[OpenAPI 3.1] Avoid NPE when handling prefixItems (#19735)

* avoid npe when handling prefixItems in 3.1 spec

* update samples

Author: wing328

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

@@ -1280,6 +1280,9 @@ private Schema processNormalize31Spec(Schema schema, Set<Schema> visitedSchemas)
                         Schema updatedItems = normalizeSchema(schema.getItems(), visitedSchemas);
                         as.setItems(updatedItems);
                     }
+                } else {
+                    // when items is not defined, default to any type
+                    as.setItems(new Schema());
                 }
 
                 return as;

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

@@ -600,6 +600,11 @@ public void testOpenAPINormalizerProcessingArraySchema31Spec() {
         assertEquals(((Schema) schema5.getProperties().get("arrayOfStrings")).getItems().getType(), null);
         assertEquals(((Schema) schema5.getProperties().get("arrayOfStrings")).getItems().getTypes().contains("string"), true);
 
+        Schema schema7 = openAPI.getComponents().getSchemas().get("ArrayWithPrefixItems");
+        assertEquals(((Schema) schema7.getProperties().get("with_prefixitems")).getItems(), null);
+        assertNotEquals(((Schema) schema7.getProperties().get("with_prefixitems")).getPrefixItems(), null);
+        assertEquals(((Schema) schema7.getProperties().get("without_items")).getItems(), null);
+
         Map<String, String> inputRules = Map.of("NORMALIZE_31SPEC", "true");
         OpenAPINormalizer openAPINormalizer = new OpenAPINormalizer(openAPI, inputRules);
         openAPINormalizer.normalize();
@@ -622,6 +627,11 @@ public void testOpenAPINormalizerProcessingArraySchema31Spec() {
         assertEquals(((Schema) schema6.getProperties().get("arrayOfStrings")).getItems().getTypes().contains("string"), true);
         assertEquals(((Schema) schema6.getProperties().get("arrayOfStrings")).getItems().getType(), "string");
         assertEquals(((Schema) schema6.getProperties().get("arrayOfStrings")).getType(), "array");
+
+        Schema schema8 = openAPI.getComponents().getSchemas().get("ArrayWithPrefixItems");
+        assertNotEquals(((Schema) schema8.getProperties().get("with_prefixitems")).getItems(), null);
+        assertEquals(((Schema) schema8.getProperties().get("with_prefixitems")).getPrefixItems(), null);
+        assertNotEquals(((Schema) schema8.getProperties().get("without_items")).getItems(), null);
     }
 
     @Test

modules/openapi-generator/src/test/resources/3_1/issue_18291.yaml

@@ -30,7 +30,20 @@ components:
           type: array
           items:
             type: string
-
     Bar:
       allOf:
-        - $ref: '#/components/schemas/Foo'
+        - $ref: '#/components/schemas/Foo'
+    ArrayWithPrefixItems:
+      type: object
+      properties:
+        with_prefixitems:
+          type: array
+          prefixItems:
+            - type: number
+              title: Longitude
+            - type: number
+              title: Latitude
+          maxItems: 2
+          minItems: 2
+        without_items:
+          type: array

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

@@ -1099,9 +1099,7 @@ components:
         ref_array_prefix_items:
           description: |
             An item that was added to the queue.
-          items:
-            description: TODO default missing array inner type to string
-            type: string
+          items: {}
           maxItems: 5
           minItems: 3
           type: array
@@ -1112,9 +1110,7 @@ components:
     ArrayPrefixItems:
       description: |
         An item that was added to the queue.
-      items:
-        description: TODO default missing array inner type to string
-        type: string
+      items: {}
       maxItems: 5
       minItems: 3
       type: array

samples/client/petstore/java/okhttp-gson-3.1/docs/AnyTypeTest.md

@@ -9,7 +9,7 @@
 |------------ | ------------- | ------------- | -------------|
 |**anyTypeProperty** | **Object** |  |  [optional] |
 |**arrayProp** | **List<String>** | test array in 3.1 spec |  [optional] |
-|**refArrayPrefixItems** | **List<String>** | An item that was added to the queue.  |  [optional] |
+|**refArrayPrefixItems** | **List<Object>** | An item that was added to the queue.  |  [optional] |
 
 
 

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AnyTypeTest.java

@@ -63,7 +63,7 @@ public class AnyTypeTest {
 
   public static final String SERIALIZED_NAME_REF_ARRAY_PREFIX_ITEMS = "ref_array_prefix_items";
   @SerializedName(SERIALIZED_NAME_REF_ARRAY_PREFIX_ITEMS)
-  private List<String> refArrayPrefixItems = new ArrayList<>();
+  private List<Object> refArrayPrefixItems = new ArrayList<>();
 
   public AnyTypeTest() {
   }
@@ -114,12 +114,12 @@ public void setArrayProp(List<String> arrayProp) {
   }
 
 
-  public AnyTypeTest refArrayPrefixItems(List<String> refArrayPrefixItems) {
+  public AnyTypeTest refArrayPrefixItems(List<Object> refArrayPrefixItems) {
     this.refArrayPrefixItems = refArrayPrefixItems;
     return this;
   }
 
-  public AnyTypeTest addRefArrayPrefixItemsItem(String refArrayPrefixItemsItem) {
+  public AnyTypeTest addRefArrayPrefixItemsItem(Object refArrayPrefixItemsItem) {
     if (this.refArrayPrefixItems == null) {
       this.refArrayPrefixItems = new ArrayList<>();
     }
@@ -132,11 +132,11 @@ public AnyTypeTest addRefArrayPrefixItemsItem(String refArrayPrefixItemsItem) {
    * @return refArrayPrefixItems
    */
   @javax.annotation.Nullable
-  public List<String> getRefArrayPrefixItems() {
+  public List<Object> getRefArrayPrefixItems() {
     return refArrayPrefixItems;
   }
 
-  public void setRefArrayPrefixItems(List<String> refArrayPrefixItems) {
+  public void setRefArrayPrefixItems(List<Object> refArrayPrefixItems) {
     this.refArrayPrefixItems = refArrayPrefixItems;
   }
 

samples/client/petstore/rust/reqwest/petstore-async-tokensource/src/models/numeric_enum_testing.rs

@@ -24,14 +24,14 @@ pub enum NumericEnumTesting {
 
 }
 
-impl ToString for NumericEnumTesting {
-    fn to_string(&self) -> String {
-        match self {
-            Self::Variant0 => String::from("0"),
-            Self::Variant1 => String::from("1"),
-            Self::Variant2 => String::from("2"),
-            Self::Variant3 => String::from("3"),
-        }
+impl std::fmt::Display for NumericEnumTesting {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", match self {
+            Self::Variant0 => "0",
+            Self::Variant1 => "1",
+            Self::Variant2 => "2",
+            Self::Variant3 => "3",
+        })
     }
 }
 impl Default for NumericEnumTesting {