Better support of inline allOf/anyOf/oneOf schemas (#14887)

* better support of inilne allof schemas

* add test file

* better handling of anyof, oneof inline schemas

* update samples

* add tests for nested anyof

* better code format

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

@@ -224,7 +224,7 @@ private boolean isModelNeeded(Schema schema, Set<Schema> visitedSchemas) {
             }
 
             if (m.getAllOf() != null && !m.getAllOf().isEmpty()) {
-                // check to ensure at least of the allOf item is model
+                // check to ensure at least one of the allOf item is model
                 for (Schema inner : m.getAllOf()) {
                     if (isModelNeeded(ModelUtils.getReferencedSchema(openAPI, inner), visitedSchemas)) {
                         return true;
@@ -385,6 +385,7 @@ private void gatherInlineModels(Schema schema, String modelPrefix) {
                     }
                 }
                 m.setAnyOf(newAnyOf);
+
             }
             if (m.getOneOf() != null) {
                 List<Schema> newOneOf = new ArrayList<Schema>();
@@ -541,15 +542,15 @@ private void flattenResponses(String modelName, Operation operation) {
      * allOf:
      * - $ref: '#/components/schemas/Animal'
      * - type: object
-     * properties:
-     * name:
-     * type: string
-     * age:
-     * type: string
+     *   properties:
+     *     name:
+     *       type: string
+     *     age:
+     *       type: string
      * - type: object
-     * properties:
-     * breed:
-     * type: string
+     *   properties:
+     *     breed:
+     *       type: string
      *
      * @param key      a unique name ofr the composed schema.
      * @param children the list of nested schemas within a composed schema (allOf, anyOf, oneOf).
@@ -577,6 +578,8 @@ private void flattenComposedChildren(String key, List<Schema> children) {
                 // instead of inline.
                 String innerModelName = resolveModelName(component.getTitle(), key);
                 Schema innerModel = modelFromProperty(openAPI, component, innerModelName);
+                // Recurse to create $refs for inner models
+                gatherInlineModels(innerModel, innerModelName);
                 String existing = matchGenerated(innerModel);
                 if (existing == null) {
                     innerModelName = addSchemas(innerModelName, innerModel);
@@ -604,13 +607,17 @@ private void flattenComponents() {
         List<String> modelNames = new ArrayList<String>(models.keySet());
         for (String modelName : modelNames) {
             Schema model = models.get(modelName);
-            if (ModelUtils.isComposedSchema(model)) {
+            if (ModelUtils.isAnyOf(model)) { // contains anyOf only
+                gatherInlineModels(model, modelName);
+            } else if (ModelUtils.isOneOf(model)) { // contains oneOf only
+                gatherInlineModels(model, modelName);
+            } else if (ModelUtils.isComposedSchema(model)) {
                 ComposedSchema m = (ComposedSchema) model;
                 // inline child schemas
                 flattenComposedChildren(modelName + "_allOf", m.getAllOf());
                 flattenComposedChildren(modelName + "_anyOf", m.getAnyOf());
                 flattenComposedChildren(modelName + "_oneOf", m.getOneOf());
-            } else if (model instanceof Schema) {
+            } else {
                 gatherInlineModels(model, modelName);
             }
         }

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

@@ -1885,6 +1885,70 @@ public static boolean hasAllOf(Schema schema) {
         return false;
     }
 
+    /**
+     * Returns true if the schema contains oneOf but
+     * no properties/allOf/anyOf defined.
+     *
+     * @param schema the schema
+     * @return true if the schema contains oneOf but no properties/allOf/anyOf defined.
+     */
+    public static boolean isOneOf(Schema schema) {
+        if (hasOneOf(schema) && (schema.getProperties() == null || schema.getProperties().isEmpty()) &&
+                (schema.getAllOf() == null || schema.getAllOf().isEmpty()) &&
+                (schema.getAnyOf() == null || schema.getAnyOf().isEmpty())) {
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Returns true if the schema contains oneOf and may or may not have
+     * properties/allOf/anyOf defined.
+     *
+     * @param schema the schema
+     * @return true if allOf is not empty
+     */
+    public static boolean hasOneOf(Schema schema) {
+        if (schema.getOneOf() != null && !schema.getOneOf().isEmpty()) {
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Returns true if the schema contains anyOf but
+     * no properties/allOf/anyOf defined.
+     *
+     * @param schema the schema
+     * @return true if the schema contains oneOf but no properties/allOf/anyOf defined.
+     */
+    public static boolean isAnyOf(Schema schema) {
+        if (hasAnyOf(schema) && (schema.getProperties() == null || schema.getProperties().isEmpty()) &&
+                (schema.getAllOf() == null || schema.getAllOf().isEmpty()) &&
+                (schema.getOneOf() == null || schema.getOneOf().isEmpty())) {
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Returns true if the schema contains anyOf and may or may not have
+     * properties/allOf/oneOf defined.
+     *
+     * @param schema the schema
+     * @return true if anyOf is not empty
+     */
+    public static boolean hasAnyOf(Schema schema) {
+        if (schema.getAnyOf() != null && !schema.getAnyOf().isEmpty()) {
+            return true;
+        }
+
+        return false;
+    }
+
     /**
      * Returns true if any of the common attributes of the schema (e.g. readOnly, default, maximum, etc) is defined.
      *

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

@@ -1103,4 +1103,29 @@ public void resolveInlineRequestBodyAllOf() {
         //RequestBody referencedRequestBody = ModelUtils.getReferencedRequestBody(openAPI, requestBodyReference);
         //assertTrue(referencedRequestBody.getRequired());
     }
+
+    @Test
+    public void testInlineSchemaAllOfPropertyOfOneOf() {
+        OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_0/inline_model_allof_propertyof_oneof.yaml");
+        InlineModelResolver resolver = new InlineModelResolver();
+        resolver.flatten(openAPI);
+
+        Schema schema = openAPI.getComponents().getSchemas().get("Order_allOf_inline_oneof");
+        assertEquals(((Schema) schema.getOneOf().get(0)).get$ref(), "#/components/schemas/Tag");
+        assertEquals(((Schema) schema.getOneOf().get(1)).get$ref(), "#/components/schemas/Filter");
+
+        Schema schema2 = openAPI.getComponents().getSchemas().get("Order_allOf_inline_model");
+        assertTrue(schema2.getProperties().get("something") instanceof StringSchema);
+    }
+
+    @Test
+    public void testNestedAnyOf() {
+        OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_0/nested_anyof.yaml");
+        InlineModelResolver resolver = new InlineModelResolver();
+        resolver.flatten(openAPI);
+
+        Schema schema = openAPI.getComponents().getSchemas().get("SomeData_anyOf");
+        assertTrue((Schema) schema.getAnyOf().get(0) instanceof StringSchema);
+        assertTrue((Schema) schema.getAnyOf().get(1) instanceof IntegerSchema);
+    }
 }

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

@@ -0,0 +1,56 @@
+openapi: 3.0.1
+info:
+  title: ping test
+  version: '1.0'
+servers:
+  - url: 'http://localhost:8000/'
+paths:
+  /ping:
+    get:
+      operationId: pingGet
+      responses:
+        '201':
+          description: OK
+components:
+  schemas:
+    Order:
+      title: Pet Order
+      description: An order for a pets from the pet store
+      allOf:
+        - $ref: "#/components/schemas/Tag"
+        - type: object
+          properties:
+            length:
+              type: integer
+              format: int64
+            shipDate:
+              type: string
+              format: date-time
+            inline_oneof:
+              oneOf:
+                - $ref: "#/components/schemas/Tag"
+                - $ref: "#/components/schemas/Filter"
+            inline_model:
+              properties:
+                something:
+                  type: string
+    Tag:
+      title: Pet Tag
+      description: A tag for a pet
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+    Filter:
+      title: Pet Tag
+      description: A tag for a pet
+      type: object
+      properties:
+        fid:
+          type: integer
+          format: int64
+        fname:
+          type: string

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

@@ -0,0 +1,16 @@
+openapi: 3.0.0
+info:
+  version: '1.0.0'
+  title: 'Problem example with nested anyOf'
+paths: {}
+components:
+  schemas:
+    NullOne:
+      enum:
+        - null
+    SomeData:
+      anyOf:
+      - anyOf:
+          - type: string
+          - type: integer
+      - $ref: '#/components/schemas/NullOne'

samples/server/petstore/rust-server/output/openapi-v3/.openapi-generator/FILES

@@ -9,14 +9,12 @@ docs/AnotherXmlInner.md
 docs/AnotherXmlObject.md
 docs/AnyOfGet202Response.md
 docs/AnyOfObject.md
-docs/AnyOfObjectAnyOf.md
 docs/AnyOfProperty.md
 docs/DuplicateXmlObject.md
 docs/EnumWithStarObject.md
 docs/Err.md
 docs/Error.md
 docs/Model12345AnyOfObject.md
-docs/Model12345AnyOfObjectAnyOf.md
 docs/MultigetGet201Response.md
 docs/MyId.md
 docs/MyIdList.md

samples/server/petstore/rust-server/output/openapi-v3/README.md

@@ -155,14 +155,12 @@ Method | HTTP request | Description
  - [AnotherXmlObject](docs/AnotherXmlObject.md)
  - [AnyOfGet202Response](docs/AnyOfGet202Response.md)
  - [AnyOfObject](docs/AnyOfObject.md)
- - [AnyOfObjectAnyOf](docs/AnyOfObjectAnyOf.md)
  - [AnyOfProperty](docs/AnyOfProperty.md)
  - [DuplicateXmlObject](docs/DuplicateXmlObject.md)
  - [EnumWithStarObject](docs/EnumWithStarObject.md)
  - [Err](docs/Err.md)
  - [Error](docs/Error.md)
  - [Model12345AnyOfObject](docs/Model12345AnyOfObject.md)
- - [Model12345AnyOfObjectAnyOf](docs/Model12345AnyOfObjectAnyOf.md)
  - [MultigetGet201Response](docs/MultigetGet201Response.md)
  - [MyId](docs/MyId.md)
  - [MyIdList](docs/MyIdList.md)

samples/server/petstore/rust-server/output/openapi-v3/api/openapi.yaml

@@ -478,13 +478,20 @@ components:
       - requiredAnyOf
     AnyOfObject:
       anyOf:
-      - $ref: '#/components/schemas/AnyOfObject_anyOf'
+      - enum:
+        - FOO
+        - BAR
+        type: string
       - description: Alternate option
         type: string
       description: Test a model containing an anyOf
     "12345AnyOfObject":
       anyOf:
-      - $ref: '#/components/schemas/_12345AnyOfObject_anyOf'
+      - enum:
+        - FOO
+        - BAR
+        - '*'
+        type: string
       - description: Alternate option
         type: string
       description: Test a model containing an anyOf that starts with a number
@@ -678,19 +685,6 @@ components:
       anyOf:
       - $ref: '#/components/schemas/StringObject'
       - $ref: '#/components/schemas/UuidObject'
-    AnyOfObject_anyOf:
-      enum:
-      - FOO
-      - BAR
-      type: string
-      example: null
-    _12345AnyOfObject_anyOf:
-      enum:
-      - FOO
-      - BAR
-      - '*'
-      type: string
-      example: null
   securitySchemes:
     authScheme:
       flows: