Better handling of x-nullable in codegen property (#14800)

* add failed tests

* add logic to handle x-nullable in property

* update samples

* update test

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

@@ -3877,8 +3877,12 @@ public class DefaultCodegen implements CodegenConfig {
             }
         }
 
+        // set isNullable using nullable or x-nullable in the schema
         if (referencedSchema.getNullable() != null) {
             property.isNullable = referencedSchema.getNullable();
+        } else if (referencedSchema.getExtensions() != null &&
+                referencedSchema.getExtensions().containsKey("x-nullable")) {
+            property.isNullable = (Boolean) referencedSchema.getExtensions().get("x-nullable");
         }
 
         property.dataType = getTypeDeclaration(p);

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

@@ -451,6 +451,11 @@ components:
           type: array
           items:
             type: string
+        array_string_extension_nullable:
+          x-nullable: true
+          type: array
+          items:
+            type: string
         string_nullable:
           type: string
           nullable: true

samples/client/echo_api/java/apache-httpclient/api/openapi.yaml

@@ -466,6 +466,11 @@ components:
             type: string
           nullable: true
           type: array
+        array_string_extension_nullable:
+          items:
+            type: string
+          type: array
+          x-nullable: true
         string_nullable:
           nullable: true
           type: string

samples/client/echo_api/java/apache-httpclient/docs/DefaultValue.md

@@ -14,6 +14,7 @@ to test the default value of properties
 |**arrayIntegerDefault** | **List<Integer>** |  |  [optional] |
 |**arrayString** | **List<String>** |  |  [optional] |
 |**arrayStringNullable** | **List<String>** |  |  [optional] |
+|**arrayStringExtensionNullable** | **List<String>** |  |  [optional] |
 |**stringNullable** | **String** |  |  [optional] |
 
 

samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DefaultValue.java

@@ -43,6 +43,7 @@ import java.util.StringJoiner;
   DefaultValue.JSON_PROPERTY_ARRAY_INTEGER_DEFAULT,
   DefaultValue.JSON_PROPERTY_ARRAY_STRING,
   DefaultValue.JSON_PROPERTY_ARRAY_STRING_NULLABLE,
+  DefaultValue.JSON_PROPERTY_ARRAY_STRING_EXTENSION_NULLABLE,
   DefaultValue.JSON_PROPERTY_STRING_NULLABLE
 })
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
@@ -102,6 +103,9 @@ public class DefaultValue {
   public static final String JSON_PROPERTY_ARRAY_STRING_NULLABLE = "array_string_nullable";
   private JsonNullable<List<String>> arrayStringNullable = JsonNullable.<List<String>>undefined();
 
+  public static final String JSON_PROPERTY_ARRAY_STRING_EXTENSION_NULLABLE = "array_string_extension_nullable";
+  private JsonNullable<List<String>> arrayStringExtensionNullable = JsonNullable.<List<String>>undefined();
+
   public static final String JSON_PROPERTY_STRING_NULLABLE = "string_nullable";
   private JsonNullable<String> stringNullable = JsonNullable.<String>undefined();
 
@@ -324,6 +328,52 @@ public class DefaultValue {
   }
 
 
+  public DefaultValue arrayStringExtensionNullable(List<String> arrayStringExtensionNullable) {
+    this.arrayStringExtensionNullable = JsonNullable.<List<String>>of(arrayStringExtensionNullable);
+    
+    return this;
+  }
+
+  public DefaultValue addArrayStringExtensionNullableItem(String arrayStringExtensionNullableItem) {
+    if (this.arrayStringExtensionNullable == null || !this.arrayStringExtensionNullable.isPresent()) {
+      this.arrayStringExtensionNullable = JsonNullable.<List<String>>of(new ArrayList<>());
+    }
+    try {
+      this.arrayStringExtensionNullable.get().add(arrayStringExtensionNullableItem);
+    } catch (java.util.NoSuchElementException e) {
+      // this can never happen, as we make sure above that the value is present
+    }
+    return this;
+  }
+
+   /**
+   * Get arrayStringExtensionNullable
+   * @return arrayStringExtensionNullable
+  **/
+  @javax.annotation.Nullable
+  @JsonIgnore
+
+  public List<String> getArrayStringExtensionNullable() {
+        return arrayStringExtensionNullable.orElse(null);
+  }
+
+  @JsonProperty(JSON_PROPERTY_ARRAY_STRING_EXTENSION_NULLABLE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public JsonNullable<List<String>> getArrayStringExtensionNullable_JsonNullable() {
+    return arrayStringExtensionNullable;
+  }
+  
+  @JsonProperty(JSON_PROPERTY_ARRAY_STRING_EXTENSION_NULLABLE)
+  public void setArrayStringExtensionNullable_JsonNullable(JsonNullable<List<String>> arrayStringExtensionNullable) {
+    this.arrayStringExtensionNullable = arrayStringExtensionNullable;
+  }
+
+  public void setArrayStringExtensionNullable(List<String> arrayStringExtensionNullable) {
+    this.arrayStringExtensionNullable = JsonNullable.<List<String>>of(arrayStringExtensionNullable);
+  }
+
+
   public DefaultValue stringNullable(String stringNullable) {
     this.stringNullable = JsonNullable.<String>of(stringNullable);
     
@@ -373,6 +423,7 @@ public class DefaultValue {
         Objects.equals(this.arrayIntegerDefault, defaultValue.arrayIntegerDefault) &&
         Objects.equals(this.arrayString, defaultValue.arrayString) &&
         equalsNullable(this.arrayStringNullable, defaultValue.arrayStringNullable) &&
+        equalsNullable(this.arrayStringExtensionNullable, defaultValue.arrayStringExtensionNullable) &&
         equalsNullable(this.stringNullable, defaultValue.stringNullable);
   }
 
@@ -382,7 +433,7 @@ public class DefaultValue {
 
   @Override
   public int hashCode() {
-    return Objects.hash(arrayStringEnumRefDefault, arrayStringEnumDefault, arrayStringDefault, arrayIntegerDefault, arrayString, hashCodeNullable(arrayStringNullable), hashCodeNullable(stringNullable));
+    return Objects.hash(arrayStringEnumRefDefault, arrayStringEnumDefault, arrayStringDefault, arrayIntegerDefault, arrayString, hashCodeNullable(arrayStringNullable), hashCodeNullable(arrayStringExtensionNullable), hashCodeNullable(stringNullable));
   }
 
   private static <T> int hashCodeNullable(JsonNullable<T> a) {
@@ -402,6 +453,7 @@ public class DefaultValue {
     sb.append("    arrayIntegerDefault: ").append(toIndentedString(arrayIntegerDefault)).append("\n");
     sb.append("    arrayString: ").append(toIndentedString(arrayString)).append("\n");
     sb.append("    arrayStringNullable: ").append(toIndentedString(arrayStringNullable)).append("\n");
+    sb.append("    arrayStringExtensionNullable: ").append(toIndentedString(arrayStringExtensionNullable)).append("\n");
     sb.append("    stringNullable: ").append(toIndentedString(stringNullable)).append("\n");
     sb.append("}");
     return sb.toString();
@@ -536,6 +588,20 @@ public class DefaultValue {
       }
     }
 
+    // add `array_string_extension_nullable` to the URL query string
+    if (getArrayStringExtensionNullable() != null) {
+      for (int i = 0; i < getArrayStringExtensionNullable().size(); i++) {
+        try {
+          joiner.add(String.format("%sarray_string_extension_nullable%s%s=%s", prefix, suffix,
+              "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, i, containerSuffix),
+              URLEncoder.encode(String.valueOf(getArrayStringExtensionNullable().get(i)), "UTF-8").replaceAll("\\+", "%20")));
+        } catch (UnsupportedEncodingException e) {
+          // Should never happen, UTF-8 is always supported
+          throw new RuntimeException(e);
+        }
+      }
+    }
+
     // add `string_nullable` to the URL query string
     if (getStringNullable() != null) {
       try {

samples/client/echo_api/java/apache-httpclient/src/test/java/org/openapitools/client/CustomTest.java

@@ -220,7 +220,7 @@ public class CustomTest {
         Assert.assertNull(d.getArrayStringNullable());
         Assert.assertEquals(d.getArrayString().size(), 0);
 
-        Assert.assertEquals(apiClient.getObjectMapper().writeValueAsString(d), "{\"array_string_enum_ref_default\":[\"success\",\"failure\"],\"array_string_enum_default\":[\"success\",\"failure\"],\"array_string_default\":[\"failure\",\"skipped\"],\"array_integer_default\":[1,3],\"array_string\":[],\"array_string_nullable\":{\"present\":false},\"string_nullable\":{\"present\":false}}");
+        Assert.assertEquals(apiClient.getObjectMapper().writeValueAsString(d), "{\"array_string_enum_ref_default\":[\"success\",\"failure\"],\"array_string_enum_default\":[\"success\",\"failure\"],\"array_string_default\":[\"failure\",\"skipped\"],\"array_integer_default\":[1,3],\"array_string\":[],\"array_string_nullable\":{\"present\":false},\"array_string_extension_nullable\":{\"present\":false},\"string_nullable\":{\"present\":false}}");
     }
 
     @Test
@@ -248,7 +248,7 @@ public class CustomTest {
         Assert.assertNull(d.getArrayStringNullable());
         Assert.assertEquals(d.getArrayString().size(), 0);
 
-        Assert.assertEquals(apiClient.getObjectMapper().writeValueAsString(d), "{\"array_string_enum_ref_default\":[\"unclassified\"],\"array_string_enum_default\":[\"unclassified\"],\"array_string_default\":[\"failure\"],\"array_integer_default\":[1,3],\"array_string\":[],\"array_string_nullable\":{\"present\":false},\"string_nullable\":{\"present\":false}}");
+        Assert.assertEquals(apiClient.getObjectMapper().writeValueAsString(d), "{\"array_string_enum_ref_default\":[\"unclassified\"],\"array_string_enum_default\":[\"unclassified\"],\"array_string_default\":[\"failure\"],\"array_integer_default\":[1,3],\"array_string\":[],\"array_string_nullable\":{\"present\":false},\"array_string_extension_nullable\":{\"present\":false},\"string_nullable\":{\"present\":false}}");
     }
 
     @Test

samples/client/echo_api/java/feign-gson/api/openapi.yaml

@@ -466,6 +466,11 @@ components:
             type: string
           nullable: true
           type: array
+        array_string_extension_nullable:
+          items:
+            type: string
+          type: array
+          x-nullable: true
         string_nullable:
           nullable: true
           type: string

samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DefaultValue.java

@@ -104,6 +104,10 @@ public class DefaultValue {
   @SerializedName(SERIALIZED_NAME_ARRAY_STRING_NULLABLE)
   private List<String> arrayStringNullable;
 
+  public static final String SERIALIZED_NAME_ARRAY_STRING_EXTENSION_NULLABLE = "array_string_extension_nullable";
+  @SerializedName(SERIALIZED_NAME_ARRAY_STRING_EXTENSION_NULLABLE)
+  private List<String> arrayStringExtensionNullable;
+
   public static final String SERIALIZED_NAME_STRING_NULLABLE = "string_nullable";
   @SerializedName(SERIALIZED_NAME_STRING_NULLABLE)
   private String stringNullable;
@@ -288,6 +292,33 @@ public class DefaultValue {
   }
 
 
+  public DefaultValue arrayStringExtensionNullable(List<String> arrayStringExtensionNullable) {
+    
+    this.arrayStringExtensionNullable = arrayStringExtensionNullable;
+    return this;
+  }
+
+  public DefaultValue addArrayStringExtensionNullableItem(String arrayStringExtensionNullableItem) {
+    this.arrayStringExtensionNullable.add(arrayStringExtensionNullableItem);
+    return this;
+  }
+
+   /**
+   * Get arrayStringExtensionNullable
+   * @return arrayStringExtensionNullable
+  **/
+  @javax.annotation.Nullable
+
+  public List<String> getArrayStringExtensionNullable() {
+    return arrayStringExtensionNullable;
+  }
+
+
+  public void setArrayStringExtensionNullable(List<String> arrayStringExtensionNullable) {
+    this.arrayStringExtensionNullable = arrayStringExtensionNullable;
+  }
+
+
   public DefaultValue stringNullable(String stringNullable) {
     
     this.stringNullable = stringNullable;
@@ -325,6 +356,7 @@ public class DefaultValue {
         Objects.equals(this.arrayIntegerDefault, defaultValue.arrayIntegerDefault) &&
         Objects.equals(this.arrayString, defaultValue.arrayString) &&
         Objects.equals(this.arrayStringNullable, defaultValue.arrayStringNullable) &&
+        Objects.equals(this.arrayStringExtensionNullable, defaultValue.arrayStringExtensionNullable) &&
         Objects.equals(this.stringNullable, defaultValue.stringNullable);
   }
 
@@ -334,7 +366,7 @@ public class DefaultValue {
 
   @Override
   public int hashCode() {
-    return Objects.hash(arrayStringEnumRefDefault, arrayStringEnumDefault, arrayStringDefault, arrayIntegerDefault, arrayString, arrayStringNullable, stringNullable);
+    return Objects.hash(arrayStringEnumRefDefault, arrayStringEnumDefault, arrayStringDefault, arrayIntegerDefault, arrayString, arrayStringNullable, arrayStringExtensionNullable, stringNullable);
   }
 
   private static <T> int hashCodeNullable(JsonNullable<T> a) {
@@ -354,6 +386,7 @@ public class DefaultValue {
     sb.append("    arrayIntegerDefault: ").append(toIndentedString(arrayIntegerDefault)).append("\n");
     sb.append("    arrayString: ").append(toIndentedString(arrayString)).append("\n");
     sb.append("    arrayStringNullable: ").append(toIndentedString(arrayStringNullable)).append("\n");
+    sb.append("    arrayStringExtensionNullable: ").append(toIndentedString(arrayStringExtensionNullable)).append("\n");
     sb.append("    stringNullable: ").append(toIndentedString(stringNullable)).append("\n");
     sb.append("}");
     return sb.toString();

samples/client/echo_api/java/native/api/openapi.yaml

@@ -466,6 +466,11 @@ components:
             type: string
           nullable: true
           type: array
+        array_string_extension_nullable:
+          items:
+            type: string
+          type: array
+          x-nullable: true
         string_nullable:
           nullable: true
           type: string

samples/client/echo_api/java/native/docs/DefaultValue.md

@@ -14,6 +14,7 @@ to test the default value of properties
 |**arrayIntegerDefault** | **List<Integer>** |  |  [optional] |
 |**arrayString** | **List<String>** |  |  [optional] |
 |**arrayStringNullable** | **List<String>** |  |  [optional] |
+|**arrayStringExtensionNullable** | **List<String>** |  |  [optional] |
 |**stringNullable** | **String** |  |  [optional] |
 
 

samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DefaultValue.java

@@ -45,6 +45,7 @@ import com.fasterxml.jackson.annotation.JsonPropertyOrder;
   DefaultValue.JSON_PROPERTY_ARRAY_INTEGER_DEFAULT,
   DefaultValue.JSON_PROPERTY_ARRAY_STRING,
   DefaultValue.JSON_PROPERTY_ARRAY_STRING_NULLABLE,
+  DefaultValue.JSON_PROPERTY_ARRAY_STRING_EXTENSION_NULLABLE,
   DefaultValue.JSON_PROPERTY_STRING_NULLABLE
 })
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
@@ -104,6 +105,9 @@ public class DefaultValue {
   public static final String JSON_PROPERTY_ARRAY_STRING_NULLABLE = "array_string_nullable";
   private JsonNullable<List<String>> arrayStringNullable = JsonNullable.<List<String>>undefined();
 
+  public static final String JSON_PROPERTY_ARRAY_STRING_EXTENSION_NULLABLE = "array_string_extension_nullable";
+  private JsonNullable<List<String>> arrayStringExtensionNullable = JsonNullable.<List<String>>undefined();
+
   public static final String JSON_PROPERTY_STRING_NULLABLE = "string_nullable";
   private JsonNullable<String> stringNullable = JsonNullable.<String>undefined();
 
@@ -320,6 +324,51 @@ public class DefaultValue {
   }
 
 
+  public DefaultValue arrayStringExtensionNullable(List<String> arrayStringExtensionNullable) {
+    this.arrayStringExtensionNullable = JsonNullable.<List<String>>of(arrayStringExtensionNullable);
+    return this;
+  }
+
+  public DefaultValue addArrayStringExtensionNullableItem(String arrayStringExtensionNullableItem) {
+    if (this.arrayStringExtensionNullable == null || !this.arrayStringExtensionNullable.isPresent()) {
+      this.arrayStringExtensionNullable = JsonNullable.<List<String>>of(new ArrayList<>());
+    }
+    try {
+      this.arrayStringExtensionNullable.get().add(arrayStringExtensionNullableItem);
+    } catch (java.util.NoSuchElementException e) {
+      // this can never happen, as we make sure above that the value is present
+    }
+    return this;
+  }
+
+   /**
+   * Get arrayStringExtensionNullable
+   * @return arrayStringExtensionNullable
+  **/
+  @javax.annotation.Nullable
+  @JsonIgnore
+
+  public List<String> getArrayStringExtensionNullable() {
+        return arrayStringExtensionNullable.orElse(null);
+  }
+
+  @JsonProperty(JSON_PROPERTY_ARRAY_STRING_EXTENSION_NULLABLE)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+
+  public JsonNullable<List<String>> getArrayStringExtensionNullable_JsonNullable() {
+    return arrayStringExtensionNullable;
+  }
+  
+  @JsonProperty(JSON_PROPERTY_ARRAY_STRING_EXTENSION_NULLABLE)
+  public void setArrayStringExtensionNullable_JsonNullable(JsonNullable<List<String>> arrayStringExtensionNullable) {
+    this.arrayStringExtensionNullable = arrayStringExtensionNullable;
+  }
+
+  public void setArrayStringExtensionNullable(List<String> arrayStringExtensionNullable) {
+    this.arrayStringExtensionNullable = JsonNullable.<List<String>>of(arrayStringExtensionNullable);
+  }
+
+
   public DefaultValue stringNullable(String stringNullable) {
     this.stringNullable = JsonNullable.<String>of(stringNullable);
     return this;
@@ -371,6 +420,7 @@ public class DefaultValue {
         Objects.equals(this.arrayIntegerDefault, defaultValue.arrayIntegerDefault) &&
         Objects.equals(this.arrayString, defaultValue.arrayString) &&
         equalsNullable(this.arrayStringNullable, defaultValue.arrayStringNullable) &&
+        equalsNullable(this.arrayStringExtensionNullable, defaultValue.arrayStringExtensionNullable) &&
         equalsNullable(this.stringNullable, defaultValue.stringNullable);
   }
 
@@ -380,7 +430,7 @@ public class DefaultValue {
 
   @Override
   public int hashCode() {
-    return Objects.hash(arrayStringEnumRefDefault, arrayStringEnumDefault, arrayStringDefault, arrayIntegerDefault, arrayString, hashCodeNullable(arrayStringNullable), hashCodeNullable(stringNullable));
+    return Objects.hash(arrayStringEnumRefDefault, arrayStringEnumDefault, arrayStringDefault, arrayIntegerDefault, arrayString, hashCodeNullable(arrayStringNullable), hashCodeNullable(arrayStringExtensionNullable), hashCodeNullable(stringNullable));
   }
 
   private static <T> int hashCodeNullable(JsonNullable<T> a) {
@@ -400,6 +450,7 @@ public class DefaultValue {
     sb.append("    arrayIntegerDefault: ").append(toIndentedString(arrayIntegerDefault)).append("\n");
     sb.append("    arrayString: ").append(toIndentedString(arrayString)).append("\n");
     sb.append("    arrayStringNullable: ").append(toIndentedString(arrayStringNullable)).append("\n");
+    sb.append("    arrayStringExtensionNullable: ").append(toIndentedString(arrayStringExtensionNullable)).append("\n");
     sb.append("    stringNullable: ").append(toIndentedString(stringNullable)).append("\n");
     sb.append("}");
     return sb.toString();
@@ -504,6 +555,15 @@ public class DefaultValue {
       }
     }
 
+    // add `array_string_extension_nullable` to the URL query string
+    if (getArrayStringExtensionNullable() != null) {
+      for (int i = 0; i < getArrayStringExtensionNullable().size(); i++) {
+        joiner.add(String.format("%sarray_string_extension_nullable%s%s=%s", prefix, suffix,
+            "".equals(suffix) ? "" : String.format("%s%d%s", containerPrefix, i, containerSuffix),
+            URLEncoder.encode(String.valueOf(getArrayStringExtensionNullable().get(i)), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));
+      }
+    }
+
     // add `string_nullable` to the URL query string
     if (getStringNullable() != null) {
       joiner.add(String.format("%sstring_nullable%s=%s", prefix, suffix, URLEncoder.encode(String.valueOf(getStringNullable()), StandardCharsets.UTF_8).replaceAll("\\+", "%20")));

samples/client/echo_api/java/native/src/test/java/org/openapitools/client/CustomTest.java

@@ -167,8 +167,10 @@ public class CustomTest {
         Assert.assertEquals(d.getArrayIntegerDefault().get(1), Integer.valueOf(3));
 
         Assert.assertNull(d.getArrayStringNullable());
+        Assert.assertNull(d.getArrayStringExtensionNullable());
         Assert.assertEquals(d.getArrayString().size(), 0);
 
+
         // test addItem
         d.addArrayStringEnumDefaultItem(DefaultValue.ArrayStringEnumDefaultEnum.UNCLASSIFIED);
         Assert.assertEquals(d.getArrayStringEnumDefault().size(), 3);
@@ -209,6 +211,7 @@ public class CustomTest {
         Assert.assertEquals(d.getArrayIntegerDefault().get(1), Integer.valueOf(3));
 
         Assert.assertNull(d.getArrayStringNullable());
+        Assert.assertNull(d.getArrayStringExtensionNullable());
         Assert.assertEquals(d.getArrayString().size(), 0);
 
         Assert.assertEquals(apiClient.getObjectMapper().writeValueAsString(d), "{\"array_string_enum_ref_default\":[\"success\",\"failure\"],\"array_string_enum_default\":[\"success\",\"failure\"],\"array_string_default\":[\"failure\",\"skipped\"],\"array_integer_default\":[1,3],\"array_string\":[]}");
@@ -237,6 +240,7 @@ public class CustomTest {
         Assert.assertEquals(d.getArrayIntegerDefault().get(1), Integer.valueOf(3));
 
         Assert.assertNull(d.getArrayStringNullable());
+        Assert.assertNull(d.getArrayStringExtensionNullable());
         Assert.assertEquals(d.getArrayString().size(), 0);
 
         Assert.assertEquals(apiClient.getObjectMapper().writeValueAsString(d), "{\"array_string_enum_ref_default\":[\"unclassified\"],\"array_string_enum_default\":[\"unclassified\"],\"array_string_default\":[\"failure\"],\"array_integer_default\":[1,3],\"array_string\":[]}");

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

@@ -466,6 +466,11 @@ components:
             type: string
           nullable: true
           type: array
+        array_string_extension_nullable:
+          items:
+            type: string
+          type: array
+          x-nullable: true
         string_nullable:
           nullable: true
           type: string

samples/client/echo_api/java/okhttp-gson/docs/DefaultValue.md

@@ -14,6 +14,7 @@ to test the default value of properties
 |**arrayIntegerDefault** | **List<Integer>** |  |  [optional] |
 |**arrayString** | **List<String>** |  |  [optional] |
 |**arrayStringNullable** | **List<String>** |  |  [optional] |
+|**arrayStringExtensionNullable** | **List<String>** |  |  [optional] |
 |**stringNullable** | **String** |  |  [optional] |
 
 

samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DefaultValue.java

@@ -125,6 +125,10 @@ public class DefaultValue {
   @SerializedName(SERIALIZED_NAME_ARRAY_STRING_NULLABLE)
   private List<String> arrayStringNullable;
 
+  public static final String SERIALIZED_NAME_ARRAY_STRING_EXTENSION_NULLABLE = "array_string_extension_nullable";
+  @SerializedName(SERIALIZED_NAME_ARRAY_STRING_EXTENSION_NULLABLE)
+  private List<String> arrayStringExtensionNullable;
+
   public static final String SERIALIZED_NAME_STRING_NULLABLE = "string_nullable";
   @SerializedName(SERIALIZED_NAME_STRING_NULLABLE)
   private String stringNullable;
@@ -309,6 +313,33 @@ public class DefaultValue {
   }
 
 
+  public DefaultValue arrayStringExtensionNullable(List<String> arrayStringExtensionNullable) {
+    
+    this.arrayStringExtensionNullable = arrayStringExtensionNullable;
+    return this;
+  }
+
+  public DefaultValue addArrayStringExtensionNullableItem(String arrayStringExtensionNullableItem) {
+    this.arrayStringExtensionNullable.add(arrayStringExtensionNullableItem);
+    return this;
+  }
+
+   /**
+   * Get arrayStringExtensionNullable
+   * @return arrayStringExtensionNullable
+  **/
+  @javax.annotation.Nullable
+
+  public List<String> getArrayStringExtensionNullable() {
+    return arrayStringExtensionNullable;
+  }
+
+
+  public void setArrayStringExtensionNullable(List<String> arrayStringExtensionNullable) {
+    this.arrayStringExtensionNullable = arrayStringExtensionNullable;
+  }
+
+
   public DefaultValue stringNullable(String stringNullable) {
     
     this.stringNullable = stringNullable;
@@ -347,6 +378,7 @@ public class DefaultValue {
         Objects.equals(this.arrayIntegerDefault, defaultValue.arrayIntegerDefault) &&
         Objects.equals(this.arrayString, defaultValue.arrayString) &&
         Objects.equals(this.arrayStringNullable, defaultValue.arrayStringNullable) &&
+        Objects.equals(this.arrayStringExtensionNullable, defaultValue.arrayStringExtensionNullable) &&
         Objects.equals(this.stringNullable, defaultValue.stringNullable);
   }
 
@@ -356,7 +388,7 @@ public class DefaultValue {
 
   @Override
   public int hashCode() {
-    return Objects.hash(arrayStringEnumRefDefault, arrayStringEnumDefault, arrayStringDefault, arrayIntegerDefault, arrayString, arrayStringNullable, stringNullable);
+    return Objects.hash(arrayStringEnumRefDefault, arrayStringEnumDefault, arrayStringDefault, arrayIntegerDefault, arrayString, arrayStringNullable, arrayStringExtensionNullable, stringNullable);
   }
 
   private static <T> int hashCodeNullable(JsonNullable<T> a) {
@@ -376,6 +408,7 @@ public class DefaultValue {
     sb.append("    arrayIntegerDefault: ").append(toIndentedString(arrayIntegerDefault)).append("\n");
     sb.append("    arrayString: ").append(toIndentedString(arrayString)).append("\n");
     sb.append("    arrayStringNullable: ").append(toIndentedString(arrayStringNullable)).append("\n");
+    sb.append("    arrayStringExtensionNullable: ").append(toIndentedString(arrayStringExtensionNullable)).append("\n");
     sb.append("    stringNullable: ").append(toIndentedString(stringNullable)).append("\n");
     sb.append("}");
     return sb.toString();
@@ -405,6 +438,7 @@ public class DefaultValue {
     openapiFields.add("array_integer_default");
     openapiFields.add("array_string");
     openapiFields.add("array_string_nullable");
+    openapiFields.add("array_string_extension_nullable");
     openapiFields.add("string_nullable");
 
     // a set of required properties/fields (JSON key names)
@@ -455,6 +489,10 @@ public class DefaultValue {
       if (jsonObj.get("array_string_nullable") != null && !jsonObj.get("array_string_nullable").isJsonArray()) {
         throw new IllegalArgumentException(String.format("Expected the field `array_string_nullable` to be an array in the JSON string but got `%s`", jsonObj.get("array_string_nullable").toString()));
       }
+      // ensure the optional json data is an array if present
+      if (jsonObj.get("array_string_extension_nullable") != null && !jsonObj.get("array_string_extension_nullable").isJsonArray()) {
+        throw new IllegalArgumentException(String.format("Expected the field `array_string_extension_nullable` to be an array in the JSON string but got `%s`", jsonObj.get("array_string_extension_nullable").toString()));
+      }
       if ((jsonObj.get("string_nullable") != null && !jsonObj.get("string_nullable").isJsonNull()) && !jsonObj.get("string_nullable").isJsonPrimitive()) {
         throw new IllegalArgumentException(String.format("Expected the field `string_nullable` to be a primitive type in the JSON string but got `%s`", jsonObj.get("string_nullable").toString()));
       }

samples/client/echo_api/python-nextgen/docs/DefaultValue.md

@@ -11,6 +11,7 @@ Name | Type | Description | Notes
 **array_integer_default** | **List[int]** |  | [optional] [default to [1,3]]
 **array_string** | **List[str]** |  | [optional] 
 **array_string_nullable** | **List[str]** |  | [optional] 
+**array_string_extension_nullable** | **List[str]** |  | [optional] 
 **string_nullable** | **str** |  | [optional] 
 
 ## Example

samples/client/echo_api/python-nextgen/openapi_client/models/default_value.py

@@ -34,8 +34,9 @@ class DefaultValue(BaseModel):
     array_integer_default: Optional[List[StrictInt]] = None
     array_string: Optional[List[StrictStr]] = None
     array_string_nullable: Optional[List[StrictStr]] = None
+    array_string_extension_nullable: Optional[List[StrictStr]] = None
     string_nullable: Optional[StrictStr] = None
-    __properties = ["array_string_enum_ref_default", "array_string_enum_default", "array_string_default", "array_integer_default", "array_string", "array_string_nullable", "string_nullable"]
+    __properties = ["array_string_enum_ref_default", "array_string_enum_default", "array_string_default", "array_integer_default", "array_string", "array_string_nullable", "array_string_extension_nullable", "string_nullable"]
 
     @validator('array_string_enum_default')
     def array_string_enum_default_validate_enum(cls, v):
@@ -73,6 +74,10 @@ class DefaultValue(BaseModel):
         if self.array_string_nullable is None:
             _dict['array_string_nullable'] = None
 
+        # set to None if array_string_extension_nullable (nullable) is None
+        if self.array_string_extension_nullable is None:
+            _dict['array_string_extension_nullable'] = None
+
         # set to None if string_nullable (nullable) is None
         if self.string_nullable is None:
             _dict['string_nullable'] = None
@@ -95,6 +100,7 @@ class DefaultValue(BaseModel):
             "array_integer_default": obj.get("array_integer_default"),
             "array_string": obj.get("array_string"),
             "array_string_nullable": obj.get("array_string_nullable"),
+            "array_string_extension_nullable": obj.get("array_string_extension_nullable"),
             "string_nullable": obj.get("string_nullable")
         })
         return _obj