From e8fb930da577ba4f4b369ef005f9c15ce78ea4bf Mon Sep 17 00:00:00 2001
From: Capelo <capelo@remote.com>
Date: Tue, 15 Jul 2025 17:12:19 +0100
Subject: [PATCH 1/2] fix: properly handle function as custom field properties

---
 src/field/schema.ts    | 7 ++++++-
 src/form.ts            | 4 ++--
 src/validation/util.ts | 1 +
 test/fields.test.ts    | 7 ++++++-
 4 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/field/schema.ts b/src/field/schema.ts
index a46c5070e..907fb488e 100644
--- a/src/field/schema.ts
+++ b/src/field/schema.ts
@@ -373,7 +373,12 @@ export function buildFieldSchema({
     return null
   }
 
-  const presentation = schema['x-jsf-presentation'] || {}
+  const presentation = {
+    // We need to use the original schema's presentation as a basis as there are some properties that can't be
+    // serialized (so they were not cloned)
+    ...(originalSchema['x-jsf-presentation'] || {}),
+    ...(schema['x-jsf-presentation'] || {}),
+  }
   const errorMessage = schema['x-jsf-errorMessage']
 
   // Get input type from presentation or fallback to schema type
diff --git a/src/form.ts b/src/form.ts
index 2a5308511..113344199 100644
--- a/src/form.ts
+++ b/src/form.ts
@@ -245,11 +245,11 @@ function buildFields(params: { schema: JsfObjectSchema, originalSchema: JsfObjec
 /**
  * Ensures that no forbidden options are given
  * @param options - The options to validate
- * @throws An error if any forbidden options are found
+ * Alerts to the console that the option is deprecated and not being considered
  */
 function validateOptions(options: CreateHeadlessFormOptions) {
   if (Object.prototype.hasOwnProperty.call(options, 'customProperties')) {
-    throw new Error('`customProperties` is a deprecated option and it\'s not supported on json-schema-form v1')
+    console.error('[json-schema-form] `customProperties` is a deprecated option and it\'s not supported on json-schema-form v1')
   }
 }
 
diff --git a/src/validation/util.ts b/src/validation/util.ts
index 40774128b..c0b386e4f 100644
--- a/src/validation/util.ts
+++ b/src/validation/util.ts
@@ -71,6 +71,7 @@ export function deepEqual(a: SchemaValue, b: SchemaValue): boolean {
 
 /**
  * Deep clones an object using structuredClone if available, otherwise falls back to JSON.parse/stringify approach.
+ * Please note: some properties might not be serializable (e.g. functions), so they will be lost in the clone.
  *
  * @param obj - The object to clone
  * @returns deep clone of the original object
diff --git a/test/fields.test.ts b/test/fields.test.ts
index 6f721592c..88ae85846 100644
--- a/test/fields.test.ts
+++ b/test/fields.test.ts
@@ -163,7 +163,10 @@ describe('fields', () => {
     })
   })
 
-  it('should handle custom x-jsf-presentation properties', () => {
+  it('should handle custom x-jsf-presentation properties, including functions', () => {
+    const customComponent = () => {
+      return null
+    }
     const schema: JsfSchema = {
       type: 'object',
       properties: {
@@ -174,6 +177,7 @@ describe('fields', () => {
             inputType: 'file',
             accept: '.pdf,.doc',
             maxFileSize: 5000000,
+            Component: customComponent,
           },
         },
       },
@@ -192,6 +196,7 @@ describe('fields', () => {
         required: false,
         accept: '.pdf,.doc',
         maxFileSize: 5000000,
+        Component: customComponent,
       },
     ])
   })

From aeb92a84930730acd8b62744746433f5b8fb29e1 Mon Sep 17 00:00:00 2001
From: Capelo <capelo@remote.com>
Date: Wed, 16 Jul 2025 09:34:58 +0100
Subject: [PATCH 2/2] fix tests

---
 test/fields/array.test.ts | 2 ++
 test/form.test.ts         | 9 +++++----
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/test/fields/array.test.ts b/test/fields/array.test.ts
index e647530d5..3ea59a0b3 100644
--- a/test/fields/array.test.ts
+++ b/test/fields/array.test.ts
@@ -217,6 +217,8 @@ describe('buildFieldArray', () => {
           isVisible: true,
           nameKey: 'title',
           required: false,
+          foo: 'bar',
+          bar: 'baz',
         },
       ],
       items: expect.any(Object),
diff --git a/test/form.test.ts b/test/form.test.ts
index b0885e270..4240dc3ba 100644
--- a/test/form.test.ts
+++ b/test/form.test.ts
@@ -1,5 +1,5 @@
 import type { JsfObjectSchema } from '../src/types'
-import { describe, expect, it } from '@jest/globals'
+import { describe, expect, it, jest } from '@jest/globals'
 import { createHeadlessForm } from '../src'
 
 describe('createHeadlessForm', () => {
@@ -16,9 +16,10 @@ describe('createHeadlessForm', () => {
     }
 
     it('should throw error when customProperties option is provided', () => {
-      expect(() => {
-        createHeadlessForm(basicSchema, { customProperties: {} } as any)
-      }).toThrow('`customProperties` is a deprecated option and it\'s not supported on json-schema-form v1')
+      // spy on console.error
+      const consoleErrorSpy = jest.spyOn(console, 'error').mockImplementation(() => {})
+      createHeadlessForm(basicSchema, { customProperties: {} } as any)
+      expect(consoleErrorSpy).toHaveBeenCalledWith('[json-schema-form] `customProperties` is a deprecated option and it\'s not supported on json-schema-form v1')
     })
 
     it('should not throw error when modifyConfig option is not provided', () => {