Update inline model resolver to flatten responses (OpenAPITools#19992)

* update inline model resolver flatten responses

* minor update

* minor update

* minor update

* minor update

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

@@ -4774,7 +4774,7 @@ public CodegenOperation fromOperation(String path,
         op.hasRequiredParams = op.requiredParams.size() > 0;
 
         // check if the operation has only a single parameter
-       op.hasSingleParam = op.allParams.size() == 1;
+        op.hasSingleParam = op.allParams.size() == 1;
 
         // set Restful Flag
         op.isRestfulShow = op.isRestfulShow();
@@ -5724,7 +5724,7 @@ public void addOperationToGroup(String tag, String resourcePath, Operation opera
         // check for operationId uniqueness
         String uniqueName = co.operationId;
         int counter = seenOperationIds.getOrDefault(uniqueName, 0);
-        while(seenOperationIds.containsKey(uniqueName)) {
+        while (seenOperationIds.containsKey(uniqueName)) {
             uniqueName = co.operationId + "_" + counter;
             counter++;
         }
@@ -6120,7 +6120,7 @@ private String uniqueCaseInsensitiveString(String value, Map<String, String> see
             return seenValues.get(value);
         }
 
-        Optional<Entry<String,String>> foundEntry = seenValues.entrySet().stream().filter(v -> v.getValue().toLowerCase(Locale.ROOT).equals(value.toLowerCase(Locale.ROOT))).findAny();
+        Optional<Entry<String, String>> foundEntry = seenValues.entrySet().stream().filter(v -> v.getValue().toLowerCase(Locale.ROOT).equals(value.toLowerCase(Locale.ROOT))).findAny();
         if (foundEntry.isPresent()) {
             int counter = 0;
             String uniqueValue = value + "_" + counter;
@@ -8181,7 +8181,7 @@ protected boolean executePostProcessor(String[] commandArr) {
             int exitValue = p.exitValue();
             if (exitValue != 0) {
                 try (InputStreamReader inputStreamReader = new InputStreamReader(p.getErrorStream(), StandardCharsets.UTF_8);
-                    BufferedReader br = new BufferedReader(inputStreamReader)) {
+                BufferedReader br = new BufferedReader(inputStreamReader)) {
                     StringBuilder sb = new StringBuilder();
                     String line;
                     while ((line = br.readLine()) != null) {

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

@@ -107,6 +107,7 @@ void flatten(OpenAPI openAPI) {
 
         flattenPaths();
         flattenComponents();
+        flattenComponentResponses();
     }
 
     /**
@@ -352,7 +353,7 @@ private void gatherInlineModels(Schema schema, String modelPrefix) {
             }
 
             if (items == null) {
-                LOGGER.debug("prefixItems in array schema is not supported at the moment: {}",  schema.toString());
+                LOGGER.debug("prefixItems in array schema is not supported at the moment: {}", schema.toString());
                 return;
             }
             String schemaName = resolveModelName(items.getTitle(), modelPrefix + this.inlineSchemaOptions.get("ARRAY_ITEM_SUFFIX"));
@@ -568,6 +569,20 @@ private void flattenResponses(String modelName, Operation operation) {
         }
     }
 
+    /**
+     * 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 @@ void normalize() {
         normalizeInfo();
         normalizePaths();
         normalizeComponentsSchemas();
+        normalizeComponentsResponses();
     }
 
     /**
@@ -445,12 +446,19 @@ private void normalizeResponses(Operation operation) {
         }
 
         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());
         }
     }
 
@@ -502,11 +510,25 @@ private void normalizeComponentsSchemas() {
         }
     }
 
+    /**
+     * 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.
      *
-     * @param name           Schema name
-     * @param schema         Schema
+     * @param name   Schema name
+     * @param schema Schema
      */
     public void fixSelfReferenceSchema(String name, Schema schema) {
         if (ModelUtils.isArraySchema(schema)) {
@@ -993,7 +1015,6 @@ private Schema processSimplifyAnyOfStringAndEnumString(Schema schema) {
     }
 
 
-
     /**
      * If the schema is oneOf and the sub-schemas is null, set `nullable: true`
      * instead.
@@ -1012,7 +1033,7 @@ private Schema processSimplifyOneOf(Schema schema) {
             // simplify any type with 6 sub-schemas (string, integer, etc) in oneOf
             if (oneOfSchemas.size() == 6) {
                 TreeSet<String> ts = new TreeSet<>();
-                for (Schema s: oneOfSchemas) {
+                for (Schema s : oneOfSchemas) {
                     s = ModelUtils.getReferencedSchema(openAPI, s);
                     String type = ModelUtils.getType(s);
                     if (type == null) {
@@ -1113,6 +1134,7 @@ private Schema setNullable(Schema schema) {
         schema.setNullable(true);
         return schema;
     }
+
     /**
      * Set nullable to true in map if needed.
      *
@@ -1148,7 +1170,7 @@ private Schema processSimplifyAnyOf(Schema schema) {
             // simplify any type with 6 sub-schemas (string, integer, etc) in anyOf
             if (anyOfSchemas.size() == 6) {
                 TreeSet<String> ts = new TreeSet<>();
-                for (Schema s: anyOfSchemas) {
+                for (Schema s : anyOfSchemas) {
                     s = ModelUtils.getReferencedSchema(openAPI, s);
                     String type = ModelUtils.getType(s);
                     if (type == null) {

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

@@ -352,6 +352,14 @@ public void resolveInlineArraySchemaWithTitle() {
         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$ref(), "#/components/schemas/inline_object");
+    }
+
     @Test
     public void resolveRequestBodyInvalidRef() {
         OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_0/invalid_ref_request_body.yaml");
@@ -1043,7 +1051,7 @@ public void testInlineSchemaNameMapping() {
     public void testInlineSchemaOptions() {
         OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_0/inline_model_resolver.yaml");
         InlineModelResolver resolver = new InlineModelResolver();
-        Map<String, String> inlineSchemaOptions= new HashMap<>();
+        Map<String, String> inlineSchemaOptions = new HashMap<>();
         inlineSchemaOptions.put("ARRAY_ITEM_SUFFIX", "_something");
         resolver.setInlineSchemaOptions(inlineSchemaOptions);
         resolver.flatten(openAPI);
@@ -1135,7 +1143,7 @@ public void testNestedAnyOf() {
     public void resolveOperationInlineEnum() {
         OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_0/inline_model_resolver.yaml");
         Parameter parameter = openAPI.getPaths().get("/resolve_parameter_inline_enum").getGet().getParameters().get(0);
-        assertNull(((ArraySchema) parameter.getSchema()).getItems().get$ref() );
+        assertNull(((ArraySchema) parameter.getSchema()).getItems().get$ref());
 
         InlineModelResolver resolver = new InlineModelResolver();
         Map<String, String> inlineSchemaOptions = new HashMap<>();
@@ -1145,7 +1153,7 @@ public void resolveOperationInlineEnum() {
 
         Parameter parameter2 = openAPI.getPaths().get("/resolve_parameter_inline_enum").getGet().getParameters().get(0);
         assertEquals("#/components/schemas/resolveParameterInlineEnum_status_inline_enum_parameter_inner",
-                ((ArraySchema) parameter2.getSchema()).getItems().get$ref() );
+                ((ArraySchema) parameter2.getSchema()).getItems().get$ref());
 
     }
 

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;
 
@@ -549,7 +551,7 @@ public void testSetPrimitiveTypesToNullable() {
     }
 
     @Test
-    public void testOpenAPINormalizerSimplifyOneOfAnyOf31SpecForIssue18184  () {
+    public void testOpenAPINormalizerSimplifyOneOfAnyOf31SpecForIssue18184() {
         // to test the rule SIMPLIFY_ONEOF_ANYOF in 3.1 spec
         OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_1/issue_18184.yaml");
         // test spec contains anyOf with a ref to enum and another scheme type is null
@@ -794,4 +796,22 @@ public void testOpenAPINormalizerProcessingAllOfSchema31Spec() {
         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: