Jersey has a great possibility to write integration tests for REST APIs, written with Jersey. Just extend the class JerseyTest and go for it.

I ran into an issue where I had to mock a SecurityContext so that the SecurityContext includes a special UserPrincipal. The challenge is that Jersey wraps the SecurityContext in an own class SecurityContextInjectee in tests. So I have to add my SecurityContext Mock to this Jersey's wrapper class. Let me demonstrate it in an example.

Let say I have the following Jersey Resource:

@Path("hello/world")
public class MyJerseyResource {

 @GET
 public Response helloWorld(@Context final SecurityContext context) {
  String name = context.getUserPrincipal().getName();
  return Response.ok("Hello " + name, MediaType.TEXT_PLAIN).build();
 }

}

In my test, I have to mock the SecurityContext, so that a predefined user principal can be used during the tests. I use Mockito as mocking framework. My mock looks like the following one

final SecurityContext securityContextMock = mock(SecurityContext.class);
when(securityContextMock.getUserPrincipal()).thenReturn(new Principal() {
 @Override
 public String getName() {
  return "Alice";
 }
});

For adding this mocked SecurityContext to the wrapper class SecurityContextInjectee, I have to configure a ResourceConfig with a modified ContainerRequestContext in my Jersey Test. The mocked SecurityContext can be set in this modified ContainerRequestContext and then it will be used in the wrapper class:

@Override
public Application configure() {
 final SecurityContext securityContextMock = mock(SecurityContext.class);
 when(securityContextMock.getUserPrincipal()).thenReturn(new Principal() {
  @Override
  public String getName() {
   return "Alice";
  }
 });

 ResourceConfig config = new ResourceConfig();
 config.register(new ContainerRequestFilter() {
  @Override
  public void filter(final ContainerRequestContext containerRequestContext) throws IOException {
   containerRequestContext.setSecurityContext(securityContextMock);
  }
 });
 return config;
}

Then, the whole test for my resource looks like the following one:

public class MyJerseyResourceTest extends JerseyTest {

 @Test
 public void helloWorld() throws Exception {
  Response response = target("hello/world").request().get();

  assertThat(response.getStatus()).isEqualTo(HttpStatus.SC_OK);
  assertThat(response.getEntity()), isEqualTo("Hello Alice");
 }

 @Override
 public Application configure() {
  final SecurityContext securityContextMock = mock(SecurityContext.class);
  when(securityContextMock.getUserPrincipal()).thenReturn(new Principal() {
   @Override
   public String getName() {
    return "Alice";
   }
  });

  ResourceConfig config = new ResourceConfig();
  config.register(new ContainerRequestFilter() {
   @Override
   public void filter(final ContainerRequestContext containerRequestContext) throws IOException {
    containerRequestContext.setSecurityContext(securityContextMock);
   }
  });
  return config;
 }

Do you have a smarter solution for this problem? Let me know it and write a comment below.