Never create inline model for allOf with single $ref

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

@@ -231,7 +231,9 @@ private boolean isModelNeeded(Schema schema, Set<Schema> visitedSchemas) {
                 if (schema.equals(c)) {
                     return isModelNeeded((Schema) schema.getAllOf().get(0), visitedSchemas);
                 }
-            } else if (isSingleAllOf && StringUtils.isNotEmpty(((Schema) schema.getAllOf().get(0)).get$ref())) {
+            }
+
+            if (isSingleAllOf && StringUtils.isNotEmpty(((Schema) schema.getAllOf().get(0)).get$ref())) {
                 // single allOf and it's a ref
                 return isModelNeeded((Schema) schema.getAllOf().get(0), visitedSchemas);
             }

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

@@ -1171,4 +1171,30 @@ public void resolveOperationInlineEnumFormParameters() {
                 ((Schema) inlineFormParaemter.getProperties().get("enum_form_string")).get$ref());
 
     }
+
+    @Test
+    public void doNotWrapSingleAllOfRefs() {
+        OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_0/issue_15077.yaml");
+        new InlineModelResolver().flatten(openAPI);
+
+        // None of these cases should be wrapped in an inline schema and should reference the original schema "NumberRange"
+        Schema limitsModel = (Schema) openAPI.getComponents().getSchemas().get("Limits");
+        final String numberRangeRef = "#/components/schemas/NumberRange";
+
+        Schema allOfRef = (Schema) limitsModel.getProperties().get("allOfRef");
+        assertNotNull(allOfRef.getAllOf());
+        assertEquals(numberRangeRef, ((Schema) allOfRef.getAllOf().get(0)).get$ref());
+
+        Schema allOfRefWithDescription = (Schema) limitsModel.getProperties().get("allOfRefWithDescription");
+        assertNotNull(allOfRefWithDescription.getAllOf());
+        assertEquals(numberRangeRef, ((Schema) allOfRefWithDescription.getAllOf().get(0)).get$ref());
+
+        Schema allOfRefWithReadonly = (Schema) limitsModel.getProperties().get("allOfRefWithReadonly");
+        assertNotNull(allOfRefWithReadonly.getAllOf());
+        assertEquals(numberRangeRef, ((Schema) allOfRefWithReadonly.getAllOf().get(0)).get$ref());
+
+        Schema allOfRefWithDescriptionAndReadonly = (Schema) limitsModel.getProperties().get("allOfRefWithDescriptionAndReadonly");
+        assertNotNull(allOfRefWithDescriptionAndReadonly.getAllOf());
+        assertEquals(numberRangeRef, ((Schema) allOfRefWithDescriptionAndReadonly.getAllOf().get(0)).get$ref());
+    }
 }

modules/openapi-generator/src/test/resources/3_0/issue_15077.yaml

@@ -0,0 +1,53 @@
+openapi: 3.0.0
+info:
+  version: 1.0.0
+  title: Property refs using allOf
+paths:
+  /limits:
+    get:
+      operationId: getLimits
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Limits'
+components:
+  schemas:
+    NumberRange:
+      type: object
+      properties:
+        min:
+          type: number
+        max:
+          type: number
+      required:
+        - min
+        - max
+    Limits:
+      type: object
+      properties:
+        allOfRef:
+          allOf:
+            - $ref: '#/components/schemas/NumberRange'
+        allOfRefWithDescription:
+          description: |
+            Description for this property
+          allOf:
+            - $ref: '#/components/schemas/NumberRange'
+        allOfRefWithReadonly:
+          readOnly: true
+          allOf:
+            - $ref: '#/components/schemas/NumberRange'
+        allOfRefWithDescriptionAndReadonly:
+          description: |
+            Description for this readonly property
+          readOnly: true
+          allOf:
+            - $ref: '#/components/schemas/NumberRange'
+      required:
+        - allOfRef
+        - allOfRefWithDescription
+        - allOfRefWithReadonly
+        - allOfRefWithDescriptionAndReadonly

modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-okhttp-gson.yaml

@@ -1217,7 +1217,7 @@ paths:
       operationId: getParameterNameMapping
       parameters:
         - name: _type
-          in: header 
+          in: header
           description: _type
           required: true
           schema:
@@ -1230,7 +1230,7 @@ paths:
           schema:
             type: string
         - name: type_
-          in: header 
+          in: header
           description: type_
           required: true
           schema:
@@ -1246,7 +1246,7 @@ paths:
       operationId: getParameterStringNumber
       parameters:
         - name: string_number
-          in: header 
+          in: header
           description: string number
           required: true
           schema:
@@ -2600,6 +2600,17 @@ components:
         category_allOf_ref:
           allOf:
             - $ref: '#/components/schemas/Category'
+        category_allOf_ref_description:
+          description: |
+            Adding description to property using allOf
+          allOf:
+            - $ref: '#/components/schemas/Category'
+        category_allOf_ref_description_readonly:
+          description: |
+            Adding description to readonly property using allOf
+          readOnly: true
+          allOf:
+            - $ref: '#/components/schemas/Category'
         name:
           type: string
           example: doggie

samples/client/petstore/java/okhttp-gson/api/openapi.yaml

@@ -2640,6 +2640,17 @@ components:
         category_allOf_ref:
           allOf:
           - $ref: '#/components/schemas/Category'
+        category_allOf_ref_description:
+          allOf:
+          - $ref: '#/components/schemas/Category'
+          description: |
+            Adding description to property using allOf
+        category_allOf_ref_description_readonly:
+          allOf:
+          - $ref: '#/components/schemas/Category'
+          description: |
+            Adding description to readonly property using allOf
+          readOnly: true
         name:
           example: doggie
           type: string

samples/client/petstore/java/okhttp-gson/docs/NewPet.md

@@ -10,6 +10,8 @@
 |**id** | **Long** |  |  [optional] |
 |**categoryInlineAllof** | [**NewPetCategoryInlineAllof**](NewPetCategoryInlineAllof.md) |  |  [optional] |
 |**categoryAllOfRef** | [**Category**](Category.md) |  |  [optional] |
+|**categoryAllOfRefDescription** | [**Category**](Category.md) | Adding description to property using allOf  |  [optional] |
+|**categoryAllOfRefDescriptionReadonly** | [**Category**](Category.md) | Adding description to readonly property using allOf  |  [optional] [readonly] |
 |**name** | **String** |  |  |
 |**photoUrls** | **List<String>** |  |  |
 |**tags** | [**List<Tag>**](Tag.md) |  |  [optional] |

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPet.java

@@ -68,6 +68,14 @@ public class NewPet {
   @SerializedName(SERIALIZED_NAME_CATEGORY_ALL_OF_REF)
   private Category categoryAllOfRef;
 
+  public static final String SERIALIZED_NAME_CATEGORY_ALL_OF_REF_DESCRIPTION = "category_allOf_ref_description";
+  @SerializedName(SERIALIZED_NAME_CATEGORY_ALL_OF_REF_DESCRIPTION)
+  private Category categoryAllOfRefDescription;
+
+  public static final String SERIALIZED_NAME_CATEGORY_ALL_OF_REF_DESCRIPTION_READONLY = "category_allOf_ref_description_readonly";
+  @SerializedName(SERIALIZED_NAME_CATEGORY_ALL_OF_REF_DESCRIPTION_READONLY)
+  private Category categoryAllOfRefDescriptionReadonly;
+
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
   private String name;
@@ -141,6 +149,13 @@ public static void validateJsonElement(JsonElement jsonElement) throws IOExcepti
   public NewPet() {
   }
 
+  public NewPet(
+     Category categoryAllOfRefDescriptionReadonly
+  ) {
+    this();
+    this.categoryAllOfRefDescriptionReadonly = categoryAllOfRefDescriptionReadonly;
+  }
+
   public NewPet id(Long id) {
     this.id = id;
     return this;
@@ -198,6 +213,36 @@ public void setCategoryAllOfRef(Category categoryAllOfRef) {
   }
 
 
+  public NewPet categoryAllOfRefDescription(Category categoryAllOfRefDescription) {
+    this.categoryAllOfRefDescription = categoryAllOfRefDescription;
+    return this;
+  }
+
+  /**
+   * Adding description to property using allOf 
+   * @return categoryAllOfRefDescription
+   */
+  @javax.annotation.Nullable
+  public Category getCategoryAllOfRefDescription() {
+    return categoryAllOfRefDescription;
+  }
+
+  public void setCategoryAllOfRefDescription(Category categoryAllOfRefDescription) {
+    this.categoryAllOfRefDescription = categoryAllOfRefDescription;
+  }
+
+
+  /**
+   * Adding description to readonly property using allOf 
+   * @return categoryAllOfRefDescriptionReadonly
+   */
+  @javax.annotation.Nullable
+  public Category getCategoryAllOfRefDescriptionReadonly() {
+    return categoryAllOfRefDescriptionReadonly;
+  }
+
+
+
   public NewPet name(String name) {
     this.name = name;
     return this;
@@ -347,6 +392,8 @@ public boolean equals(Object o) {
     return Objects.equals(this.id, newPet.id) &&
         Objects.equals(this.categoryInlineAllof, newPet.categoryInlineAllof) &&
         Objects.equals(this.categoryAllOfRef, newPet.categoryAllOfRef) &&
+        Objects.equals(this.categoryAllOfRefDescription, newPet.categoryAllOfRefDescription) &&
+        Objects.equals(this.categoryAllOfRefDescriptionReadonly, newPet.categoryAllOfRefDescriptionReadonly) &&
         Objects.equals(this.name, newPet.name) &&
         Objects.equals(this.photoUrls, newPet.photoUrls) &&
         Objects.equals(this.tags, newPet.tags) &&
@@ -356,7 +403,7 @@ public boolean equals(Object o) {
 
   @Override
   public int hashCode() {
-    return Objects.hash(id, categoryInlineAllof, categoryAllOfRef, name, photoUrls, tags, status, additionalProperties);
+    return Objects.hash(id, categoryInlineAllof, categoryAllOfRef, categoryAllOfRefDescription, categoryAllOfRefDescriptionReadonly, name, photoUrls, tags, status, additionalProperties);
   }
 
   @Override
@@ -366,6 +413,8 @@ public String toString() {
     sb.append("    id: ").append(toIndentedString(id)).append("\n");
     sb.append("    categoryInlineAllof: ").append(toIndentedString(categoryInlineAllof)).append("\n");
     sb.append("    categoryAllOfRef: ").append(toIndentedString(categoryAllOfRef)).append("\n");
+    sb.append("    categoryAllOfRefDescription: ").append(toIndentedString(categoryAllOfRefDescription)).append("\n");
+    sb.append("    categoryAllOfRefDescriptionReadonly: ").append(toIndentedString(categoryAllOfRefDescriptionReadonly)).append("\n");
     sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("    photoUrls: ").append(toIndentedString(photoUrls)).append("\n");
     sb.append("    tags: ").append(toIndentedString(tags)).append("\n");
@@ -396,6 +445,8 @@ private String toIndentedString(Object o) {
     openapiFields.add("id");
     openapiFields.add("category_inline_allof");
     openapiFields.add("category_allOf_ref");
+    openapiFields.add("category_allOf_ref_description");
+    openapiFields.add("category_allOf_ref_description_readonly");
     openapiFields.add("name");
     openapiFields.add("photoUrls");
     openapiFields.add("tags");
@@ -435,6 +486,14 @@ public static void validateJsonElement(JsonElement jsonElement) throws IOExcepti
       if (jsonObj.get("category_allOf_ref") != null && !jsonObj.get("category_allOf_ref").isJsonNull()) {
         Category.validateJsonElement(jsonObj.get("category_allOf_ref"));
       }
+      // validate the optional field `category_allOf_ref_description`
+      if (jsonObj.get("category_allOf_ref_description") != null && !jsonObj.get("category_allOf_ref_description").isJsonNull()) {
+        Category.validateJsonElement(jsonObj.get("category_allOf_ref_description"));
+      }
+      // validate the optional field `category_allOf_ref_description_readonly`
+      if (jsonObj.get("category_allOf_ref_description_readonly") != null && !jsonObj.get("category_allOf_ref_description_readonly").isJsonNull()) {
+        Category.validateJsonElement(jsonObj.get("category_allOf_ref_description_readonly"));
+      }
       if (!jsonObj.get("name").isJsonPrimitive()) {
         throw new IllegalArgumentException(String.format("Expected the field `name` to be a primitive type in the JSON string but got `%s`", jsonObj.get("name").toString()));
       }