From c2c03e050fad47a77afbe0437e2e76b58f581a19 Mon Sep 17 00:00:00 2001
From: Lars Strojny <lars.strojny@internations.org>
Date: Thu, 17 Sep 2020 11:19:24 +0200
Subject: [PATCH] [Cache] Allow cache tags to be objects implementing
 __toString()

---
 src/Symfony/Component/Cache/CacheItem.php     |  5 ++--
 .../Component/Cache/Tests/CacheItemTest.php   |  5 +++-
 .../Cache/Tests/Fixtures/StringableTag.php    | 30 +++++++++++++++++++
 3 files changed, 37 insertions(+), 3 deletions(-)
 create mode 100644 src/Symfony/Component/Cache/Tests/Fixtures/StringableTag.php

diff --git a/src/Symfony/Component/Cache/CacheItem.php b/src/Symfony/Component/Cache/CacheItem.php
index 7245fe8207..3de8ddc81c 100644
--- a/src/Symfony/Component/Cache/CacheItem.php
+++ b/src/Symfony/Component/Cache/CacheItem.php
@@ -119,9 +119,10 @@ final class CacheItem implements ItemInterface
             $tags = [$tags];
         }
         foreach ($tags as $tag) {
-            if (!\is_string($tag)) {
-                throw new InvalidArgumentException(sprintf('Cache tag must be string, "%s" given.', \is_object($tag) ? \get_class($tag) : \gettype($tag)));
+            if (!\is_string($tag) && !(\is_object($tag) && method_exists($tag, '__toString'))) {
+                throw new InvalidArgumentException(sprintf('Cache tag must be string or object that implements __toString(), "%s" given.', \is_object($tag) ? \get_class($tag) : \gettype($tag)));
             }
+            $tag = (string) $tag;
             if (isset($this->newMetadata[self::METADATA_TAGS][$tag])) {
                 continue;
             }
diff --git a/src/Symfony/Component/Cache/Tests/CacheItemTest.php b/src/Symfony/Component/Cache/Tests/CacheItemTest.php
index 3b756f571f..01914e4a36 100644
--- a/src/Symfony/Component/Cache/Tests/CacheItemTest.php
+++ b/src/Symfony/Component/Cache/Tests/CacheItemTest.php
@@ -13,6 +13,7 @@ namespace Symfony\Component\Cache\Tests;
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Cache\CacheItem;
+use Symfony\Component\Cache\Tests\Fixtures\StringableTag;
 
 class CacheItemTest extends TestCase
 {
@@ -61,9 +62,11 @@ class CacheItemTest extends TestCase
 
         $this->assertSame($item, $item->tag('foo'));
         $this->assertSame($item, $item->tag(['bar', 'baz']));
+        $this->assertSame($item, $item->tag(new StringableTag('qux')));
+        $this->assertSame($item, $item->tag([new StringableTag('quux'), new StringableTag('quuux')]));
 
         (\Closure::bind(function () use ($item) {
-            $this->assertSame(['foo' => 'foo', 'bar' => 'bar', 'baz' => 'baz'], $item->newMetadata[CacheItem::METADATA_TAGS]);
+            $this->assertSame(['foo' => 'foo', 'bar' => 'bar', 'baz' => 'baz', 'qux' => 'qux', 'quux' => 'quux', 'quuux' => 'quuux'], $item->newMetadata[CacheItem::METADATA_TAGS]);
         }, $this, CacheItem::class))();
     }
 
diff --git a/src/Symfony/Component/Cache/Tests/Fixtures/StringableTag.php b/src/Symfony/Component/Cache/Tests/Fixtures/StringableTag.php
new file mode 100644
index 0000000000..caaf55c026
--- /dev/null
+++ b/src/Symfony/Component/Cache/Tests/Fixtures/StringableTag.php
@@ -0,0 +1,30 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Tests\Fixtures;
+
+class StringableTag
+{
+    /**
+     * @var string
+     */
+    private $tag;
+
+    public function __construct(string $tag)
+    {
+        $this->tag = $tag;
+    }
+
+    public function __toString(): string
+    {
+        return $this->tag;
+    }
+}