Fix regex for single digits

Author: tvdijen

src/Assert/PositiveIntegerTrait.php

@@ -12,7 +12,7 @@
 trait PositiveIntegerTrait
 {
     /** @var string */
-    private static string $positiveInteger_regex = '/^[+]?(\d+[1-9]$)$/D';
+    private static string $positiveInteger_regex = '/^[+]?(\d*[1-9]$)$/D';
 
 
     /**

tests/Assert/PositiveIntegerTest.php

@@ -43,6 +43,7 @@ public static function providePositiveInteger(): array
             'empty' => [false, ''],
             'valid positive integer' => [true, '123456'],
             'valid signed positive integer' => [true, '+123456'],
+            'valid single digit' => [true, '3'],
             'invalid zero' => [false, '0'],
             'valid negative leading zeros' => [true, '0000000000000000000005'],
             'invalid with fractional' => [false, '1.'],

tests/Type/PositiveIntegerValueTest.php

@@ -45,6 +45,7 @@ public static function providePositiveInteger(): array
             'valid signed positive integer' => [true, '+123456'],
             'invalid zero' => [false, '0'],
             'valid negative leading zeros' => [true, '0000000000000000000005'],
+            'valid single digit' => [true, '3'],
             'valid with whitespace collapse' => [true, " 1 234 \n"],
             'invalid with fractional' => [false, '1.'],
             'invalid negative' => [false, '-1234'],