Fix additional properties handling in 3.1 spec

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

@@ -723,15 +723,17 @@ public Schema normalizeSchema(Schema schema, Set<Schema> visitedSchemas) {
         if (skipNormalization(schema, visitedSchemas)) {
             return schema;
         }
+
+        if (ModelUtils.isNullTypeSchema(openAPI, schema)) {
+            return schema;
+        }
+
         markSchemaAsVisited(schema, visitedSchemas);
 
         if (ModelUtils.isArraySchema(schema)) { // array
             Schema result = normalizeArraySchema(schema);
             normalizeSchema(result.getItems(), visitedSchemas);
             return result;
-        } else if (schema.getAdditionalProperties() instanceof Schema) { // map
-            normalizeMapSchema(schema);
-            normalizeSchema((Schema) schema.getAdditionalProperties(), visitedSchemas);
         } else if (ModelUtils.isOneOf(schema)) { // oneOf
             return normalizeOneOf(schema, visitedSchemas);
         } else if (ModelUtils.isAnyOf(schema)) { // anyOf
@@ -768,6 +770,9 @@ public Schema normalizeSchema(Schema schema, Set<Schema> visitedSchemas) {
             return schema;
         } else if (schema.getProperties() != null && !schema.getProperties().isEmpty()) {
             normalizeProperties(schema.getProperties(), visitedSchemas);
+        } else if (schema.getAdditionalProperties() instanceof Schema) { // map
+            normalizeMapSchema(schema);
+            normalizeSchema((Schema) schema.getAdditionalProperties(), visitedSchemas);
         } else if (schema instanceof BooleanSchema) {
             normalizeBooleanSchema(schema, visitedSchemas);
         } else if (schema instanceof IntegerSchema) {
@@ -1011,6 +1016,7 @@ protected Schema normalizeAnyOf(Schema schema, Set<Schema> visitedSchemas) {
         if (schema.getAnyOf() == null) {
             return schema;
         }
+
         for (int i = 0; i < schema.getAnyOf().size(); i++) {
             // normalize anyOf sub schemas one by one
             Object item = schema.getAnyOf().get(i);

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

@@ -953,6 +953,11 @@ public void testOpenAPINormalizerSimplifyOneOfAnyOf31Spec() {
         Schema schema21 = openAPI.getComponents().getSchemas().get("SingleAnyOfTest");
         assertEquals(schema21.getAnyOf().size(), 1);
 
+        Schema schema23 = openAPI.getComponents().getSchemas().get("PropertiesWithAnyOf");
+        assertEquals(((Schema) schema23.getProperties().get("anyof_nullable_string")).getAnyOf().size(), 2);
+        assertEquals(((Schema) schema23.getProperties().get("anyof_nullable_number")).getAnyOf().size(), 2);
+
+        // start the normalization
         Map<String, String> options = new HashMap<>();
         options.put("SIMPLIFY_ONEOF_ANYOF", "true");
         OpenAPINormalizer openAPINormalizer = new OpenAPINormalizer(openAPI, options);
@@ -1007,6 +1012,14 @@ public void testOpenAPINormalizerSimplifyOneOfAnyOf31Spec() {
         assertEquals(schema22.getAnyOf(), null);
         assertEquals(schema22.getTypes(), Set.of("string"));
         assertEquals(schema22.getEnum().size(), 2);
+
+        Schema schema24 = openAPI.getComponents().getSchemas().get("PropertiesWithAnyOf");
+        assertEquals(((Schema) schema24.getProperties().get("anyof_nullable_string")).getAnyOf(), null);
+        assertEquals(((Schema) schema24.getProperties().get("anyof_nullable_string")).getNullable(), true);
+        assertEquals(((Schema) schema24.getProperties().get("anyof_nullable_string")).getTypes().size(), 1);
+        assertEquals(((Schema) schema24.getProperties().get("anyof_nullable_number")).getAnyOf(), null);
+        assertEquals(((Schema) schema24.getProperties().get("anyof_nullable_number")).getNullable(), true);
+        assertEquals(((Schema) schema24.getProperties().get("anyof_nullable_number")).getTypes().size(), 1);
     }
 
     @Test

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

@@ -623,6 +623,47 @@ public void isNullTypeSchemaTest() {
         assertFalse(ModelUtils.isNullTypeSchema(openAPI, schema));
     }
 
+    @Test
+    public void isNullTypeSchemaTestWith31Spec() {
+        OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_1/null_schema_test.yaml");
+        Map<String, String> options = new HashMap<>();
+        Schema schema = openAPI.getComponents().getSchemas().get("AnyOfStringArrayOfString");
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, schema));
+
+        schema = openAPI.getComponents().getSchemas().get("IntegerRef");
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, schema));
+
+        schema = openAPI.getComponents().getSchemas().get("OneOfAnyType");
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, schema));
+
+        schema = openAPI.getComponents().getSchemas().get("AnyOfAnyType");
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, schema));
+
+        schema = openAPI.getComponents().getSchemas().get("Parent");
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, schema));
+        // the dummy property is a ref to integer
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, (Schema) schema.getProperties().get("dummy")));
+
+        schema = openAPI.getComponents().getSchemas().get("AnyOfTest");
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, schema));
+        // first element (getAnyOf().get(0)) is a string. no need to test
+        assertTrue(ModelUtils.isNullTypeSchema(openAPI, (Schema) schema.getAnyOf().get(1)));
+        assertTrue(ModelUtils.isNullTypeSchema(openAPI, (Schema) schema.getAnyOf().get(2)));
+        assertTrue(ModelUtils.isNullTypeSchema(openAPI, (Schema) schema.getAnyOf().get(3)));
+
+        schema = openAPI.getComponents().getSchemas().get("OneOfRef");
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, schema));
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, (Schema) schema.getOneOf().get(0)));
+
+        schema = openAPI.getComponents().getSchemas().get("OneOfMultiRef");
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, schema));
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, (Schema) schema.getOneOf().get(0)));
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, (Schema) schema.getOneOf().get(1)));
+
+        schema = openAPI.getComponents().getSchemas().get("JustDescription");
+        assertFalse(ModelUtils.isNullTypeSchema(openAPI, schema));
+    }
+
     @Test
     public void isUnsupportedSchemaTest() {
         OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_1/unsupported_schema_test.yaml");

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

@@ -0,0 +1,107 @@
+openapi: 3.1.0
+info:
+  version: 1.0.0
+  title: Example
+  license:
+    name: MIT
+servers:
+  - url: http://api.example.xyz/v1
+paths:
+  /person/display/{personId}:
+    get:
+      parameters:
+        - name: personId
+          in: path
+          required: true
+          description: The id of the person to retrieve
+          schema:
+            type: string
+      operationId: list
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AnyOfTest"
+components:
+  schemas:
+    AnyOfTest:
+      description: to test anyOf
+      anyOf:
+        - type: string
+        - type: 'null'
+        - type: null
+        - $ref: null
+    OneOfTest:
+      description: to test oneOf
+      oneOf:
+        - type: integer
+        - type: 'null'
+        - type: null
+        - $ref: null
+    OneOfTest2:
+      description: to test oneOf
+      oneOf:
+        - type: string
+        - type: 'null'
+    OneOfNullableTest:
+      description: to test oneOf nullable
+      oneOf:
+        - type: integer
+        - type: string
+        - $ref: null
+    Parent:
+      type: object
+      properties:
+        dummy:
+          $ref: '#/components/schemas/IntegerRef'
+        string_ref:
+          anyOf:
+            - $ref: '#/components/schemas/StringRef'
+    AnyOfStringArrayOfString:
+      anyOf:
+        - type: string
+        - type: array
+          items:
+            type: string
+    AnyOfAnyType:
+      anyOf:
+        - type: boolean
+        - type: array
+          items: {}
+        - type: object
+        - type: string
+        - type: number
+        - type: integer
+    AnyOfAnyTypeWithRef:
+      anyOf:
+        - type: boolean
+        - type: array
+          items: { }
+        - type: object
+        - type: string
+        - type: number
+        - $ref: '#/components/schemas/IntegerRef'
+    IntegerRef:
+      type: integer
+    StringRef:
+      type: string
+    OneOfAnyType:
+      oneOf:
+        - type: object
+        - type: boolean
+        - type: number
+        - type: string
+        - type: integer
+        - type: array
+          items: {}
+    OneOfRef:
+      oneOf:
+        - $ref: '#/components/schemas/IntegerRef'
+    OneOfMultiRef:
+      oneOf:
+        - $ref: '#/components/schemas/IntegerRef'
+        - $ref: '#/components/schemas/StringRef'
+    JustDescription:
+      description: A schema with just description

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

@@ -77,6 +77,18 @@ components:
           oneOf:
             - $ref: '#/components/schemas/Number'
             - $ref: '#/components/schemas/Number2'
+    PropertiesWithAnyOf:
+      additionalProperties: false
+      type: object
+      properties:
+        anyof_nullable_string:
+          anyOf:
+            - type: string
+            - type: null
+        anyof_nullable_number:
+          anyOf:
+            - type: number
+            - type: null
     Number:
       enum:
         - one