@Test
    void verifyClientIdWithoutAnyAttributes() {
        val registeredService = getOidcRegisteredService(UUID.randomUUID().toString());
        servicesManager.save(registeredService);

        val credentials = new UsernamePasswordCredentials("oidctest", "oidctest");
        val request = new MockHttpServletRequest();
        request.addParameter(OAuth20Constants.CLIENT_ID, registeredService.getClientId());
        request.addParameter(OAuth20Constants.CLIENT_SECRET, registeredService.getClientSecret());
        val ctx = new JEEContext(request, new MockHttpServletResponse());
        authenticator.validate(new CallContext(ctx, new JEESessionStore()), credentials);
        assertNotNull(credentials.getUserProfile());
        assertEquals(1, credentials.getUserProfile().getAttributes().size());
        assertTrue(credentials.getUserProfile().getAttributes().containsKey(OAuth20Constants.CLIENT_ID));
    }
This is {@link OidcUsernamePasswordAuthenticatorTests}.

@author Misagh Moayyed
@since 7.0.0
support/cas-server-support-oidc/src/test/java/org/apereo/cas/oidc/authn/OidcUsernamePasswordAuthenticatorTests.java