Bug 1959486 - Use NimbusTestUtils.assert.storeIsEmpty and NimbusTestUtils.removeStore everywhere r=nimbus-reviewers,settings-reviewers,relud

Differential Revision: https://phabricator.services.mozilla.com/D248563

browser/components/preferences/tests/head.js

@@ -1,6 +1,9 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
+const { NimbusTestUtils } = ChromeUtils.import(
+  "resource://testing-common/NimbusTestUtils.sys.mjs"
+);
 const { PermissionTestUtils } = ChromeUtils.importESModule(
   "resource://testing-common/PermissionTestUtils.sys.mjs"
 );
@@ -15,9 +18,10 @@ ChromeUtils.defineLazyGetter(this, "QuickSuggestTestUtils", () => {
 
 ChromeUtils.defineESModuleGetters(this, {
   ExperimentAPI: "resource://nimbus/ExperimentAPI.sys.mjs",
-  NimbusTestUtils: "resource://testing-common/NimbusTestUtils.sys.mjs",
 });
 
+NimbusTestUtils.init(this);
+
 const kDefaultWait = 2000;
 
 function is_element_visible(aElement, aMsg) {
@@ -511,15 +515,7 @@ async function setupLabsTest(recipes) {
   await ExperimentAPI._rsLoader.updateRecipes("test");
 
   return async function cleanup() {
-    const store = ExperimentAPI.manager.store;
-
-    store._store._saver.disarm();
-    if (store._store._saver.isRunning) {
-      await store._store._saver._runningPromise;
-    }
-
-    await IOUtils.remove(store._store.path);
-
+    await NimbusTestUtils.removeStore(ExperimentAPI.manager.store);
     await SpecialPowers.popPrefEnv();
   };
 }