better handling of allOf with a single type

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

@@ -128,7 +128,14 @@ private boolean isModelNeeded(Schema schema) {
             // allOf, anyOf, oneOf
             ComposedSchema m = (ComposedSchema) schema;
             if (m.getAllOf() != null && !m.getAllOf().isEmpty()) {
-                return true;
+                // check to ensure at least of the allOf item is model
+                for (Schema inner : m.getAllOf()) {
+                    if (isModelNeeded(inner)) {
+                        return true;
+                    }
+                }
+                // allOf items are all non-model (e.g. type: string) only
+                return false;
             }
             if (m.getAnyOf() != null && !m.getAnyOf().isEmpty()) {
                 return true;
@@ -176,6 +183,10 @@ private void gatherInlineModels(Schema schema, String modelPrefix) {
                         //Schema refSchema = this.makeSchemaResolve(modelPrefix, StringUtils.camelize(propName), prop);
                         Schema refSchema = this.makeSchemaResolve(modelPrefix, "_" + propName, prop);
                         props.put(propName, refSchema);
+                    } else if (prop instanceof ComposedSchema && ((ComposedSchema)prop).getAllOf().size() == 1) {
+                        // allOf with only 1 type
+                        LOGGER.info("allOf schema used by the property `{}` replaced by its only item (a type).", propName);
+                        props.put(propName, ((ComposedSchema)prop).getAllOf().get(0));
                     }
                 }
             }
@@ -227,17 +238,30 @@ private void gatherInlineModels(Schema schema, String modelPrefix) {
             ComposedSchema m = (ComposedSchema) schema;
             if (m.getAllOf() != null) {
                 List<Schema> newAllOf = new ArrayList<Schema>();
+                boolean atLeastOneModel = false;
                 for (Schema inner : m.getAllOf()) {
                     // Recurse to create $refs for inner models
                     gatherInlineModels(inner, modelPrefix + "_allOf");
                     if (isModelNeeded(inner)) {
                         Schema refSchema = this.makeSchemaResolve(modelPrefix, "_allOf", inner);
                         newAllOf.add(refSchema); // replace with ref
+                        atLeastOneModel = true;
                     } else {
                         newAllOf.add(inner);
                     }
                 }
-                m.setAllOf(newAllOf);
+                if (atLeastOneModel) {
+                    m.setAllOf(newAllOf);
+                } else {
+                    // allOf is just one or more types only so do not generate the inline allOf model
+                    if (m.getAllOf().size() == 1) {
+                        // handle earlier in this function when looping through properites
+                    } else if (m.getAllOf().size() > 1) {
+                        LOGGER.warn("allOf schema `{}` containing multiple types (not model) is not supported at the moment.", schema.getName());
+                    } else {
+                        LOGGER.error("allOf schema `{}` contains no items.", schema.getName());
+                    }
+                }
             }
             if (m.getAnyOf() != null) {
                 List<Schema> newAnyOf = new ArrayList<Schema>();

samples/client/petstore/csharp/OpenAPIClient/.openapi-generator/FILES

@@ -6,7 +6,6 @@ build.bat
 build.sh
 docs/AdditionalPropertiesClass.md
 docs/AllOfWithSingleRef.md
-docs/AllOfWithSingleRefSingleRefType.md
 docs/Animal.md
 docs/AnotherFakeApi.md
 docs/ApiResponse.md
@@ -81,7 +80,6 @@ src/Org.OpenAPITools/Client/IReadableConfiguration.cs
 src/Org.OpenAPITools/Client/OpenAPIDateConverter.cs
 src/Org.OpenAPITools/Model/AdditionalPropertiesClass.cs
 src/Org.OpenAPITools/Model/AllOfWithSingleRef.cs
-src/Org.OpenAPITools/Model/AllOfWithSingleRefSingleRefType.cs
 src/Org.OpenAPITools/Model/Animal.cs
 src/Org.OpenAPITools/Model/ApiResponse.cs
 src/Org.OpenAPITools/Model/ArrayOfArrayOfNumberOnly.cs

samples/client/petstore/csharp/OpenAPIClient/README.md

@@ -152,7 +152,6 @@ Class | Method | HTTP request | Description
 
  - [Model.AdditionalPropertiesClass](docs/AdditionalPropertiesClass.md)
  - [Model.AllOfWithSingleRef](docs/AllOfWithSingleRef.md)
- - [Model.AllOfWithSingleRefSingleRefType](docs/AllOfWithSingleRefSingleRefType.md)
  - [Model.Animal](docs/Animal.md)
  - [Model.ApiResponse](docs/ApiResponse.md)
  - [Model.ArrayOfArrayOfNumberOnly](docs/ArrayOfArrayOfNumberOnly.md)

samples/client/petstore/csharp/OpenAPIClient/docs/AllOfWithSingleRef.md

@@ -6,7 +6,7 @@
 Name | Type | Description | Notes
 ------------ | ------------- | ------------- | -------------
 **Username** | **string** |  | [optional] 
-**SingleRefType** | [**AllOfWithSingleRefSingleRefType**](AllOfWithSingleRefSingleRefType.md) |  | [optional] 
+**SingleRefType** | **SingleRefType** |  | [optional] 
 
 [[Back to Model list]](../README.md#documentation-for-models)
 [[Back to API list]](../README.md#documentation-for-api-endpoints)

samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/AllOfWithSingleRef.cs

@@ -30,12 +30,17 @@ namespace Org.OpenAPITools.Model
     [DataContract]
     public partial class AllOfWithSingleRef :  IEquatable<AllOfWithSingleRef>, IValidatableObject
     {
+        /// <summary>
+        /// Gets or Sets SingleRefType
+        /// </summary>
+        [DataMember(Name="SingleRefType", EmitDefaultValue=false)]
+        public SingleRefType? SingleRefType { get; set; }
         /// <summary>
         /// Initializes a new instance of the <see cref="AllOfWithSingleRef" /> class.
         /// </summary>
         /// <param name="username">username.</param>
         /// <param name="singleRefType">singleRefType.</param>
-        public AllOfWithSingleRef(string username = default(string), AllOfWithSingleRefSingleRefType singleRefType = default(AllOfWithSingleRefSingleRefType))
+        public AllOfWithSingleRef(string username = default(string), SingleRefType? singleRefType = default(SingleRefType?))
         {
             this.Username = username;
             this.SingleRefType = singleRefType;
@@ -47,11 +52,6 @@ public partial class AllOfWithSingleRef :  IEquatable<AllOfWithSingleRef>, IVali
         [DataMember(Name="username", EmitDefaultValue=false)]
         public string Username { get; set; }
 
-        /// <summary>
-        /// Gets or Sets SingleRefType
-        /// </summary>
-        [DataMember(Name="SingleRefType", EmitDefaultValue=false)]
-        public AllOfWithSingleRefSingleRefType SingleRefType { get; set; }
 
         /// <summary>
         /// Returns the string presentation of the object

samples/client/petstore/elixir/.openapi-generator/FILES

@@ -13,7 +13,6 @@ lib/openapi_petstore/deserializer.ex
 lib/openapi_petstore/model/_special_model_name_.ex
 lib/openapi_petstore/model/additional_properties_class.ex
 lib/openapi_petstore/model/all_of_with_single_ref.ex
-lib/openapi_petstore/model/all_of_with_single_ref_single_ref_type.ex
 lib/openapi_petstore/model/animal.ex
 lib/openapi_petstore/model/api_response.ex
 lib/openapi_petstore/model/array_of_array_of_number_only.ex

samples/client/petstore/elixir/lib/openapi_petstore/model/all_of_with_single_ref.ex

@@ -15,15 +15,15 @@ defmodule OpenapiPetstore.Model.AllOfWithSingleRef do
 
   @type t :: %__MODULE__{
     :"username" => String.t | nil,
-    :"SingleRefType" => OpenapiPetstore.Model.AllOfWithSingleRefSingleRefType.t | nil
+    :"SingleRefType" => OpenapiPetstore.Model.SingleRefType.t | nil
   }
 end
 
 defimpl Poison.Decoder, for: OpenapiPetstore.Model.AllOfWithSingleRef do
   import OpenapiPetstore.Deserializer
   def decode(value, options) do
     value
-    |> deserialize(:"SingleRefType", :struct, OpenapiPetstore.Model.AllOfWithSingleRefSingleRefType, options)
+    |> deserialize(:"SingleRefType", :struct, OpenapiPetstore.Model.SingleRefType, options)
   end
 end
 

samples/client/petstore/java/feign/.openapi-generator/FILES

@@ -40,7 +40,6 @@ src/main/java/org/openapitools/client/auth/OauthClientCredentialsGrant.java
 src/main/java/org/openapitools/client/auth/OauthPasswordGrant.java
 src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
 src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
-src/main/java/org/openapitools/client/model/AllOfWithSingleRefSingleRefType.java
 src/main/java/org/openapitools/client/model/Animal.java
 src/main/java/org/openapitools/client/model/ApiResponse.java
 src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java

samples/client/petstore/java/feign/api/openapi.yaml

@@ -2119,7 +2119,7 @@ components:
         username:
           type: string
         SingleRefType:
-          $ref: '#/components/schemas/AllOfWithSingleRef_SingleRefType'
+          $ref: '#/components/schemas/SingleRefType'
       type: object
     SingleRefType:
       enum:
@@ -2280,9 +2280,6 @@ components:
         declawed:
           type: boolean
       type: object
-    AllOfWithSingleRef_SingleRefType:
-      allOf:
-      - $ref: '#/components/schemas/SingleRefType'
   securitySchemes:
     petstore_auth:
       flows: