[10.x] add missing method to message bag class

src/Illuminate/Support/MessageBag.php

@@ -159,6 +159,19 @@ public function hasAny($keys = [])
         return false;
     }
 
+    /**
+     * Determine if messages don't exist for all of the given keys.
+     *
+     * @param  array|string|null  $key
+     * @return bool
+     */
+    public function missing($key)
+    {
+        $keys = is_array($key) ? $key : func_get_args();
+
+        return ! $this->hasAny($keys);
+    }
+
     /**
      * Get the first message from the message bag for a given key.
      *

tests/Support/SupportMessageBagTest.php

@@ -115,6 +115,19 @@ public function testHasIndicatesExistence()
         $this->assertFalse($container->has('bar'));
     }
 
+    public function testMissingIndicatesNonExistence()
+    {
+        $container = new MessageBag;
+        $container->setFormat(':message');
+        $container->add('foo', 'bar');
+        $this->assertFalse($container->missing('foo'));
+        $this->assertFalse($container->missing(['foo', 'baz']));
+        $this->assertFalse($container->missing('foo', 'baz'));
+        $this->assertTrue($container->missing('baz'));
+        $this->assertTrue($container->missing(['baz', 'biz']));
+        $this->assertTrue($container->missing('baz', 'biz'));
+    }
+
     public function testAddIf()
     {
         $container = new MessageBag;