Fix #20304 : preserve sibling properties on $ref

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

@@ -5006,4 +5006,41 @@ public void testSingleRequestParameter_hasSingleParamTrue() {
         // When & Then
         assertThat(codegenOperation.getHasSingleParam()).isTrue();
     }
+
+    @Test
+    public void testRefSiblingMergingOnAllAliasForms() {
+        // 1) load & flatten
+        OpenAPI openAPI = TestUtils.parseFlattenSpec(
+                "src/test/resources/3_1/issue_20304.yaml"
+        );
+        new InlineModelResolver().flatten(openAPI);
+
+        // 2) prepare codegen
+        DefaultCodegen codegen = new DefaultCodegen();
+        codegen.setOpenAPI(openAPI);
+
+        // 3) grab all five wrapper props
+        Map<String, Schema> props = openAPI.getComponents()
+                .getSchemas()
+                .get("ModelWithTitledProperties")
+                .getProperties();
+
+        // 4) for each case: [propertyName, expectedTitle, expectedDescription]
+        String[][] cases = {
+                {"simpleProperty", "Simple-Property-Title", "Simple-Property-Description"},
+                {"allOfRefProperty", "All-Of-Ref-Property-Title", "All-Of-Ref-Property-Description"},
+                {"arrayRefProperty", "Array-Ref-Property-Title", "Array-Ref-Property-Description"},
+                {"mapRefProperty", "Map-Ref-Property-Title", "Map-Ref-Property-Description"},
+                {"objectRefProperty", "Object-Ref-Property-Title", "Object-Ref-Property-Description"}
+        };
+
+        for (String[] c : cases) {
+            // required flag is irrelevant for merging siblings
+            CodegenProperty cp = codegen.fromProperty(c[0], props.get(c[0]), true);
+
+            // assert that our override‐siblings came through
+            assertEquals(c[1], cp.getTitle(), c[0] + " → title");
+            assertEquals(c[2], cp.getDescription(), c[0] + " → description");
+        }
+    }
 }

modules/openapi-generator/src/test/resources/3_1/issue_20304.yaml

@@ -0,0 +1,59 @@
+# src/test/resources/3_1/issue_20304_siblings.yaml
+openapi: 3.1.0
+info:
+  title: Test siblings
+  version: 1.0.0
+components:
+  schemas:
+    ModelWithTitledProperties:
+      type: object
+      properties:
+        # 1) simple $ref
+        simpleProperty:
+          $ref: '#/components/schemas/Inner'
+          title: Simple-Property-Title
+          description: Simple-Property-Description
+
+        # 2) allOf wrapping a $ref
+        allOfRefProperty:
+          allOf:
+            - $ref: '#/components/schemas/Inner'
+          title: All-Of-Ref-Property-Title
+          description: All-Of-Ref-Property-Description
+
+        # 3) array alias
+        arrayRefProperty:
+          $ref: '#/components/schemas/ArrayOfInner'
+          title: Array-Ref-Property-Title
+          description: Array-Ref-Property-Description
+
+        # 4) map alias
+        mapRefProperty:
+          $ref: '#/components/schemas/MapOfInner'
+          title: Map-Ref-Property-Title
+          description: Map-Ref-Property-Description
+
+        # 5) object-model alias
+        objectRefProperty:
+          $ref: '#/components/schemas/ObjectInner'
+          title: Object-Ref-Property-Title
+          description: Object-Ref-Property-Description
+
+    Inner:
+      type: string
+
+    ArrayOfInner:
+      type: array
+      items:
+        $ref: '#/components/schemas/Inner'
+
+    MapOfInner:
+      type: object
+      additionalProperties:
+        $ref: '#/components/schemas/Inner'
+
+    ObjectInner:
+      type: object
+      properties:
+        foo:
+          type: integer

samples/client/others/rust/reqwest-regression-16119/Cargo.toml

@@ -9,6 +9,7 @@ edition = "2021"
 
 [dependencies]
 serde = { version = "^1.0", features = ["derive"] }
+serde_with = { version = "^3.8", default-features = false, features = ["base64", "std", "macros"] }
 serde_json = "^1.0"
 serde_repr = "^0.1"
 url = "^2.5"

samples/client/others/rust/reqwest-regression-16119/src/models/parent.rs

@@ -13,8 +13,8 @@ use serde::{Deserialize, Serialize};
 
 #[derive(Clone, Default, Debug, PartialEq, Serialize, Deserialize)]
 pub struct Parent {
-    #[serde(rename = "child", skip_serializing_if = "Option::is_none")]
-    pub child: Option<std::collections::HashMap<String, serde_json::Value>>,
+    #[serde(rename = "child", default, with = "::serde_with::rust::double_option", skip_serializing_if = "Option::is_none")]
+    pub child: Option<Option<std::collections::HashMap<String, serde_json::Value>>>,
 }
 
 impl Parent {

samples/client/petstore/java/okhttp-gson-3.1/api/openapi.yaml

@@ -1100,7 +1100,8 @@ components:
         ref_array_prefix_items:
           description: |
             An item that was added to the queue.
-          items: {}
+          items:
+            type: object
           maxItems: 5
           minItems: 3
           type: array

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

@@ -1859,7 +1859,6 @@ components:
     Address:
       additionalProperties:
         type: integer
-      default: []
       type: object
     Animal:
       discriminator:
@@ -2258,7 +2257,6 @@ components:
     StringBooleanMap:
       additionalProperties:
         type: boolean
-      default: []
       type: object
     FileSchemaTestClass:
       example:
@@ -2597,7 +2595,6 @@ components:
       - $ref: "#/components/schemas/GrandparentAnimal"
       type: object
     ArrayOfEnums:
-      default: []
       items:
         $ref: "#/components/schemas/OuterEnum"
       type: array
@@ -2744,7 +2741,6 @@ components:
       - type: boolean
       description: Values of scalar type using anyOf
     Array:
-      default: []
       description: Values of array type
       items:
         $ref: "#/components/schemas/Scalar"

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

@@ -749,6 +749,7 @@ components:
         requiredObjectHeader:
           type: boolean
         optionalObjectHeader:
+          format: int32
           type: integer
       required:
       - requiredObjectHeader

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

@@ -749,6 +749,7 @@ components:
         requiredObjectHeader:
           type: boolean
         optionalObjectHeader:
+          format: int32
           type: integer
       required:
       - requiredObjectHeader