--- a/browser/components/extensions/test/xpcshell/test_ext_browsingData_cookies_cache.js
+++ b/browser/components/extensions/test/xpcshell/test_ext_browsingData_cookies_cache.js
@@ -23,16 +23,18 @@ const COOKIE_ORG = {
 let since, oldCookie;
 
 function addCookie(cookie) {
   Services.cookies.add(cookie.host, cookie.path, cookie.name, "test", false, false, false, Date.now() / 1000 + 10000);
   ok(Services.cookies.cookieExists(cookie), `Cookie ${cookie.name} was created.`);
 }
 
 async function setUpCookies() {
+  Services.cookies.removeAll();
+
   // Add a cookie which will end up with an older creationTime.
   oldCookie = Object.assign({}, COOKIE, {name: Date.now()});
   addCookie(oldCookie);
   await new Promise(resolve => setTimeout(resolve, 10));
   since = Date.now();
   await new Promise(resolve => setTimeout(resolve, 10));
 
   // Add a cookie which will end up with a more recent creationTime.

--- a/toolkit/components/extensions/Schemas.jsm
+++ b/toolkit/components/extensions/Schemas.jsm
@@ -811,17 +811,17 @@ class InjectionContext extends Context {
  * format.
  */
 const FORMATS = {
   hostname(string, context) {
     let valid = true;
 
     try {
       valid = new URL(`http://${string}`).host === string;
-    } catch(_) {
+    } catch (e) {
       valid = false;
     }
 
     if (!valid) {
       throw new Error(`Invalid hostname ${string}`);
     }
 
     return string;