Mockito -模拟正在测试的异步方法内部的方法

public class MyService {
    public CompletableFuture<String> performAsyncOperation() {
        return CompletableFuture.supplyAsync(() -> internalMethod());
    }

    public String internalMethod() {
        // 复杂的逻辑
        return "Real Result";
    }
}

import static org.mockito.Mockito.*;
import static org.junit.jupiter.api.Assertions.*;

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

public class MyServiceTest {

    @Mock
    private MyService myService;

    @InjectMocks
    private MyService myServiceUnderTest;

    @BeforeEach
    public void setUp() {
        MockitoAnnotations.openMocks(this);
    }

    @Test
    public void testPerformAsyncOperation() throws ExecutionException, InterruptedException {
        // 模拟 internalMethod 的行为
        when(myService.internalMethod()).thenReturn("Mocked Result");

        // 调用异步方法
        CompletableFuture<String> future = myServiceUnderTest.performAsyncOperation();

        // 等待异步操作完成并获取结果
        String result = future.get();

        // 验证结果
        assertEquals("Mocked Result", result);

        // 验证 internalMethod 被调用
        verify(myService).internalMethod();
    }
}