如何在 Java 中使用 Powermockito 对实用程序 Class 进行单元测试

How to Unit Test a Utility Class with Powermockito in Java

我已经看到如何通过模拟静态方法对使用 Utility classes 的 classes 进行单元测试,但我一直无法弄清楚如何对实际的方法进行单元测试效用 Class.

这是实用程序Class

public class DbNameContextHolder {
    private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();

    public static void setDbName(String dbName){
        contextHolder.set(dbName);
    }

    public static String getDbName(){
        return (String) contextHolder.get();
    }

    public static void clearDbName(){
        contextHolder.remove();
    }
}

这是我到目前为止为单元测试所做的尝试

@RunWith(PowerMockRunner.class)
@PrepareForTest({DbNameContextHolder.class, ThreadLocal.class})
public class DbNameContextHolderTest {
    @SuppressWarnings("rawtypes")
    @Mock
    ThreadLocal threadLocalMock;

    @Before
    public void init() throws Exception{
        PowerMockito.whenNew(ThreadLocal.class).withNoArguments().thenReturn(threadLocalMock);

    }

    @Test
    public void setsDBName(){
        DbNameContextHolder.setDbName("someName");
        verify(threadLocalMock).set("someName");
    }

    @Test
    public void getsDbName(){
        DbNameContextHolder.getDbName();
        verify(threadLocalMock).get();
    }

    @Test
    public void clearsDBName(){
        DbNameContextHolder.clearDbName();
        verify(threadLocalMock).remove();
    }
}

如何模拟这样的实用程序 class?

根据评论中的建议,我测试了预期的结果。

    @RunWith(MockitoJUnitRunner.class)
    public class DbNameContextHolderTest {

    @Test
    public void setsAndGetsDBNameCorrectly(){
        DbNameContextHolder.setDbName("someName");
        String returnedName = DbNameContextHolder.getDbName();
        assertEquals("someName",returnedName);
    }

    @Test
    public void clearsDBName(){
        DbNameContextHolder.setDbName("someName");
        String returnedName = DbNameContextHolder.getDbName();
        assertEquals("someName",returnedName);
        DbNameContextHolder.clearDbName();
        returnedName = DbNameContextHolder.getDbName();
        assertNull(returnedName);
    }
}