Fix middleware "SetCacheHeaders" with file responses (#44063)

* Fix test is content empty when it is a file response because in this case, it is always empty

* add test for cache header with file

Author: clementbirkle

src/Illuminate/Http/Middleware/SetCacheHeaders.php

@@ -4,6 +4,7 @@
 
 use Closure;
 use Illuminate\Support\Carbon;
+use Symfony\Component\HttpFoundation\BinaryFileResponse;
 
 class SetCacheHeaders
 {
@@ -21,7 +22,7 @@ public function handle($request, Closure $next, $options = [])
     {
         $response = $next($request);
 
-        if (! $request->isMethodCacheable() || ! $response->getContent()) {
+        if (! $request->isMethodCacheable() || (! $response->getContent() && ! $response instanceof BinaryFileResponse)) {
             return $response;
         }
 

tests/Http/Middleware/CacheTest.php

@@ -8,6 +8,7 @@
 use Illuminate\Support\Carbon;
 use InvalidArgumentException;
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\HttpFoundation\BinaryFileResponse;
 
 class CacheTest extends TestCase
 {
@@ -33,6 +34,16 @@ public function testDoNotSetHeaderWhenNoContent()
         $this->assertNull($response->getEtag());
     }
 
+    public function testSetHeaderToFileEvenWithNoContent()
+    {
+        $response = (new Cache)->handle(new Request, function ()  {
+            $filePath = __DIR__.'/../fixtures/test.txt';
+            return new BinaryFileResponse($filePath);
+        }, 'max_age=120;s_maxage=60');
+
+        $this->assertNotNull($response->getMaxAge());
+    }
+
     public function testAddHeaders()
     {
         $response = (new Cache)->handle(new Request, function () {