如何验证一个android.util.Log.i(a，b)被调用

Question

在安卓应用程序中，有一些地方使用android.util.Log记录一些数据，并希望验证数据是否已被记录。

例如，拥有静态助手函数printOutIntent，，它在内部调用Log.i()

public class Utils{

    public static void printOutIntent(Intent intent, String TAG, boolean isDebug) {
        if (isDebug) {
            StringBuilder body = new StringBuilder();
            Bundle bundle = (intent != null) ? intent.getExtras() : new Bundle();
            if (bundle != null) {
                for (String key : bundle.keySet()) {
                    Object value = bundle.get(key);
                    body.append(key).append("=").append(value.toString()).append("\n");
                }
            }
            Log.i(TAG, body.toString());
        }
    }
}

在测试中，

@RunWith(RobolectricTestRunner.class)
public class TestTest {

   @Test
    public void test_logIntent() throws Exception {
        // setup
        final String others = "{\"key2-1\":\"val2-1\",\"key-2-2\":\"val2-2\"" +
                "}";
        Intent intent = new Intent();
        intent.putExtra("key", "test_val");
        intent.putExtra("key2", others);

        StringBuilder body = new StringBuilder();
        Bundle bundle = (intent != null) ? intent.getExtras() : new Bundle();
        if (bundle != null) {
            for (String key : bundle.keySet()) {
                Object value = bundle.get(key);
                body.append(key).append("=").append(value.toString()).append("\n");
            }
        }

        String dataStr = body.toString();

        ArgumentCaptor<String> requestCaptor = ArgumentCaptor.forClass(String.class);
        Utils mockedUtils = mock(Utils.class);
        android.util.Log theLog = mock(android.util.Log.class);

        mockedUtils.printOutIntent(intent, "TEST", true);

        verify(theLog, times(1)).i(eq("TEST"), requestCaptor.capture());
        String logStr = requestCaptor.getValue();
        assertEquals("log should be same.", dataStr, logStr);

    }
}

verify(theLog, times(1)).i(eq("TEST"), requestCaptor.capture());是成功的，但是requestCaptor.getValue()没有返回任何东西。

如何用正确的数据记录andriod.util.Log.i()？

Answer 1

找到一种方法(应该有更好的方法)，如果类/数据是通过某些类提供的，则必须模拟它们。

@RunWith(PowerMockRunner.class)
@PrepareForTest({Log.class,
        OtherData.class,
        Bundle.class,
        Intent.class}) {

@Test
public void test_logIntent() throws Exception {
        // setup
        final String others = "{\"key2-1\":\"val2-1\",\"key-2-2\":\"val2-2\"" +
        "}";

        Bundle bundleMock = mock(Bundle.class);
        when(bundleMock.keySet()).thenReturn(key);
        when(bundleMock.get("key1")).thenReturn("val1");
        when(bundleMock.get("key2")).thenReturn("val2");
        when(bundleMock.get("others")).thenReturn(others);

        Intent intentMock = mock(Intent.class);
        when(intentMock.getExtras()).thenReturn(bundleMock);
        
        // if there is other class which could return Intent in the code path, it needs to be mocked as well, i.e.
        /*
        OtherData otherDataMock = mock(OtherData.class);
        when(otherDataMock.toIntent()).thenReturn(intentMock);

        Intent intent = (otherDataMock != null) ? otherDataMock.toIntent() : null;
        */

        Intent intent = intentMock;

        StringBuilder body = new StringBuilder();
        Bundle bundle = (intent != null) ? intent.getExtras() : bundleMock;
        if (bundle != null) {
            for (String key : bundle.keySet()) {
                Object value = bundle.get(key);
                body.append(key).append("=").append(value.toString()).append("\n");
            }
        }

        String dataStr = body.toString();
        PowerMockito.mockStatic(Log.class);

        //test
        Utils.printOutIntent(intent, "TEST1", true);

        PowerMockito.verifyStatic(times(1));
        android.util.Log.i(eq("+++TEST1"), eq(dataStr));

        }
     }