I have this following custom interceptor in my java spring application as below.

public class AuthInterceptor implements ClientHttpRequestInterceptor {

    private final String encodedCredentials;

    public AuthInterceptor(String username, String password) {
        this(username, password, (Charset) null);
    }

    public AuthInterceptor(String username, String password, @Nullable Charset charset) {
        this.encodedCredentials = HttpHeaders.encodeBasicAuth(username, password, charset);
    }

    @Override
    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
        HttpHeaders headers = request.getHeaders();
        headers.setBasicAuth(this.encodedCredentials);
        return execution.execute(request, body);
    }

}

But I am looking to find for some documentation on how to write a unit test for this class and could not find. Any input on how to test would be really helpful

CodePudding user response：

Unit test that class the same way you unit test any class.

1. classToTest = new AuthInterceptor()
2. Call the method with Mock objects.

Some example code:

@ExtendWith(MockitoExtension.class)
public class TestAuthInterceptor
{
    private AuthInterceptor classToTest;

    @Mock
    private ClientHttpRequestExecution mockClientHttpRequestExecution;
    
    @Mock
    private ClientHttpResponse mockClientHttpResponse;
    
    @Mock
    private HttpHeaders mockHttpHeaders;
    
    @Mock
    private HttpRequest mockHttpRequest;

    @BeforeEach
    public void beforeEach()
    {
        classToTest = new AuthInterceptor("username", "password");
    }
    
    @Test
    public void intercept_allGood_success()
    {
        final ClientHttpResponse actualResult;
        final byte[] inputBody = null;
        
        doReturn(mockHttpHeaders).when(mockHttpRequest).getHeaders();
        doReturn(mockClientHttpResponse).when(mockClientHttpRequestExecution).execute(mockHttpRequest, inputBody);


        actualResult = classToTest.intercept(mockHttpRequest, inputBody, mockClientHttpRequestExecution);
        

        assertSame(mockClientHttpResponse, actualResult);
        // other asserts as desired.
    }
}

CodePudding user response：

Assuming you only want to test the interception and you already have set up mockito:

 @Test
  @DisplayName("Should add correct header to authorization")
  void encodeProperly() throws Exception {
    AuthInterceptor cut  = new AuthInterceptor("someuserName","somePaswwordName");

    MockHttpServletRequest request = new MockHttpServletRequest("GET", "/test");
    cut.intercept(request, null,null,mockedExecution );

    ArgumentCaptor<HttpRequest> argumentCapture = ArgumentCaptor.forClass(HttpRequest.class) ;
    verify(mockedExecution.execute(argumentCapture.capture(),any()));
    
    assertEquals(expectedEncodedCredentials,argumentCapture.getValue().getHeaders().get(HttpHeaders.AUTHORIZATION));
  }

so the steps are: create your class to test cut

then create a mock of MockHttpServletRequest it will be helpful to perform your check