碰撞单元试验

Question

我发现为我的冲突类编写单元测试有点乏味，因为有太多不同的冲突需要测试。在每个测试的设置和断言阶段，我都看到了重复，但我看不出如何在保持代码清晰简洁的同时减少重复。

package tests.kris {
  import asunitsrc.asunit.framework.TestCase;
  import flash.geom.Rectangle;
  import kris.RectangleCollision;
  public class RectangleCollisionTest extends TestCase {
    public function RectangleCollisionTest(testMethod:String):void {
      super(testMethod);
    }

    // detect
    public function detect_should_throw_error_when_both_arguments_are_the_same_object():void {
      var callOn:Rectangle = new Rectangle(0, 0, 0, 0);
      assertThrowsError(RectangleCollision.detect, callOn, callOn);
    }

    public function calling_detect_on_intersecting_rectangles_should_return_true():void {
      var callOn:Rectangle = new Rectangle(1, 1, 5, 5);
      var callWith:Rectangle = new Rectangle(2, 2, 5, 5);
      assertTrue(areColliding(callOn, callWith));
    }

    public function calling_detect_on_rectangles_with_a_touching_side_should_return_false():void {
      var callOn:Rectangle = new Rectangle(0, 0, 5, 5);
      var callWith:Rectangle = new Rectangle(5, 0, 5, 5);
      assertFalse(areColliding(callOn, callWith));
    }

    // Currently only works with rectangles that are rougly the same size and have shallow collisions

    // resolve
    public function calling_resolve_should_throw_error_when_both_arguments_are_the_same_object():void {
      var reactionary:Rectangle = newRectangle(0, 0, 0, 0);
      assertThrowsError(RectangleCollision.resolve, reactionary, reactionary);
    }

    public function calling_reslove_on_not_colliding_rectangles_returns_reactionary():void {
      var reactionary:Rectangle = new Rectangle(0, 0, 100, 100);
      var stationary:Rectangle = new Rectangle(200, 200, 100, 100);
      var result:Rectangle = RectangleCollision.resolve(reactionary, stationary);
      assertPosition(reactionary, 0, 0);
      assertPosition(stationary, 200, 200);
      assertPosition(result, 0, 0);
    }

    public function should_reslove_to_left_correctly_1():void {
      var reactionary:Rectangle = new Rectangle(2, 1, 100, 100);
      var stationary:Rectangle = new Rectangle(100, 0, 100, 100);
      var result:Rectangle = RectangleCollision.resolve(reactionary, stationary);
      assertPosition(reactionary, 2, 1);
      assertPosition(stationary, 100, 0);
      assertPosition(result, 0, 1);
    }

    public function should_reslove_to_left_correctly_2():void {
      var reactionary:Rectangle = new Rectangle(2, -1, 100, 100);
      var stationary:Rectangle = new Rectangle(100, 0, 100, 100);
      var result:Rectangle = RectangleCollision.resolve(reactionary, stationary);
      assertPosition(reactionary, 2, -1);
      assertPosition(stationary, 100, 0);
      assertPosition(result, 0, -1);
    }

    public function should_reslove_to_right_correctly_1():void {
      var reactionary:Rectangle = new Rectangle(98, 1, 100, 100);
      var stationary:Rectangle = new Rectangle(0, 0, 100, 100);
      var result:Rectangle = RectangleCollision.resolve(reactionary, stationary);
      assertPosition(reactionary, 98, 1);
      assertPosition(stationary, 0, 0);
      assertPosition(result, 100, 1);
    }

    public function should_reslove_to_right_correctly_2():void {
      var reactionary:Rectangle = new Rectangle(98, -1, 100, 100);
      var stationary:Rectangle = new Rectangle(0, 0, 100, 100);
      var result:Rectangle = RectangleCollision.resolve(reactionary, stationary);
      assertPosition(reactionary, 98, -1);
      assertPosition(stationary, 0, 0);
      assertPosition(result, 100, -1);
    }

    public function should_reslove_to_top_correctly_1():void {
      var reactionary:Rectangle = new Rectangle(1, 2, 100, 100);
      var stationary:Rectangle = new Rectangle(0, 100, 100, 100);
      var result:Rectangle = RectangleCollision.resolve(reactionary, stationary);
      assertPosition(reactionary, 1, 2);
      assertPosition(stationary, 0, 100);
      assertPosition(result, 1, 0);
    }

    public function should_reslove_to_top_correctly_2():void {
      var reactionary:Rectangle = new Rectangle(-1, 2, 100, 100);
      var stationary:Rectangle = new Rectangle(0, 100, 100, 100);
      var result:Rectangle = RectangleCollision.resolve(reactionary, stationary);
      assertPosition(reactionary, -1, 2);
      assertPosition(stationary, 0, 100);
      assertPosition(result, -1, 0);
    }

    public function should_reslove_to_bottom_correctly_1():void {
      var reactionary:Rectangle = new Rectangle(1, 98, 100, 100);
      var stationary:Rectangle = new Rectangle(0, 0, 100, 100);
      var result:Rectangle = RectangleCollision.resolve(reactionary, stationary);
      assertPosition(reactionary, 1, 98);
      assertPosition(stationary, 0, 0);
      assertPosition(result, 1, 100);
    }

    public function should_reslove_to_bottom_correctly_2():void {
      var reactionary:Rectangle = new Rectangle(-1, 98, 100, 100);
      var stationary:Rectangle = new Rectangle(0, 0, 100, 100);
      var result:Rectangle = RectangleCollision.resolve(reactionary, stationary);
      assertPosition(reactionary, -1, 98);
      assertPosition(stationary, 0, 0);
      assertPosition(result, -1, 100);
    }

    private function assertPosition(rect:Rectangle, x:Number, y:Number):void {
      assertEquals(x, rect.x);
      assertEquals(y, rect.y);
    }

    private function assertThrowsError(... args):void {
      assertTrue(functionThrowsError.apply(null, args));
    }

    private function functionThrowsError(functionToCall:Function, ... args):Boolean {
      try {
          functionToCall.apply(null, args);
          return false;
      } catch (error:Error) {
          return true;
      }
      throw new Error("Should not reach this point");
    }

    private function newRectangle(x:Number = 0, y:Number = 0, w:Number = 0, h:Number = 0):Rectangle {
      return new Rectangle(x, y, w, h);
    }

    private function areColliding(rectangle1:Rectangle, rectangle2:Rectangle):Boolean {
      return RectangleCollision.detect(rectangle1, rectangle2);
    }
  }
}

Answer 1

我不知道什么是最佳实践，但是您可以在安装方法中设置所需的矩形/位置/预期交叉点，这样测试itselfs就可以更短、更快地理解。

在过去的几周里，我自己写了一些交集单元测试，我知道有时候你会对测试应该做什么感到困惑。

此外，您可能应该检查退化的情况，即零宽度和/或高度的矩形。