Keys with no hierarchy works

Author: Nyholm

composer.json

@@ -29,6 +29,7 @@
     {
         "php":                  "^5.5|^7.0",
         "psr/cache":            "1.0.0",
+        "cache/adapter-common": "^0.1",
         "cache/taggable-cache": "^0.2"
     },
     "require-dev":

src/HierarchicalCachePool.php

@@ -11,10 +11,10 @@
 
 namespace Cache\Hierarchy;
 
+use Cache\Adapter\Common\Exception\InvalidArgumentException;
 use Cache\Taggable\TaggablePoolInterface;
 use Psr\Cache\CacheItemInterface;
 use Psr\Cache\CacheItemPoolInterface;
-use Psr\Cache\InvalidArgumentException;
 
 /**
  * @author Tobias Nyholm <[email protected]>
@@ -45,6 +45,7 @@ public function getItem($key, array $tags = [])
         if (!$this->isHierarchyKey($key)) {
             return $this->cache->getItem($key, $tags);
         }
+
         // TODO: Implement getItem() method.
     }
 
@@ -53,10 +54,12 @@ public function getItem($key, array $tags = [])
      */
     public function getItems(array $keys = [], array $tags = [])
     {
-        if (!$this->isHierarchyKey($keys)) {
-            return $this->cache->getItems($keys, $tags);
+        $items = [];
+        foreach ($keys as $key) {
+            $items[$key] = $this->getItem($key, $tags);
         }
-        // TODO: Implement getItems() method.
+
+        return $items;
     }
 
     /**
@@ -94,34 +97,36 @@ public function deleteItem($key, array $tags = [])
      */
     public function deleteItems(array $keys, array $tags = [])
     {
-        if (!$this->isHierarchyKey($keys)) {
-            return $this->cache->deleteItems($keys, $tags);
+        $result = true;
+        foreach ($keys as $key) {
+            $result = $result && $this->deleteItem($key, $tags);
         }
-        // TODO: Implement deleteItems() method.
+
+        return $result;
     }
 
     /**
      * {@inheritdoc}
      */
     public function save(CacheItemInterface $item)
     {
-        $this->cache->save($item);
+        return $this->cache->save($item);
     }
 
     /**
      * {@inheritdoc}
      */
     public function saveDeferred(CacheItemInterface $item)
     {
-        $this->cache->saveDeferred($item);
+        return $this->cache->saveDeferred($item);
     }
 
     /**
      * {@inheritdoc}
      */
     public function commit()
     {
-        $this->cache->commit();
+        return $this->cache->commit();
     }
 
     /**
@@ -132,6 +137,10 @@ public function commit()
      */
     private function isHierarchyKey($key)
     {
+        if (!is_string($key)) {
+            throw new InvalidArgumentException(sprintf('Key must be string.'));
+        }
+
         return substr($key, 0, 1) === self::SEPARATOR;
     }
 }