[8.x] Fixes middleware() not accepting Stringable (#39449)

* Fixes `middleware()` not accepting Stringable.

* Reverses the string to array check.

* Removed redundant not-array checks for middleware attribute.

* Forces the middleware registration as array.

Author: DarkGhostHunter

src/Illuminate/Routing/PendingResourceRegistration.php

@@ -149,12 +149,10 @@ public function parameter($previous, $new)
      */
     public function middleware($middleware)
     {
-        if (! is_string($middleware)) {
-            $middleware = Arr::wrap($middleware);
+        $middleware = Arr::wrap($middleware);
 
-            foreach ($middleware as $key => $value) {
-                $middleware[$key] = (string) $value;
-            }
+        foreach ($middleware as $key => $value) {
+            $middleware[$key] = (string) $value;
         }
 
         $this->options['middleware'] = $middleware;

src/Illuminate/Routing/Route.php

@@ -1025,10 +1025,14 @@ public function middleware($middleware = null)
             return (array) ($this->action['middleware'] ?? []);
         }
 
-        if (is_string($middleware)) {
+        if (! is_array($middleware)) {
             $middleware = func_get_args();
         }
 
+        foreach ($middleware as $index => $value) {
+            $middleware[$index] = (string) $value;
+        }
+
         $this->action['middleware'] = array_merge(
             (array) ($this->action['middleware'] ?? []), $middleware
         );

src/Illuminate/Routing/RouteRegistrar.php

@@ -93,9 +93,7 @@ public function attribute($key, $value)
             throw new InvalidArgumentException("Attribute [{$key}] does not exist.");
         }
 
-        if ($key === 'middleware' && ! is_string($value)) {
-            $value = Arr::wrap($value);
-
+        if ($key === 'middleware') {
             foreach ($value as $index => $middleware) {
                 $value[$index] = (string) $middleware;
             }

tests/Routing/RouteRegistrarTest.php

@@ -79,6 +79,24 @@ public function __toString()
         $this->assertSame(['one'], $this->getRoute()->middleware());
     }
 
+    public function testMiddlewareAsStringableObjectOnRouteInstance()
+    {
+        $one = new class implements Stringable
+        {
+            public function __toString()
+            {
+                return 'one';
+            }
+        };
+
+        $this->router->get('users', function () {
+            return 'all-users';
+        })->middleware($one);
+
+        $this->seeResponse('all-users', Request::create('users', 'GET'));
+        $this->assertSame(['one'], $this->getRoute()->middleware());
+    }
+
     public function testMiddlewareAsArrayWithStringables()
     {
         $one = new class implements Stringable