added test case

packages/cache/src/cache.ts

@@ -50,11 +50,7 @@ function checkKey(key: string): void {
  */
 
 export function isFeatureAvailable(): boolean {
-  if (process.env['ACTIONS_CACHE_URL']) {
-    return true
-  }
-
-  return false
+  return utils.isFeatureAvailable();
 }
 
 /**

packages/cache/src/internal/cacheUtils.ts

@@ -123,3 +123,11 @@ export function assertDefined<T>(name: string, value?: T): T {
 
   return value
 }
+
+export function isFeatureAvailable(): boolean {
+  if (process.env["ACTIONS_CACHE_URL"]) {
+    return true
+  }
+  
+  return false
+}