Update inline model resolver to flatten responses (#19992)

* update inline model resolver flatten responses

* minor update

* minor update

* minor update

* minor update

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

@@ -107,6 +107,7 @@ public class InlineModelResolver {
 
         flattenPaths();
         flattenComponents();
+        flattenComponentResponses();
     }
 
     /**
@@ -568,6 +569,20 @@ public class InlineModelResolver {
         }
     }
 
+    /**
+     * Flatten inline models in the responses section in the components.
+     */
+    private void flattenComponentResponses() {
+        Map<String, ApiResponse> apiResponses = openAPI.getComponents().getResponses();
+        if (apiResponses == null) {
+            return;
+        }
+
+        for (Map.Entry<String, ApiResponse> entry : apiResponses.entrySet()) {
+            flattenContent(entry.getValue().getContent(), null);
+        }
+    }
+
     /**
      * Flattens properties of inline object schemas that belong to a composed schema into a
      * single flat list of properties. This is useful to generate a single or multiple

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

@@ -287,6 +287,7 @@ public class OpenAPINormalizer {
         normalizeInfo();
         normalizePaths();
         normalizeComponentsSchemas();
+        normalizeComponentsResponses();
     }
 
     /**
@@ -445,13 +446,20 @@ public class OpenAPINormalizer {
         }
 
         for (Map.Entry<String, ApiResponse> responsesEntry : responses.entrySet()) {
-            if (responsesEntry.getValue() == null) {
-                continue;
-            } else {
-                normalizeContent(ModelUtils.getReferencedApiResponse(openAPI, responsesEntry.getValue()).getContent());
-                normalizeHeaders(ModelUtils.getReferencedApiResponse(openAPI, responsesEntry.getValue()).getHeaders());
+            normalizeResponse(responsesEntry.getValue());
         }
     }
+
+    /**
+     * Normalizes schemas in ApiResponse
+     *
+     * @param apiResponse API response
+     */
+    private void normalizeResponse(ApiResponse apiResponse) {
+        if (apiResponse != null) {
+            normalizeContent(ModelUtils.getReferencedApiResponse(openAPI, apiResponse).getContent());
+            normalizeHeaders(ModelUtils.getReferencedApiResponse(openAPI, apiResponse).getHeaders());
+        }
     }
 
     /**
@@ -502,6 +510,20 @@ public class OpenAPINormalizer {
         }
     }
 
+    /**
+     * Normalizes schemas in component's responses.
+     */
+    private void normalizeComponentsResponses() {
+        Map<String, ApiResponse> apiResponses = openAPI.getComponents().getResponses();
+        if (apiResponses == null) {
+            return;
+        }
+
+           for (Map.Entry<String, ApiResponse> entry : apiResponses.entrySet()) {
+            normalizeResponse(entry.getValue());
+        }
+    }
+
     /**
      * Auto fix a self referencing schema using any type to replace the self-referencing sub-item.
      *
@@ -993,7 +1015,6 @@ public class OpenAPINormalizer {
     }
 
 
-
     /**
      * If the schema is oneOf and the sub-schemas is null, set `nullable: true`
      * instead.
@@ -1113,6 +1134,7 @@ public class OpenAPINormalizer {
         schema.setNullable(true);
         return schema;
     }
+
     /**
      * Set nullable to true in map if needed.
      *

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

@@ -352,6 +352,14 @@ public class InlineModelResolverTest {
         assertTrue(user.getProperties().get("city") instanceof StringSchema);
     }
 
+    @Test
+    public void resolveComponentsResponses() {
+        OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_0/inline_model_resolver.yaml");
+        new InlineModelResolver().flatten(openAPI);
+        ApiResponse apiResponse = openAPI.getComponents().getResponses().get("JustAnotherResponse");
+        assertEquals(apiResponse.getContent().get("application/json").getSchema().get$ref(), "#/components/schemas/inline_object");
+    }
+
     @Test
     public void resolveRequestBodyInvalidRef() {
         OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_0/invalid_ref_request_body.yaml");

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

@@ -16,10 +16,12 @@
 
 package org.openapitools.codegen;
 
+import io.swagger.annotations.Api;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.PathItem;
 import io.swagger.v3.oas.models.media.*;
 
+import io.swagger.v3.oas.models.responses.ApiResponse;
 import org.openapitools.codegen.utils.ModelUtils;
 import org.testng.annotations.Test;
 
@@ -794,4 +796,22 @@ public class OpenAPINormalizerTest {
         assertEquals(((Schema) schema2.getProperties().get("property2")).getAllOf(), null);
         assertEquals(((Schema) schema2.getProperties().get("property2")).getAllOf(), null);
     }
+
+    @Test
+    public void testOpenAPINormalizerComponentsResponses31Spec() {
+        OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_1/common-parameters.yaml");
+        ApiResponse apiResponse = openAPI.getComponents().getResponses().get("JustAnotherResponse");
+        assertEquals(((Schema) apiResponse.getContent().get("application/json").getSchema().getProperties().get("uuid")).getType(), null);
+        assertEquals(((Schema) apiResponse.getContent().get("application/json").getSchema().getProperties().get("label")).getType(), null);
+
+        Map<String, String> inputRules = Map.of(
+                "NORMALIZE_31SPEC", "true"
+        );
+        OpenAPINormalizer openAPINormalizer = new OpenAPINormalizer(openAPI, inputRules);
+        openAPINormalizer.normalize();
+
+        ApiResponse apiResponse2 = openAPI.getComponents().getResponses().get("JustAnotherResponse");
+        assertEquals(((Schema) apiResponse2.getContent().get("application/json").getSchema().getProperties().get("uuid")).getType(), "integer");
+        assertEquals(((Schema) apiResponse2.getContent().get("application/json").getSchema().getProperties().get("label")).getType(), "string");
+    }
 }

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

@@ -455,6 +455,18 @@ paths:
                           type: string
 components:
   requestBodies: {}
+  responses:
+    JustAnotherResponse:
+      description: just another response
+      content:
+        application/json:
+          schema:
+            type: object
+            properties:
+              uuid:
+                type: integer
+              label:
+                type: string
   schemas:
     Users:
       type: array

modules/openapi-generator/src/test/resources/3_1/common-parameters.yaml

@@ -76,6 +76,18 @@ paths:
       security:
         - api_key: []
 components:
+  responses:
+    JustAnotherResponse:
+      description: JustAnotherResponse
+      content:
+        application/json:
+          schema:
+            type: object
+            properties:
+              uuid:
+                type: integer
+              label:
+                type: string
   requestBodies:
     Pet:
       content: