import junit.framework.TestCase;

/**
 * A JUnit test case class.
 * Every method starting with the word "test" will be called when running
 * the test with JUnit.
 */
public class Test_IShape extends TestCase {
    double _tol = 1e-15;  // tolerance value for assertEquals using doubles
  
  /**
   * Test the Square class
   */
  public void test_Square() {
    Square s1 = new Square(5);
    assertEquals("Square(5).getArea()", 25.0, s1.getArea(), _tol);
    // Note that we don't have to assign an object to a variable to use it:
    assertEquals("Square(1.3).getArea()", 1.69, (new Square(1.3)).getArea(), _tol);
    assertEquals("Square(0).getArea()", 0, (new Square(0)).getArea(), _tol);
  }
  
  /**
   * Test the Circle class
   */
  public void test_Circle() {
    assertEquals("Circle(5).getArea()", Math.PI*25.0, (new Circle(5)).getArea(), _tol);
    assertEquals("Circle(1.3).getArea()", Math.PI*1.69, (new Circle(1.3)).getArea(), _tol);
    assertEquals("Circle(0).getArea()", 0, (new Circle(0)).getArea(), _tol);
  }
  
  /**
   * Test the Rectangle class
   */
  public void test_Rectangle() {
    assertEquals("Rectangle(5, 7).getArea()", 35.0, (new Rectangle(5, 7)).getArea(), _tol);
    assertEquals("Rectangle(1.3, 2.7).getArea()", 3.51, (new Rectangle(1.3, 2.7)).getArea(), _tol);
    assertEquals("Rectangle(0, 0).getArea()", 0, (new Rectangle(0, 0)).getArea(), _tol);
    assertEquals("Rectangle(0, Math.PI).getArea()", 0, (new Rectangle(0, Math.PI)).getArea(), _tol);
    assertEquals("Rectangle(Math.PI, 0).getArea()", 0, (new Rectangle(Math.PI, 0)).getArea(), _tol);
  }
  
  /**
   * Test the Triangle class
   */
  public void test_Triangle() {
    assertEquals("Triangle(5, 7).getArea()", 17.5, (new Triangle(5, 7)).getArea(), _tol);
    assertEquals("Triangle(1.3, 2.7).getArea()", 1.755, (new Triangle(1.3, 2.7)).getArea(), _tol);
    assertEquals("Triangle(0, 0).getArea()", 0, (new Triangle(0, 0)).getArea(), _tol);
    assertEquals("Triangle(0, Math.PI).getArea()", 0, (new Triangle(0, Math.PI)).getArea(), _tol);
    assertEquals("Triangle(Math.PI, 0).getArea()", 0, (new Triangle(Math.PI, 0)).getArea(), _tol);
  }
  
  /**
   * Test the IShape interface
   */
  public void test_IShape() {
    IShape s;   // s is an abstract shape
    
    // Notice how all the calculations below use the abstract IShape.getArea(),
    // not the getArea() from the concrete subclasses! 
    
    s = new Square(5);  // s refers to a square now
    assertEquals("Square(5): IShape.getArea()",25.0, s.getArea(), _tol); 
    
    s = new Circle(5);  // s refers to a circle now
    assertEquals("Circle(5): IShape.getArea()",Math.PI*25.0, s.getArea(), _tol);
    
    s = new Rectangle(5, 7); // s refers to a rectangle now
    assertEquals("Rectangle(5, 7): IShape.getArea()",35.0, s.getArea(), _tol); 
    
    s = new Triangle(5, 7);  // s refers to a triangle now
    assertEquals("Triangle(5, 7): IShape.getArea()",17.5, s.getArea(), _tol); 
  }
}