From 0ba85bc1d00281c79f8623186b2e5ba6a3ec2929 Mon Sep 17 00:00:00 2001
From: Steve Boyd <emteknetnz@gmail.com>
Date: Tue, 14 May 2024 12:43:59 +1200
Subject: [PATCH] API Deprecate passing non-arrays to FieldList methods

---
 src/Forms/FieldList.php | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/Forms/FieldList.php b/src/Forms/FieldList.php
index 7e8a80cd1..85143cf13 100644
--- a/src/Forms/FieldList.php
+++ b/src/Forms/FieldList.php
@@ -3,6 +3,7 @@
 namespace SilverStripe\Forms;
 
 use SilverStripe\ORM\ArrayList;
+use SilverStripe\Dev\Deprecation;
 
 /**
  * A list designed to hold form field instances.
@@ -218,6 +219,10 @@ class FieldList extends ArrayList
      */
     public function addFieldsToTab($tabName, $fields, $insertBefore = null)
     {
+        if (!is_array($fields)) {
+            Deprecation::notice('5.3.0', '$fields will need to be passed as an array in CMS 6', Deprecation::SCOPE_METHOD);
+        }
+
         $this->flushFieldsCache();
 
         // Find the tab
@@ -270,6 +275,10 @@ class FieldList extends ArrayList
      */
     public function removeFieldsFromTab($tabName, $fields)
     {
+        if (!is_array($fields)) {
+            Deprecation::notice('5.3.0', '$fields will need to be passed as an array in CMS 6', Deprecation::SCOPE_METHOD);
+        }
+
         $this->flushFieldsCache();
 
         // Find the tab