Bugfix: Cache::getValue() should return false in case of missing key

CHANGELOG.md

@@ -4,7 +4,7 @@ Yii Framework 2 redis extension Change Log
 2.0.18 under development
 ------------------------
 
-- no changes in this release.
+- Bug #247: `Cache::getValue()` now returns `false` in case of missing key (rhertogh)
 
 
 2.0.17 January 11, 2022

UPGRADE.md

@@ -12,6 +12,16 @@ if you want to upgrade from version A to version C and there is
 version B between A and C, you need to follow the instructions
 for both A and B.
 
+Upgrade from 2.0.17
+------------------
+
+* The `Cache::getValue()` method now adheres to the specifications and returns `false` in case of a missing 
+  (or expired) key. This might have impact in the following scenarios:  
+  * You specified a custom `Cache::$serializer`, depending on the serializer used `Cache::get()` might now 
+    return `false` instead of `null` in case of a missing (or expired) key.
+  * You extended the `Cache` class, are using the protected method `Cache::getValue()` directly and expect 
+    a return value of `null` in case of a missing (or expired) key.
+
 Upgrade from 2.0.13
 ------------------
 

src/Cache.php

@@ -195,7 +195,12 @@ public function exists($key)
      */
     protected function getValue($key)
     {
-        return $this->getReplica()->executeCommand('GET', [$key]);
+        $value = $this->getReplica()->executeCommand('GET', [$key]);
+        if ($value === null) {
+            return false; // Key is not in the cache or expired
+        }
+
+        return $value;
     }
 
     /**