Improve "allOf" support (#1169)

* Add test case which reproduces issue340

* Take the first $ref we find in the allOf-List

modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java

@@ -4215,12 +4215,12 @@ public class DefaultCodegen implements CodegenConfig {
 
     protected String getParentName(ComposedSchema composedSchema, Map<String, Schema> allSchemas) {
         if (composedSchema.getAllOf() != null && !composedSchema.getAllOf().isEmpty()) {
-            Schema schema = composedSchema.getAllOf().get(0);
-            String ref = schema.get$ref();
-            if (StringUtils.isBlank(ref)) {
-                return null;
+            for (Schema schema : composedSchema.getAllOf()) {
+                String ref = schema.get$ref();
+                if (!StringUtils.isBlank(ref)) {
+                    return ModelUtils.getSimpleRef(ref);
+                }
             }
-            return ModelUtils.getSimpleRef(ref);
         }
         return null;
     }

modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java

@@ -453,6 +453,16 @@ public class DefaultCodegenTest {
         verifyPersonDiscriminator(personModel.discriminator);
     }
 
+    @Test
+    public void testParentName() {
+        final OpenAPI openAPI = new OpenAPIParser().readLocation("src/test/resources/3_0/allOf.yaml", null, new ParseOptions()).getOpenAPI();
+        DefaultCodegen codegen = new DefaultCodegen();
+
+        Schema child = openAPI.getComponents().getSchemas().get("Child");
+        CodegenModel childModel = codegen.fromModel("Child", child, openAPI.getComponents().getSchemas());
+        Assert.assertEquals(childModel.parentSchema, "Person");
+    }
+
     @Test
     public void testCallbacks() {
         final OpenAPI openAPI = new OpenAPIParser().readLocation("src/test/resources/3_0/callbacks.yaml", null, new ParseOptions()).getOpenAPI();

modules/openapi-generator/src/test/resources/3_0/allOf.yaml

@@ -53,9 +53,9 @@ components:
     Child:
       description: A representation of a child
       allOf:
-      - $ref: '#/components/schemas/Person'
       - type: object
         properties:
           age:
             type: integer
             format: int32
+      - $ref: '#/components/schemas/Person'