Add testSameTypeResponseSchemaDIff based on issue OpenAPITools#192.

Author: M0dM

core/src/test/java/org/openapitools/openapidiff/core/RequestDiffTest.java

@@ -1,8 +1,10 @@
 package org.openapitools.openapidiff.core;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.openapitools.openapidiff.core.TestUtils.assertOpenApiChangedEndpoints;
 
 import org.junit.jupiter.api.Test;
+import org.openapitools.openapidiff.core.model.ChangedOpenApi;
 
 public class RequestDiffTest {
   private final String OPENAPI_DOC1 = "request_diff_1.yaml";
@@ -12,4 +14,13 @@ public class RequestDiffTest {
   public void testDiffDifferent() {
     assertOpenApiChangedEndpoints(OPENAPI_DOC1, OPENAPI_DOC2);
   }
+
+  @Test
+  public void testSameTypeResponseSchemaDIff() {
+    ChangedOpenApi changedOpenApi =
+        OpenApiCompare.fromLocations(
+            "response_schema_simple_object_type.yaml",
+            "response_schema_simple_object_type_with_alloff.yaml");
+    assertThat(changedOpenApi.isCompatible()).isTrue();
+  }
 }

core/src/test/resources/response_schema_simple_object_type.yaml

@@ -0,0 +1,27 @@
+openapi: "3.0.0"
+info:
+  title: Sample API
+  description: API description in Markdown.
+  version: 1.0.0
+servers: []
+paths:
+  /test:
+    get:
+      summary: Your GET endpoint
+      tags: []
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/working'
+components:
+  schemas:
+    working:
+      type: object
+      properties:
+        foo:
+          type: string
+        bar:
+          type: integer

core/src/test/resources/response_schema_simple_object_type_with_alloff.yaml

@@ -0,0 +1,33 @@
+openapi: 3.0.0
+info:
+  title: Sample API
+  description: API description in Markdown.
+  version: 1.1.0
+servers: []
+paths:
+  /test:
+    get:
+      summary: Your GET endpoint
+      tags: []
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/working'
+      operationId: get-test
+components:
+  schemas:
+    working:
+      allOf:
+        - type: object
+          properties:
+            foo:
+              type: string
+        - $ref: '#/components/schemas/bar'
+    bar:
+      type: object
+      properties:
+        bar:
+          type: integer