Review comments

Author: dagnir

services-custom/sns-message-manager/src/main/java/software/amazon/awssdk/messagemanager/sns/internal/SnsHostProvider.java

@@ -27,6 +27,7 @@
 import software.amazon.awssdk.services.sns.endpoints.SnsEndpointProvider;
 import software.amazon.awssdk.utils.CompletableFutureUtils;
 import software.amazon.awssdk.utils.Logger;
+import software.amazon.awssdk.utils.Validate;
 
 /**
  * Utility class for determining both the regional endpoint that SNS certificates are expected to be hosted from, as well as the
@@ -46,6 +47,8 @@ public SnsHostProvider(Region region) {
 
     @SdkTestInternalApi
     SnsHostProvider(Region region, SnsEndpointProvider endpointProvider) {
+        Validate.notNull(region, "region must not be null");
+        Validate.notNull(endpointProvider, "endpointProvider must not be null");
         this.region = region;
         this.endpointProvider = endpointProvider;
     }

services-custom/sns-message-manager/src/test/java/software/amazon/awssdk/messagemanager/sns/internal/CertificateUrlValidatorTest.java

@@ -15,6 +15,7 @@
 
 package software.amazon.awssdk.messagemanager.sns.internal;
 
+import static org.assertj.core.api.Assertions.assertThatNoException;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 import java.net.URI;
@@ -24,6 +25,12 @@
 public class CertificateUrlValidatorTest {
     private static final String CERT_HOST = "my-test-service.amazonaws.com";
 
+    @Test
+    void validate_urlValid_succeeds() {
+        CertificateUrlValidator validator = new CertificateUrlValidator(CERT_HOST);
+        assertThatNoException().isThrownBy(() -> validator.validate(URI.create("https://" + CERT_HOST)));
+    }
+
     @Test
     void validate_urlNull_throws() {
         CertificateUrlValidator validator = new CertificateUrlValidator(CERT_HOST);

services-custom/sns-message-manager/src/test/java/software/amazon/awssdk/messagemanager/sns/internal/SnsHostProviderTest.java

@@ -16,6 +16,7 @@
 package software.amazon.awssdk.messagemanager.sns.internal;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
@@ -39,6 +40,17 @@ void signingCertCommonName_returnsCorrectNameForRegion(CommonNameTestCase tc) {
         assertThat(hostProvider.signingCertCommonName()).isEqualTo(tc.expectedCommonName);
     }
 
+    @Test
+    void ctor_regionNull_throws() {
+        assertThatThrownBy(() -> new SnsHostProvider(null)).hasMessage("region must not be null");
+    }
+
+    @Test
+    void ctor_endpointProviderNull_throws() {
+        assertThatThrownBy(() -> new SnsHostProvider(Region.US_WEST_2, null))
+            .hasMessage("endpointProvider must not be null");
+    }
+
     @Test
     void regionalEndpoint_delegatesToEndpointProvider() {
         SnsEndpointProvider mockProvider = mock(SnsEndpointProvider.class);