From 78aff1ed72ab28afb7b4e0060c6ce82fbe50415c Mon Sep 17 00:00:00 2001
From: SBNTT <bysebastien@gmail.com>
Date: Mon, 4 May 2026 15:10:42 +0200
Subject: [PATCH 1/2] nullable enum value

---
 src/Capability/Discovery/SchemaGenerator.php | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Capability/Discovery/SchemaGenerator.php b/src/Capability/Discovery/SchemaGenerator.php
index 6366fd49..8ca222e3 100644
--- a/src/Capability/Discovery/SchemaGenerator.php
+++ b/src/Capability/Discovery/SchemaGenerator.php
@@ -375,6 +375,7 @@ private function applyEnumConstraints(array $paramSchema, array $paramInfo): arr
             if ($jsonBackingType) {
                 if (isset($paramSchema['type']) && \is_array($paramSchema['type']) && \in_array('null', $paramSchema['type'])) {
                     $paramSchema['type'] = ['null', $jsonBackingType];
+                    $paramSchema['enum'][] = null;
                 } else {
                     $paramSchema['type'] = $jsonBackingType;
                 }
@@ -384,6 +385,7 @@ private function applyEnumConstraints(array $paramSchema, array $paramInfo): arr
             $paramSchema['enum'] = array_column($enumClass::cases(), 'name');
             if (isset($paramSchema['type']) && \is_array($paramSchema['type']) && \in_array('null', $paramSchema['type'])) {
                 $paramSchema['type'] = ['null', 'string'];
+                $paramSchema['enum'][] = null;
             } else {
                 $paramSchema['type'] = 'string';
             }

From d1c38a1b47f59f80f638061862d2a63480511777 Mon Sep 17 00:00:00 2001
From: SBNTT <bysebastien@gmail.com>
Date: Mon, 4 May 2026 15:22:07 +0200
Subject: [PATCH 2/2] fix tests

---
 src/Capability/Discovery/SchemaGenerator.php            | 4 ++--
 tests/Unit/Capability/Discovery/SchemaGeneratorTest.php | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/Capability/Discovery/SchemaGenerator.php b/src/Capability/Discovery/SchemaGenerator.php
index 8ca222e3..04ee08f6 100644
--- a/src/Capability/Discovery/SchemaGenerator.php
+++ b/src/Capability/Discovery/SchemaGenerator.php
@@ -374,7 +374,7 @@ private function applyEnumConstraints(array $paramSchema, array $paramInfo): arr
 
             if ($jsonBackingType) {
                 if (isset($paramSchema['type']) && \is_array($paramSchema['type']) && \in_array('null', $paramSchema['type'])) {
-                    $paramSchema['type'] = ['null', $jsonBackingType];
+                    $paramSchema['type'] = [$jsonBackingType, 'null'];
                     $paramSchema['enum'][] = null;
                 } else {
                     $paramSchema['type'] = $jsonBackingType;
@@ -384,7 +384,7 @@ private function applyEnumConstraints(array $paramSchema, array $paramInfo): arr
             // Non-backed enum - use names as enum values
             $paramSchema['enum'] = array_column($enumClass::cases(), 'name');
             if (isset($paramSchema['type']) && \is_array($paramSchema['type']) && \in_array('null', $paramSchema['type'])) {
-                $paramSchema['type'] = ['null', 'string'];
+                $paramSchema['type'] = ['string', 'null'];
                 $paramSchema['enum'][] = null;
             } else {
                 $paramSchema['type'] = 'string';
diff --git a/tests/Unit/Capability/Discovery/SchemaGeneratorTest.php b/tests/Unit/Capability/Discovery/SchemaGeneratorTest.php
index 299e9854..c92121e6 100644
--- a/tests/Unit/Capability/Discovery/SchemaGeneratorTest.php
+++ b/tests/Unit/Capability/Discovery/SchemaGeneratorTest.php
@@ -197,7 +197,7 @@ public function testGeneratesCorrectSchemaForEnumParameters(): void
         $this->assertEquals(['type' => 'string', 'description' => 'Backed string enum', 'enum' => ['A', 'B']], $schema['properties']['stringEnum']);
         $this->assertEquals(['type' => 'integer', 'description' => 'Backed int enum', 'enum' => [1, 2]], $schema['properties']['intEnum']);
         $this->assertEquals(['type' => 'string', 'description' => 'Unit enum', 'enum' => ['Yes', 'No']], $schema['properties']['unitEnum']);
-        $this->assertEquals(['type' => ['null', 'string'], 'enum' => ['A', 'B'], 'default' => null], $schema['properties']['nullableEnum']);
+        $this->assertEquals(['type' => ['string', 'null'], 'enum' => ['A', 'B', null], 'default' => null], $schema['properties']['nullableEnum']);
         $this->assertEquals(['type' => 'integer', 'enum' => [1, 2], 'default' => 1], $schema['properties']['enumWithDefault']);
         $this->assertEqualsCanonicalizing(['stringEnum', 'intEnum', 'unitEnum'], $schema['required']);
     }