并获得颜色的电路板，这是一次冒险。是什么驱动了一块木板？什么需要一块板来存储颜色？黑板是颜色的存储库

董事会有太多的实施细节。看，颜色是另一个对象的属性。你真的关心电路板存储颜色还是存储这个具有颜色属性的域对象。如果以后您也存储了董事会职位的历史记录，该怎么办。然后你要用两块板，一块是彩色板，然后是历史板

您确实需要将存储机制从实际依赖特定类型的颜色（紫色、蓝色、绿色等）中抽象出来

从理解问题域开始的问题是，它会将您的设计归档。而且它也不会如此强大

对我来说，我会从一个问题开始：颜色是什么域对象的属性？那么我的测试就会生成这个域对象。据我所知，域对象可能存在于板中，也可能不存在于板中

希望这对您有所帮助。
问题在于您从“这是正确的解决方案”开始。TDD是一种引导你做出好设计的技术，而不是预先确定的。我明白你的意思。但我想不出除了这个以外还有什么别的解决办法。您有一组（x，y）点，并且希望将它们存储在二维阵列中。这是实现t的最简单方法
When asked to get the color at a specific board position
- given a default board, and
  - the row value is within the board space, and
  - the column is within the board space, and
  - the requested position has a known color
  - should return the color of the board at the requested position

When asked to SET the color at a specific board position
- given a default board, and
  - the row value is less than zero
  - should throw argument exception

When asked to set the color at a specific board position
- given a default board, and
  - the row value is greater than the highest board row
  - should throw argument exception

When asked to set the color at a specific board position
- given a default board, and
  - the column value is less than zero
  - should throw argument exception

When asked to set the color at a specific board position
- given a default board, and
  - the column value is greater than the highest board column
  - should throw argument exception

When asked to set the color at a specific board position
- given a default board, and
  - the row value is within the board space, and
  - the column is within the board space
  - should set the color at the given position to the requested color