From 5aaad620e960e9726ee5d44dfd2cd76e10bdc4f0 Mon Sep 17 00:00:00 2001
From: goncharu <goncharu@adobe.com>
Date: Fri, 11 Sep 2026 18:12:37 -0500
Subject: [PATCH 1/2] Detect REQUIRED_ARG_ADDED when the old field had no prior
 arguments

---
 CHANGELOG.md                              |  4 ++
 src/Utils/BreakingChangesFinder.php       | 47 ++++++++++++-----------
 tests/Utils/BreakingChangesFinderTest.php | 42 ++++++++++++++++++++
 3 files changed, 70 insertions(+), 23 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 597124776..784f62506 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,10 @@ You can find and compare releases at the [GitHub release page](https://github.co
 
 ## Unreleased
 
+### Fixed
+
+- Detect `REQUIRED_ARG_ADDED` in `BreakingChangesFinder::findArgChanges()` when the old field had no prior arguments https://github.com/webonyx/graphql-php/pull/TODO
+
 ## v15.37.2
 
 ### Changed
diff --git a/src/Utils/BreakingChangesFinder.php b/src/Utils/BreakingChangesFinder.php
index 528cfc8fa..b786d2eb4 100644
--- a/src/Utils/BreakingChangesFinder.php
+++ b/src/Utils/BreakingChangesFinder.php
@@ -535,33 +535,34 @@ public static function findArgChanges(
                             'description' => "{$typeName}.{$fieldName} arg {$oldArgDef->name} was removed",
                         ];
                     }
+                }
 
-                    // Check if arg was added to the field
-                    foreach ($newTypeFields[$fieldName]->args as $newTypeFieldArgDef) {
-                        $oldArgDef = null;
-                        foreach ($oldTypeFields[$fieldName]->args as $oldArg) {
-                            if ($oldArg->name === $newTypeFieldArgDef->name) {
-                                $oldArgDef = $oldArg;
-                            }
+                // Check if arg was added to the field. This must run even when the old
+                // field had zero args, so it lives outside the loop over $oldField->args.
+                foreach ($newTypeFields[$fieldName]->args as $newTypeFieldArgDef) {
+                    $oldArgDef = null;
+                    foreach ($oldTypeFields[$fieldName]->args as $oldArg) {
+                        if ($oldArg->name === $newTypeFieldArgDef->name) {
+                            $oldArgDef = $oldArg;
                         }
+                    }
 
-                        if ($oldArgDef !== null) {
-                            continue;
-                        }
+                    if ($oldArgDef !== null) {
+                        continue;
+                    }
 
-                        $newTypeName = $newType->name;
-                        $newArgName = $newTypeFieldArgDef->name;
-                        if ($newTypeFieldArgDef->isRequired()) {
-                            $breakingChanges[] = [
-                                'type' => self::BREAKING_CHANGE_REQUIRED_ARG_ADDED,
-                                'description' => "A required arg {$newArgName} on {$newTypeName}.{$fieldName} was added",
-                            ];
-                        } else {
-                            $dangerousChanges[] = [
-                                'type' => self::DANGEROUS_CHANGE_OPTIONAL_ARG_ADDED,
-                                'description' => "An optional arg {$newArgName} on {$newTypeName}.{$fieldName} was added",
-                            ];
-                        }
+                    $newTypeName = $newType->name;
+                    $newArgName = $newTypeFieldArgDef->name;
+                    if ($newTypeFieldArgDef->isRequired()) {
+                        $breakingChanges[] = [
+                            'type' => self::BREAKING_CHANGE_REQUIRED_ARG_ADDED,
+                            'description' => "A required arg {$newArgName} on {$newTypeName}.{$fieldName} was added",
+                        ];
+                    } else {
+                        $dangerousChanges[] = [
+                            'type' => self::DANGEROUS_CHANGE_OPTIONAL_ARG_ADDED,
+                            'description' => "An optional arg {$newArgName} on {$newTypeName}.{$fieldName} was added",
+                        ];
                     }
                 }
             }
diff --git a/tests/Utils/BreakingChangesFinderTest.php b/tests/Utils/BreakingChangesFinderTest.php
index 1fe895d88..9b3a4ba64 100644
--- a/tests/Utils/BreakingChangesFinderTest.php
+++ b/tests/Utils/BreakingChangesFinderTest.php
@@ -855,6 +855,48 @@ public function testShouldDetectIfANonNullFieldArgumentWasAdded(): void
         );
     }
 
+    public function testShouldDetectIfANonNullFieldArgumentWasAddedToAFieldWithNoPriorArgs(): void
+    {
+        $oldType = new ObjectType([
+            'name' => 'Type1',
+            'fields' => [
+                'field1' => [
+                    'type' => Type::string(),
+                    'args' => [],
+                ],
+            ],
+        ]);
+        $newType = new ObjectType([
+            'name' => 'Type1',
+            'fields' => [
+                'field1' => [
+                    'type' => Type::string(),
+                    'args' => [
+                        'newRequiredArg' => Type::nonNull(Type::string()),
+                    ],
+                ],
+            ],
+        ]);
+        $oldSchema = new Schema([
+            'query' => $this->queryType,
+            'types' => [$oldType],
+        ]);
+        $newSchema = new Schema([
+            'query' => $this->queryType,
+            'types' => [$newType],
+        ]);
+
+        self::assertSame(
+            [
+                [
+                    'type' => BreakingChangesFinder::BREAKING_CHANGE_REQUIRED_ARG_ADDED,
+                    'description' => 'A required arg newRequiredArg on Type1.field1 was added',
+                ],
+            ],
+            BreakingChangesFinder::findArgChanges($oldSchema, $newSchema)['breakingChanges']
+        );
+    }
+
     /** @see it('should not flag args with the same type signature as breaking') */
     public function testShouldNotFlagArgsWithTheSameTypeSignatureAsBreaking(): void
     {

From 4474cc946f1c4fdc29515bb112769b69a9548ed3 Mon Sep 17 00:00:00 2001
From: goncharu <goncharu@adobe.com>
Date: Fri, 11 Sep 2026 18:21:20 -0500
Subject: [PATCH 2/2] Add PR link to changelog entry

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 784f62506..ad69a6677 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,7 +11,7 @@ You can find and compare releases at the [GitHub release page](https://github.co
 
 ### Fixed
 
-- Detect `REQUIRED_ARG_ADDED` in `BreakingChangesFinder::findArgChanges()` when the old field had no prior arguments https://github.com/webonyx/graphql-php/pull/TODO
+- Detect `REQUIRED_ARG_ADDED` in `BreakingChangesFinder::findArgChanges()` when the old field had no prior arguments https://github.com/webonyx/graphql-php/pull/1976
 
 ## v15.37.2