add custom field support on post method at sub-resource level

src/main/java/com/chargebee/sdk/java/v4/JavaV4.java

@@ -4,7 +4,6 @@
 import com.chargebee.sdk.FileOp;
 import com.chargebee.sdk.Language;
 import com.chargebee.sdk.java.v4.builder.*;
-
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;

src/main/java/com/chargebee/sdk/java/v4/builder/PostRequestParamsBuilder.java

@@ -198,6 +198,11 @@ private Model createSubModel(String simpleNameSnake, String fullPathSnake, Schem
     subModel.setFields(getFields(schema, fullPathSnake, isCompositeArray));
     subModel.setEnumFields(getEnumFields(schema, isCompositeArray));
     subModel.setSubModels(getSubModels(schema, fullPathSnake));
+
+    // Check for custom fields and consent fields support at sub-params level
+    subModel.setCustomFieldsSupported(SchemaUtil.isCustomFieldsSupported(schema));
+    subModel.setConsentFieldsSupported(SchemaUtil.isConsentFieldsSupported(schema));
+
     return subModel;
   }
 

src/test/java/com/chargebee/sdk/java/v4/builder/GetRequestParamsBuilderTest.java

@@ -1620,13 +1620,15 @@ void shouldGenerateCustomFieldMethodWhenSupported() throws IOException {
 
       FileOp.WriteString writeOp = findWriteOp(fileOps, "CustomerListParams.java");
       assertThat(writeOp.fileContent)
-          .contains("public CustomFieldSelector<CustomerListBuilder> customField(String fieldName)");
+          .contains(
+              "public CustomFieldSelector<CustomerListBuilder> customField(String fieldName)");
       assertThat(writeOp.fileContent)
           .contains("return new CustomFieldSelector<>(fieldName, this, queryParams)");
     }
 
     @Test
-    @DisplayName("Should not generate customField method when x-cb-is-custom-fields-supported is false")
+    @DisplayName(
+        "Should not generate customField method when x-cb-is-custom-fields-supported is false")
     void shouldNotGenerateCustomFieldMethodWhenNotSupported() throws IOException {
       Operation getOperation = createGetOperation("customer", "list");
       getOperation.getExtensions().put(Extension.IS_CUSTOM_FIELDS_SUPPORTED, false);
@@ -1674,8 +1676,7 @@ void shouldImportCustomFieldSelectorWhenSupported() throws IOException {
       FileOp.WriteString writeOp = findWriteOp(fileOps, "SubscriptionListParams.java");
       assertThat(writeOp.fileContent)
           .contains("import com.chargebee.v4.filters.CustomFieldSelector;");
-      assertThat(writeOp.fileContent)
-          .contains("import com.chargebee.v4.filters.BooleanFilter;");
+      assertThat(writeOp.fileContent).contains("import com.chargebee.v4.filters.BooleanFilter;");
     }
 
     @Test
@@ -1697,11 +1698,13 @@ void shouldGenerateCorrectBuilderTypeForDifferentOperations() throws IOException
 
       FileOp.WriteString customerWriteOp = findWriteOp(fileOps, "CustomerListParams.java");
       assertThat(customerWriteOp.fileContent)
-          .contains("public CustomFieldSelector<CustomerListBuilder> customField(String fieldName)");
+          .contains(
+              "public CustomFieldSelector<CustomerListBuilder> customField(String fieldName)");
 
       FileOp.WriteString subscriptionWriteOp = findWriteOp(fileOps, "SubscriptionListParams.java");
       assertThat(subscriptionWriteOp.fileContent)
-          .contains("public CustomFieldSelector<SubscriptionListBuilder> customField(String fieldName)");
+          .contains(
+              "public CustomFieldSelector<SubscriptionListBuilder> customField(String fieldName)");
     }
 
     @Test
@@ -1719,7 +1722,8 @@ void shouldGenerateCustomFieldMethodWithJavadoc() throws IOException {
       FileOp.WriteString writeOp = findWriteOp(fileOps, "CustomerListParams.java");
       assertThat(writeOp.fileContent).contains("Create a filter for a custom field");
       assertThat(writeOp.fileContent).contains("@param fieldName the custom field name");
-      assertThat(writeOp.fileContent).contains("@return CustomFieldSelector for choosing filter type");
+      assertThat(writeOp.fileContent)
+          .contains("@return CustomFieldSelector for choosing filter type");
     }
 
     @Test
@@ -1742,7 +1746,8 @@ void shouldHandleCustomFieldSupportWithOtherFeatures() throws IOException {
       FileOp.WriteString writeOp = findWriteOp(fileOps, "CustomerListParams.java");
       // Verify customField method is generated
       assertThat(writeOp.fileContent)
-          .contains("public CustomFieldSelector<CustomerListBuilder> customField(String fieldName)");
+          .contains(
+              "public CustomFieldSelector<CustomerListBuilder> customField(String fieldName)");
       // Verify other features are still generated
       assertThat(writeOp.fileContent).contains("public FirstNameFilter firstName()");
       assertThat(writeOp.fileContent).contains("public CreatedAtFilter createdAt()");

src/test/java/com/chargebee/sdk/java/v4/builder/PostRequestParamsBuilderCustomFieldsTest.java

@@ -239,6 +239,104 @@ void shouldHandleCustomFieldsExtensionSetToFalse() throws IOException {
       FileOp.WriteString writeOp = findWriteOp(fileOps, "TestCreateParams.java");
       assertThat(writeOp.fileContent).doesNotContain("customField");
     }
+
+    @Test
+    @DisplayName(
+        "Should add custom field methods to sub-params when x-cb-is-custom-fields-supported is true"
+            + " at sub-params level")
+    void shouldAddCustomFieldMethodsToSubParamsWithCustomFieldsExtension() throws IOException {
+      // Create a nested object schema (billing_address) with custom fields support
+      ObjectSchema billingAddressSchema = new ObjectSchema();
+      billingAddressSchema.addProperty("line1", new StringSchema());
+      billingAddressSchema.addProperty("city", new StringSchema());
+      billingAddressSchema.addExtension("x-cb-is-custom-fields-supported", true);
+
+      // Parent request schema without custom fields support
+      ObjectSchema requestSchema = new ObjectSchema();
+      requestSchema.addProperty("first_name", new StringSchema());
+      requestSchema.addProperty("billing_address", billingAddressSchema);
+
+      MediaType mediaType = new MediaType();
+      mediaType.setSchema(requestSchema);
+
+      Content content = new Content();
+      content.addMediaType("application/x-www-form-urlencoded", mediaType);
+
+      RequestBody requestBody = new RequestBody();
+      requestBody.setContent(content);
+
+      Operation postOp = new Operation();
+      postOp.setOperationId("create_customer");
+      postOp.addExtension(Extension.SDK_METHOD_NAME, "create");
+      postOp.addExtension(Extension.RESOURCE_ID, "customer");
+      postOp.setRequestBody(requestBody);
+
+      PathItem pathItem = new PathItem();
+      pathItem.setPost(postOp);
+
+      Paths paths = new Paths();
+      paths.addPathItem("/customers", pathItem);
+      openAPI.setPaths(paths);
+
+      paramsBuilder.withOutputDirectoryPath(outputPath).withTemplate(mockTemplate);
+
+      List<FileOp> fileOps = paramsBuilder.build(openAPI);
+
+      FileOp.WriteString writeOp = findWriteOp(fileOps, "CustomerCreateParams.java");
+      // Parent should NOT have custom fields
+      assertThat(writeOp.fileContent).doesNotContain("public CustomerCreateBuilder customField(");
+      // Sub-params (BillingAddress) should have custom fields
+      assertThat(writeOp.fileContent).contains("public BillingAddressBuilder customField(");
+      assertThat(writeOp.fileContent).contains("public BillingAddressBuilder customFields(");
+    }
+
+    @Test
+    @DisplayName(
+        "Should not add custom field methods to sub-params without x-cb-is-custom-fields-supported")
+    void shouldNotAddCustomFieldMethodsToSubParamsWithoutExtension() throws IOException {
+      // Create a nested object schema (billing_address) without custom fields support
+      ObjectSchema billingAddressSchema = new ObjectSchema();
+      billingAddressSchema.addProperty("line1", new StringSchema());
+      billingAddressSchema.addProperty("city", new StringSchema());
+
+      // Parent request schema with custom fields support
+      ObjectSchema requestSchema = new ObjectSchema();
+      requestSchema.addProperty("first_name", new StringSchema());
+      requestSchema.addProperty("billing_address", billingAddressSchema);
+      requestSchema.addExtension("x-cb-is-custom-fields-supported", true);
+
+      MediaType mediaType = new MediaType();
+      mediaType.setSchema(requestSchema);
+
+      Content content = new Content();
+      content.addMediaType("application/x-www-form-urlencoded", mediaType);
+
+      RequestBody requestBody = new RequestBody();
+      requestBody.setContent(content);
+
+      Operation postOp = new Operation();
+      postOp.setOperationId("create_customer");
+      postOp.addExtension(Extension.SDK_METHOD_NAME, "create");
+      postOp.addExtension(Extension.RESOURCE_ID, "customer");
+      postOp.setRequestBody(requestBody);
+
+      PathItem pathItem = new PathItem();
+      pathItem.setPost(postOp);
+
+      Paths paths = new Paths();
+      paths.addPathItem("/customers", pathItem);
+      openAPI.setPaths(paths);
+
+      paramsBuilder.withOutputDirectoryPath(outputPath).withTemplate(mockTemplate);
+
+      List<FileOp> fileOps = paramsBuilder.build(openAPI);
+
+      FileOp.WriteString writeOp = findWriteOp(fileOps, "CustomerCreateParams.java");
+      // Parent should have custom fields
+      assertThat(writeOp.fileContent).contains("public CustomerCreateBuilder customField(");
+      // Sub-params (BillingAddress) should NOT have custom fields
+      assertThat(writeOp.fileContent).doesNotContain("public BillingAddressBuilder customField(");
+    }
   }
 
   private FileOp.WriteString findWriteOp(List<FileOp> fileOps, String fileName) {