fix: traditional validation rule matches and differs

Match CI3 behaviros.

Author: kenjis

system/Validation/Rules.php

@@ -24,9 +24,10 @@ class Rules
     /**
      * The value does not match another field in $data.
      *
+     * @param string|null $str
      * @param array $data Other field/value pairs
      */
-    public function differs(?string $str, string $field, array $data): bool
+    public function differs($str, string $field, array $data): bool
     {
         if (strpos($field, '.') !== false) {
             return $str !== dot_array_search($field, $data);
@@ -177,15 +178,16 @@ public function less_than_equal_to(?string $str, string $max): bool
     /**
      * Matches the value of another field in $data.
      *
+     * @param string|null $str
      * @param array $data Other field/value pairs
      */
-    public function matches(?string $str, string $field, array $data): bool
+    public function matches($str, string $field, array $data): bool
     {
         if (strpos($field, '.') !== false) {
             return $str === dot_array_search($field, $data);
         }
 
-        return array_key_exists($field, $data) && $str === $data[$field];
+        return isset($data[$field]) ? ($str === $data[$field]) : false;
     }
 
     /**

tests/system/Validation/RulesTest.php

@@ -303,13 +303,13 @@ public static function provideMatches(): iterable
         yield from [
             'foo bar not exist'        => [[], false],
             'bar not exist'            => [['foo' => null], false],
-            'foo not exist'            => [['bar' => null], true], // Strict Rule: false
-            'foo bar null'             => [['foo' => null, 'bar' => null], true],
+            'foo not exist'            => [['bar' => null], false],
+            'foo bar null'             => [['foo' => null, 'bar' => null], false],
             'foo bar string match'     => [['foo' => 'match', 'bar' => 'match'], true],
             'foo bar string not match' => [['foo' => 'match', 'bar' => 'nope'], false],
-            'foo bar float match'      => [['foo' => 1.2, 'bar' => 1.2], false], // Strict Rule: true
+            'foo bar float match'      => [['foo' => 1.2, 'bar' => 1.2], true],
             'foo bar float not match'  => [['foo' => 1.2, 'bar' => 2.3], false],
-            'foo bar bool match'       => [['foo' => true, 'bar' => true], false], // Strict Rule: true
+            'foo bar bool match'       => [['foo' => true, 'bar' => true], true],
         ];
     }
 
@@ -348,9 +348,9 @@ public static function provideDiffers(): iterable
             'foo bar null'             => [['foo' => null, 'bar' => null], false],
             'foo bar string match'     => [['foo' => 'match', 'bar' => 'match'], false],
             'foo bar string not match' => [['foo' => 'match', 'bar' => 'nope'], true],
-            'foo bar float match'      => [['foo' => 1.2, 'bar' => 1.2], true], // Strict Rule: false
+            'foo bar float match'      => [['foo' => 1.2, 'bar' => 1.2], false],
             'foo bar float not match'  => [['foo' => 1.2, 'bar' => 2.3], true],
-            'foo bar bool match'       => [['foo' => true, 'bar' => true], true], // Strict Rule: false
+            'foo bar bool match'       => [['foo' => true, 'bar' => true], false],
         ];
     }