部分模拟子类的方法使其绕过超类构造函数

Question

我试图仅模拟 class (Collaborator) 的一个方法 (getValue) 扩展另一个 (Person)。但是，在设置 Expectations 块之后，模拟 class 的构造函数在调用此方法时不会执行 super(...)。

以下示例改编自此处显示的代码：http://jmockit.org/tutorial/Mocking.html#partial

对象 Collaborator c3 出现问题。最后一个 assert 失败了，我预计它会通过。

public class PartialMockingTest
{
   static class Person
   {
      final int id;

      Person() { this.id = -1; }
      Person(int id) { this.id = id; }

      int getId() { return id; }
   }          

   static class Collaborator extends Person
   {
       final int value;

       Collaborator() { value = -1; }
       Collaborator(int value) { this.value = value; }
       Collaborator(int value, int id) { super(id); this.value = value; }

       int getValue() { return value; }
       final boolean simpleOperation(int a, String b, Date c) { return true; }
   }

   @Test
   public void partiallyMockingAClassAndItsInstances()
   {
      final Collaborator anyInstance = new Collaborator();

      new Expectations(Collaborator.class) {{
         anyInstance.getValue(); result = 123;
      }};

      // Not mocked, as no constructor expectations were recorded:
      Collaborator c1 = new Collaborator();
      Collaborator c2 = new Collaborator(150);
      Collaborator c3 = new Collaborator(150, 20); 

      // Mocked, as a matching method expectation was recorded:
      assertEquals(123, c1.getValue());
      assertEquals(123, c2.getValue());
      assertEquals(123, c3.getValue());

      // Not mocked:
      assertTrue(c1.simpleOperation(1, "b", null));
      assertEquals(45, new Collaborator(45).value);
      assertEquals(20, c3.getId()); // java.lang.AssertionError: expected:<20> but was:<-1>
   }

}

我是不是做错了什么？这是一个错误吗？

Answer 1

我不太了解 Expectations 系统的内部结构，但在调试代码后我意识到在对象构造之前声明期望搞乱了构造函数的调用。

这样一来，如果您在构造后移动 Expectation，测试应该会通过

final Collaborator anyInstance = new Collaborator();

// Not mocked, as no constructor expectations were recorded:
Collaborator c1 = new Collaborator();
Collaborator c2 = new Collaborator(150);
Collaborator c3 = new Collaborator(150, 20);

new Expectations(Collaborator.class) {{
   anyInstance.getValue(); result = 123;
}};

// Mocked, as a matching method expectation was recorded:
assertEquals(123, c1.getValue());
assertEquals(123, c2.getValue());
assertEquals(123, c3.getValue());

// Not mocked:
assertTrue(c1.simpleOperation(1, "b", null));
assertEquals(45, new Collaborator(45).value);
assertEquals(20, c3.getId());  //it works now

部分模拟子类的方法使其绕过超类构造函数

Partial mocking a method of a subclass makes it bypass the superclass constructor

java

unit-testing

junit

mocking

jmockit