Add support for enums in error message

src/Assert.php

@@ -15,6 +15,9 @@
 use function array_unshift;
 use function call_user_func_array;
 use function end;
+use function enum_exists;
+use function function_exists;
+use function get_class;
 use function is_object;
 use function is_resource;
 use function is_string;
@@ -465,6 +468,10 @@ protected static function valueToString(mixed $value): string
                 return $value::class . ': ' . self::valueToString($value->format('c'));
             }
 
+            if (function_exists('enum_exists') && enum_exists(get_class($value))) {
+                return get_class($value) . '::' . $value->name;
+            }
+
             return $value::class;
         }
 

tests/Assert/AssertTest.php

@@ -15,6 +15,7 @@
 use SimpleSAML\Assert\Assert;
 use SimpleSAML\Assert\AssertionFailedException;
 use SimpleSAML\Test\Utils\TestClass;
+use SimpleSAML\Test\Utils\TestEnum;
 use stdClass;
 
 use function opendir;
@@ -143,13 +144,16 @@ public static function provideValue(): array
 
         $resource = opendir(sys_get_temp_dir());
 
+        $enum = TestEnum::PHPUnit;
+
         return [
             'null' => [null, 'null'],
             'true' => [true, 'true'],
             'false' => [false, 'false'],
             'array' => [[], 'array'],
             'Stringable' => [$stringable, 'SimpleSAML\Test\Utils\TestClass: "phpunit"'],
             'DateTime' => [$dateTime, 'DateTimeImmutable: "2000-01-01T00:00:00+00:00"'],
+            'Enum' => [$enum, 'SimpleSAML\Test\Utils\TestEnum::PHPUnit'],
             'object' => [$otherObject, 'stdClass'],
             'resource' => [$resource, 'resource'],
             'string' => ['string', '"string"'],

tests/Utils/TestEnum.php

@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SimpleSAML\Test\Utils;
+
+// Declare a simple enumeration
+enum TestEnum
+{
+    case PHPCS;
+    case PHPStan;
+    case PHPUnit;
+    case Psalm;
+}