Fix FileSystemCacheEngine when there is no TTS (never set cache)

Author: byjg

.travis.yml

@@ -10,6 +10,7 @@ addons:
     - redis-container
 
 php:
+  - "7.2"
   - "7.1"
   - "7.0"
   - "5.6"

composer.json

@@ -18,8 +18,12 @@
     "psr/log": "1.0.2",
     "psr/simple-cache": "1.0.*"
   },
+  "require-dev": {
+    "phpunit/phpunit": "5.7.*|6.5.*"
+  },
   "suggest": {
-    "ext-memcached": "*"
+    "ext-memcached": "*",
+    "ext-redis": "*"
   },
   "license": "MIT"
 }

src/Psr16/FileSystemCacheEngine.php

@@ -27,6 +27,7 @@ public function __construct($prefix = 'cache', $logger = null)
      * @param string $key The object KEY
      * @param mixed $default IGNORED IN MEMCACHED.
      * @return mixed Description
+     * @throws \Psr\SimpleCache\InvalidArgumentException
      */
     public function get($key, $default = null)
     {
@@ -84,6 +85,8 @@ public function set($key, $value, $ttl = null)
         try {
             if (file_exists($fileKey)) {
                 unlink($fileKey);
+            }
+            if (file_exists("$fileKey.ttl")) {
                 unlink("$fileKey.ttl");
             }