Mockito无法存根重载的void方法

Question

我正在使用某个抛出异常的库，并希望测试在抛出异常时我的代码行为是否正确。将其中一个重载方法截尾似乎不起作用。我得到了这个错误：Stubber不能应用于void。不存在变量类型T的实例类型，因此void确认为T

`public class AnotherThing {
  private final Something something;

  public AnotherThing(Something something) {
    this.something = something;
  }

  public void doSomething (String s) {
    something.send(s);
  }
}

public class Something {

  void send(String s) throws IOException{

  }

  void send(int i) throws IOException{

  }
}

import static org.mockito.Matchers.anyString;
import static org.mockito.Mockito.doThrow;
import static org.mockito.Mockito.mock;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.runners.MockitoJUnitRunner;

@RunWith(MockitoJUnitRunner.class)
public class OverloadedTest {

  @Test(expected = IllegalStateException.class)
  public void testDoSomething() throws Exception {
    final Something mock = mock(Something.class);
    final AnotherThing anotherThing = new AnotherThing(mock);

    doThrow(new IllegalStateException("failed")).when(anotherThing.doSomething(anyString()));
  }
}`

Answer 1

你把右括号放错了地方。当使用doverb().When()语法时，对When的调用应该只包含该对象，这使Mockito有机会停用被截断的期望，并且还防止Java认为您试图在任何地方传递void值。

doThrow(new IllegalStateException("failed"))
    .when(anotherThing.doSomething(anyString()));
//                    ^ BAD: Method call inside doVerb().when()

doThrow(new IllegalStateException("failed"))
    .when(anotherThing).doSomething(anyString());
//                    ^ GOOD: Method call after doVerb().when()

请注意，这与不使用doverb时调用when不同：

//               v GOOD: Method call inside when().thenVerb()
when(anotherThing.doSomethingElse(anyString()))
    .thenThrow(new IllegalStateException("failed"));