Handle recursive refs in ComposedSchema (allOf/oneOf/anyOf)

Author: maksim-kosolapov

core/src/main/java/org/openapitools/openapidiff/core/compare/SchemaDiff.java

@@ -27,8 +27,11 @@
 import org.openapitools.openapidiff.core.model.deferred.RecursiveSchemaSet;
 import org.openapitools.openapidiff.core.utils.RefPointer;
 import org.openapitools.openapidiff.core.utils.RefType;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class SchemaDiff {
+  private static final Logger logger = LoggerFactory.getLogger(SchemaDiff.class);
 
   private static final RefPointer<Schema<?>> refPointer = new RefPointer<>(RefType.SCHEMAS);
   private static final Map<Class<? extends Schema>, Class<? extends SchemaDiffResult>>
@@ -96,7 +99,14 @@ protected static Schema<?> resolveComposedSchema(
             updatedVisitedRefs.add(composed.get$ref());
             composed = refPointer.resolveRef(components, composed, composed.get$ref());
             composed = resolveComposedSchema(components, composed, updatedVisitedRefs);
-            schema = addSchema(schema, composed);
+            if (composed.getProperties() != null
+                && composed.getProperties().containsValue(composedSchema)) {
+              logger.warn(
+                  "Circular reference detected in composed (allOf/oneOf/anyOf) schema: {}",
+                  composed.get$ref());
+            } else {
+              addSchema(schema, composed);
+            }
           }
         }
         composedSchema.setAllOf(null);

core/src/main/java/org/openapitools/openapidiff/core/model/deferred/RecursiveSchemaSet.java

@@ -13,6 +13,6 @@ public boolean contains(CacheKey key) {
 
   public void put(CacheKey key) {
     leftKeys.add(key.getLeft());
-    leftKeys.add(key.getRight());
+    rightKeys.add(key.getRight());
   }
 }

core/src/test/resources/recursive_model_1.yaml

@@ -25,6 +25,17 @@ components:
           type: string
         message2:
           type: string
+        recursiveDirect:
+          $ref: '#/components/schemas/B'
+        recursiveAllOf:
+          allOf:
+            - $ref: '#/components/schemas/B'
+        recursiveOneOf:
+          oneOf:
+            - $ref: '#/components/schemas/B'
+        recursiveAnyOf:
+          anyOf:
+            - $ref: '#/components/schemas/B'
         details:
           type: array
           items: