From 33686267f9deeeca24200c49747868880f9c7808 Mon Sep 17 00:00:00 2001
From: Holger Knoche <hkn@informatik.uni-kiel.de>
Date: Wed, 27 Mar 2024 08:09:29 +0100
Subject: [PATCH] Added support for unmapped exceptions

---
 .../json/consumer/ConsumerOperationProxy.java | 11 +++++-
 .../apievolution/json/JsonMappingTest.java    | 37 +++++++++++++++++++
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/gutta-apievolution-json/src/main/java/gutta/apievolution/json/consumer/ConsumerOperationProxy.java b/gutta-apievolution-json/src/main/java/gutta/apievolution/json/consumer/ConsumerOperationProxy.java
index fb456d4..0a27b12 100644
--- a/gutta-apievolution-json/src/main/java/gutta/apievolution/json/consumer/ConsumerOperationProxy.java
+++ b/gutta-apievolution-json/src/main/java/gutta/apievolution/json/consumer/ConsumerOperationProxy.java
@@ -166,8 +166,15 @@ public R invokeOperation(P parameterObject, OnUnrepresentableValue<?> onUnrepres
                 String exceptionTypeName = determineSpecificTypeId(responseNode).orElseThrow(NoSuchElementException::new);
                 Class<?> exceptionTypeRepresentation = this.exceptionTypeMap.get(exceptionTypeName);
                 
-                MappedExceptionData exceptionData = (MappedExceptionData) objectMapper.treeToValue(responseNode, exceptionTypeRepresentation);
-                throw exceptionData.createMappedException();
+                if (exceptionTypeRepresentation != null) {
+                    // If the exception type is mapped, create the appropriate exception
+                    MappedExceptionData exceptionData = (MappedExceptionData) objectMapper.treeToValue(responseNode, exceptionTypeRepresentation);
+                    throw exceptionData.createMappedException();
+                } else {
+                    // Otherwise, treat the exception as an unrepresentable value
+                    JsonNode resultNode = onUnrepresentableValue.throwExceptionOrReturnDefaultNode();
+                    return objectMapper.treeToValue(resultNode, this.resultTypeRepresentation);
+                }
             } else {
                 // Otherwise, return the value
                 return objectMapper.treeToValue(responseNode, this.resultTypeRepresentation);
diff --git a/gutta-apievolution-json/src/test/java/gutta/apievolution/json/JsonMappingTest.java b/gutta-apievolution-json/src/test/java/gutta/apievolution/json/JsonMappingTest.java
index ac94bf1..f55fe0b 100644
--- a/gutta-apievolution-json/src/test/java/gutta/apievolution/json/JsonMappingTest.java
+++ b/gutta-apievolution-json/src/test/java/gutta/apievolution/json/JsonMappingTest.java
@@ -16,6 +16,7 @@
 import gutta.apievolution.json.consumer.ConsumerSuperType;
 import gutta.apievolution.json.consumer.ConsumerTestException;
 import gutta.apievolution.json.consumer.ConsumerTestExceptionData;
+import gutta.apievolution.json.consumer.UnrepresentableValueException;
 import gutta.apievolution.json.provider.MappableProviderTestException;
 import gutta.apievolution.json.provider.ProviderEnum;
 import gutta.apievolution.json.provider.ProviderMonoToPolySubTypeA;
@@ -175,6 +176,18 @@ void embeddedMonoToPolyTypeMapping() {
         assertNotSame(parameter, result);
         assertEquals(parameter, result);
     }
+    
+    /**
+     * Test case: The provider throws an exception, but the consumer does not expect one. This results in an unrepresentable value.
+     */
+    @Test
+    void providerThrowsExceptionButConsumerDoesNotExpectOne() {
+        OpWithUnmappedExceptionProviderProxy providerProxy = new OpWithUnmappedExceptionProviderProxy();
+        RequestRouter requestRouter = new SimpleJsonRequestRouter(providerProxy);
+   
+        OpWithUnmappedExceptionConsumerProxy consumerProxy = new OpWithUnmappedExceptionConsumerProxy(requestRouter);
+        assertThrows(UnrepresentableValueException.class, () -> consumerProxy.invokeOperation(new ConsumerParameter()));
+    }
 
     private abstract static class ConsumerOperationProxyTemplate<P, R> extends ConsumerOperationProxy<P, R> {
                 
@@ -308,6 +321,30 @@ protected ProviderResult invokeOperation(ProviderParameter parameter) {
         
     }
     
+    private static class OpWithUnmappedExceptionConsumerProxy extends ConsumerOperationProxyTemplate<ConsumerParameter, ConsumerResult> {
+        
+        public OpWithUnmappedExceptionConsumerProxy(RequestRouter router) {
+            super("opWithUnmappedException", "ConsumerParameter", "ConsumerResult", ConsumerResult.class, Collections.emptySet(), router);
+        }
+        
+    }
+    
+    private static class OpWithUnmappedExceptionProviderProxy extends ProviderOperationProxyTemplate<ProviderParameter, ProviderResult> {
+        
+        public OpWithUnmappedExceptionProviderProxy() {
+            super("opWithUnmappedException", "ProviderParameter" , "ProviderResult", ProviderParameter.class);
+        }
+        
+        @Override
+        protected ProviderResult invokeOperation(ProviderParameter parameter) {
+            ProviderTestException exceptionData = new ProviderTestException();
+            exceptionData.setExceptionField(1234);
+            
+            throw new MappableProviderTestException(exceptionData);
+        }
+        
+    }
+    
     private static class MonoToPolyMappingConsumerProxy extends ConsumerOperationProxyTemplate<ConsumerMonoToPolyType, ConsumerMonoToPolyType> {
         
         public MonoToPolyMappingConsumerProxy(RequestRouter router) {