Fix DeviceDetectorCache cache eviction flakiness

Author: tzi

CachedEntry.php

@@ -60,6 +60,7 @@ public static function getCached(string $userAgent): ?array
         if ($exists) {
             $values = @include($path);
             if (!empty($values) && is_array($values) && isset($values['os'])) {
+                self::refreshAccessTime($path);
                 return $values;
             }
         }
@@ -165,6 +166,16 @@ private static function getCacheFilesInCacheDir(): array
         });
     }
 
+    private static function refreshAccessTime(string $path): void
+    {
+        $modifiedTime = @filemtime($path);
+        if ($modifiedTime === false) {
+            return;
+        }
+
+        @touch($path, $modifiedTime, time());
+    }
+
     public static function deleteLeastAccessedFiles(int $numFilesToDelete): void
     {
         if ($numFilesToDelete < 1) {

tests/Integration/CachedEntryTest.php

@@ -190,6 +190,18 @@ public function test_writeToCache_GetCached()
         );
     }
 
+    public function testGetCached_refreshesAccessTime()
+    {
+        $filePath = CachedEntry::writeToCache('foo', []);
+        $accessTimeBefore = fileatime($filePath);
+
+        sleep(1);
+        CachedEntry::getCached('foo', []);
+        clearstatcache(true, $filePath);
+
+        $this->assertGreaterThan($accessTimeBefore, fileatime($filePath));
+    }
+
     public function test_getCachePath()
     {
         $path1 = CachedEntry::getCachePath('foo');

tests/Integration/WarmDeviceDetectorCacheTest.php

@@ -106,9 +106,8 @@ public function testDoesNotClearExistingFilesFromCacheByDefault()
 
     public function testDoesClearExistingFilesFromCacheByDefaultWhenTooManyEntriesExist()
     {
-        // was last accessed
-        $userAgentKept     = 'Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko';
-        $userAgentDeleted  = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36';
+        $userAgentKept = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36';
+        $userAgentDeleted = 'Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko';
         $cacheFilePathKept = CachedEntry::getCachePath($userAgentKept, true);
         $cacheFilePathDeleted = CachedEntry::getCachePath($userAgentDeleted, true);
 
@@ -128,7 +127,7 @@ public function testDoesClearExistingFilesFromCacheByDefaultWhenTooManyEntriesEx
 
         $this->setCountProcessNumEntries(1);
 
-        // now we run again and it should delete 2 of the entries
+        // now we run again and it should refresh the most frequent entry and delete the other 2
         $this->applicationTester->run([
             'command' => WarmDeviceDetectorCache::COMMAND_NAME,
         ]);