Fixed did not support multiple tag headers

Author: Toflar

src/Psr6Store.php

@@ -231,7 +231,11 @@ public function write(Request $request, Response $response)
         // Tags
         $tags = [];
         if ($response->headers->has($this->options['cache_tags_header'])) {
-            $tags = explode(',', $response->headers->get($this->options['cache_tags_header']));
+            foreach ($response->headers->get($this->options['cache_tags_header'], '', false) as $header) {
+                foreach (explode(',', $header) as $tag) {
+                    $tags[] = $tag;
+                }
+            }
         }
 
         // Prune expired entries on file system if needed

tests/Psr6StoreTest.php

@@ -230,6 +230,21 @@ public function testWriteAddsTags()
         $this->assertFalse($this->getCache()->getItem($cacheKey)->isHit());
     }
 
+    public function testWriteAddsTagsWithMultipleHeaders()
+    {
+        $request = Request::create('/');
+        $response = new Response('hello world', 200);
+        $response->headers->set('Cache-Tags', ['foobar,other tag', 'some,more', 'tags', 'split,over', 'multiple-headers']);
+
+        $cacheKey = $this->store->getCacheKey($request);
+
+        $this->store->write($request, $response);
+
+        $this->assertTrue($this->getCache()->getItem($cacheKey)->isHit());
+        $this->assertTrue($this->store->invalidateTags(['multiple-headers']));
+        $this->assertFalse($this->getCache()->getItem($cacheKey)->isHit());
+    }
+
     public function testInvalidateTagsThrowsExceptionIfWrongCacheAdapterProvided()
     {
         $this->expectException(\RuntimeException::class);