Clear cache between ThemeResourceLoader tests

src/View/ThemeResourceLoader.php

@@ -350,4 +350,12 @@ class ThemeResourceLoader
         }
         return $paths;
     }
+
+    /**
+     * Clear any internally cached data from memory
+     */
+    public static function flushCache()
+    {
+        static::$cacheData = [];
+    }
 }

tests/php/Core/Manifest/ThemeResourceLoaderTest.php

@@ -54,6 +54,9 @@ class ThemeResourceLoaderTest extends SapphireTest
         // New Loader for that root
         $this->loader = new ThemeResourceLoader($this->base);
         $this->loader->addSet('$default', $this->manifest);
+
+        // Flush any cached values
+        ThemeResourceLoader::flushCache();
     }
 
     protected function tearDown()