update: Added list rule helper

Author: erik-perri

src/Rule.php

@@ -631,6 +631,14 @@ public static function json(): string
         return 'json';
     }
 
+    /**
+     * The field under validation must be a list style array.
+     */
+    public static function list(): string
+    {
+        return 'list';
+    }
+
     /**
      * The field under validation must be lowercase.
      *

src/RuleSet.php

@@ -715,6 +715,14 @@ public function json(): self
         return $this->rule(Rule::json());
     }
 
+    /**
+     * The field under validation must be a list style array.
+     */
+    public function list(): self
+    {
+        return $this->rule(Rule::list());
+    }
+
     /**
      * The field under validation must be lowercase.
      *

tests/Unit/RuleTest.php

@@ -1226,6 +1226,21 @@ public static function ruleDataProvider(): array
                 'rules' => fn() => RuleSet::create()->json(),
                 'fails' => true,
             ],
+            'list valid' => [
+                'data' => ['a', 'b', 'c'],
+                'rules' => fn() => RuleSet::create()->list(),
+                'fails' => false,
+            ],
+            'list invalid array' => [
+                'data' => ['field' => ['a' => 'A', 'b' => 'B', 'c' => 'C']],
+                'rules' => fn() => ['field' => RuleSet::create()->list()],
+                'fails' => true,
+            ],
+            'list invalid string' => [
+                'data' => 'a,b,c',
+                'rules' => fn() => RuleSet::create()->list(),
+                'fails' => true,
+            ],
             'lowercase valid' => [
                 'data' => 'lowercase',
                 'rules' => fn() => RuleSet::create()->lowercase(),