Spock Power Mock 不返回 .thenAnswer { } 方法中指定的值

Question

我有一个具有public static void 方法的类。此方法使用不同类中的方法，此方法接受两个参数并返回一个List 值。

public class FirstClass {
    public static void doSomething() {
        List<String> values = SecondClass.getOrderedValuesBy(anotherMethod());
        // action 
    }

    private static String anotherMethod() {
        // some action
        return ""; // something that depends on action above.
    }
}

public class SecondClass {
    public static List<String> getOrderedValuesBy(String by) {
        List<String> values = new ArrayList<>();
        values.addAll(getOrderedValuesBy(by, true));
        return values;
    }

    private static List<String> getOrderedValuesBy(String by, boolean ordered) {
       // some action
    }
}

然后在为此编写一些测试时，我在SecondClass 上使用mockStatic 方法并将FirstClass 初始化为一个新对象，如下所示。

def "someTest"() {
    given:
    mockStatic(SecondClass)
    FirstClass firstClass = new FirstClass()
    when(SecondClass.getOrderedValuesBy(anyString()).thenAnswer {['some values'])}
}

它不会返回我想要的这些值，因为我需要在doSomething() void 方法中调用的一些私有方法中使用它们，并且作为参数，这些方法采用values 列表。有人知道我做错了什么，以及我如何操作在FirstClass中的void方法中调用的这个方法返回的值@

Answer 1

您可以同时使用thenReturn 或thenAnswer，这取决于您在返回值之前要做什么，正如@Jordan 所说。这是MCVE：

应用程序类：

package de.scrum_master.stackoverflow.q59993907;

import java.util.ArrayList;
import java.util.List;

public class SecondClass {
  public static List<String> getOrderedValuesBy(String by) {
    List<String> values = new ArrayList<>();
    values.addAll(getOrderedValuesBy(by, true));
    return values;
  }

  private static List<String> getOrderedValuesBy(String by, boolean ordered) {
    // some action
    List<String> result = new ArrayList<>();
    result.add("one");
    result.add("two");
    result.add("three");
    return result;
  }
}

package de.scrum_master.stackoverflow.q59993907;

import java.util.List;

public class FirstClass {
  public static void doSomething() {
    List<String> values = SecondClass.getOrderedValuesBy(anotherMethod());
    // action
    System.out.println(values);
  }

  private static String anotherMethod() {
    // some action
    return ""; // something that depends on action above.
  }
}

使用 PowerMockito 的 Spock 规范：

package de.scrum_master.stackoverflow.q59993907

import org.junit.runner.RunWith
import org.powermock.core.classloader.annotations.PrepareForTest
import org.powermock.modules.junit4.PowerMockRunner
import org.powermock.modules.junit4.PowerMockRunnerDelegate
import org.spockframework.runtime.Sputnik
import spock.lang.Specification

import static de.scrum_master.stackoverflow.q59993907.SecondClass.getOrderedValuesBy
import static org.mockito.ArgumentMatchers.anyString
import static org.powermock.api.mockito.PowerMockito.mockStatic
import static org.powermock.api.mockito.PowerMockito.when

@RunWith(PowerMockRunner)
@PowerMockRunnerDelegate(Sputnik)
@PrepareForTest(SecondClass)
class PowerMockStaticTest extends Specification {
  static final PrintStream originalSysOut = System.out
  PrintStream mockSysOut = Mock()

  def setup() {
    System.out = mockSysOut
  }

  def cleanup() {
    System.out = originalSysOut
  }

  def "no mock"() {
    when:
    FirstClass.doSomething()

    then:
    1 * mockSysOut.println(['one', 'two', 'three'])
  }

  def "when-thenAnswer"() {
    given:
    mockStatic(SecondClass)
    when(getOrderedValuesBy(anyString())).thenAnswer { ['thenAnswer'] }

    when:
    FirstClass.doSomething()

    then:
    1 * mockSysOut.println(['thenAnswer'])
  }

  def "when-thenReturn"() {
    given:
    mockStatic(SecondClass)
    when(getOrderedValuesBy(anyString())).thenReturn(['thenReturn'])

    when:
    FirstClass.doSomething()

    then:
    1 * mockSysOut.println(['thenReturn'])
  }
}