Add Sample SAML Response in Test

Issue gh-17823

Signed-off-by: Josh Cummings <3627351+jzheaux@users.noreply.github.com>

Author: jzheaux

config/src/test/java/org/springframework/security/config/annotation/web/configurers/saml2/Saml2LogoutConfigurerTests.java

@@ -409,7 +409,9 @@ public void saml2LogoutRequestWhenCustomLogoutRequestHandlerThenUses() throws Ex
 		logoutRequest.setIssueInstant(Instant.now());
 		given(getBean(Saml2LogoutRequestValidator.class).validate(any()))
 			.willReturn(Saml2LogoutValidatorResult.success());
-		Saml2LogoutResponse logoutResponse = Saml2LogoutResponse.withRelyingPartyRegistration(registration).build();
+		Saml2LogoutResponse logoutResponse = Saml2LogoutResponse.withRelyingPartyRegistration(registration)
+			.samlResponse("samlResponse")
+			.build();
 		given(getBean(Saml2LogoutResponseResolver.class).resolve(any(), any())).willReturn(logoutResponse);
 		this.mvc.perform(post("/logout/saml2/slo").param("SAMLRequest", "samlRequest").with(authentication(this.user)))
 			.andReturn();

config/src/test/java/org/springframework/security/config/http/Saml2LogoutBeanDefinitionParserTests.java

@@ -306,7 +306,9 @@ public void saml2LogoutRequestWhenCustomLogoutRequestHandlerThenUses() throws Ex
 		logoutRequest.setIssueInstant(Instant.now());
 		given(getBean(Saml2LogoutRequestValidator.class).validate(any()))
 			.willReturn(Saml2LogoutValidatorResult.success());
-		Saml2LogoutResponse logoutResponse = Saml2LogoutResponse.withRelyingPartyRegistration(registration).build();
+		Saml2LogoutResponse logoutResponse = Saml2LogoutResponse.withRelyingPartyRegistration(registration)
+			.samlResponse("samlResponse")
+			.build();
 		given(getBean(Saml2LogoutResponseResolver.class).resolve(any(), any())).willReturn(logoutResponse);
 		this.mvc
 			.perform(post("/logout/saml2/slo").param("SAMLRequest", "samlRequest").with(authentication(this.saml2User)))