produce client-error for unspecified-properties (#166)

Co-authored-by: Michael Hoennig <michael@hoennig.de>
Reviewed-on: https://dev.hostsharing.net/hostsharing/hs.hsadmin.ng/pulls/166
Reviewed-by: Marc Sandlus <marc.sandlus@hostsharing.net>

src/main/java/net/hostsharing/hsadminng/config/JsonObjectMapperConfiguration.java

@@ -27,7 +27,8 @@ public class JsonObjectMapperConfiguration {
                 .modules(new JsonNullableModule(), new JavaTimeModule())
                 .featuresToEnable(
                         JsonParser.Feature.ALLOW_COMMENTS,
-                        DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS
+                        DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS,
+                        DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES
                 )
                 .featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
     }

src/main/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerEntityPatcher.java

@@ -25,6 +25,12 @@ class HsOfficePartnerEntityPatcher implements EntityPatcher<HsOfficePartnerPatch
     @Override
     public void apply(final HsOfficePartnerPatchResource resource) {
 
+        // HOWTO: allow properties from the GET request to be passed to PATCH, but only if unchanged.
+        //  These properties have to be specified in the OpenAPI PATCH resource specification,
+        //  ídeally with a comment in the description field, that the value mist be unchanged, if given at all.
+        ignoreUnchangedPropertyValue("uuid", resource.getUuid(), entity.getUuid());
+        ignoreUnchangedPropertyValue("partnerNumber", resource.getPartnerNumber(), entity.getPartnerNumber().toString());
+
         if (resource.getPartnerRel() != null) {
             new HsOfficeRelationPatcher(mapper, em, entity.getPartnerRel()).apply(resource.getPartnerRel());
         }

src/main/java/net/hostsharing/hsadminng/mapper/EntityPatcher.java

@@ -1,6 +1,19 @@
 package net.hostsharing.hsadminng.mapper;
 
+import org.openapitools.jackson.nullable.JsonNullable;
+
+import jakarta.validation.ValidationException;
+import java.util.Optional;
+
 public interface EntityPatcher<R> {
 
     void apply(R resource);
+
+    default <T> void ignoreUnchangedPropertyValue(final String propertyName, final JsonNullable<T> resourcePropertyValue, final T entityPropertyValue) {
+        Optional.ofNullable(resourcePropertyValue).ifPresent(value -> {
+            if (!value.get().equals(entityPropertyValue) ) {
+                throw new ValidationException(propertyName + " cannot be changed, either leave empty or leave unchanged as " + entityPropertyValue);
+            }
+        });
+    }
 }