diff -r 000000000000 -r 6474c204b198 services/sync/tests/unit/test_service_persistLogin.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/services/sync/tests/unit/test_service_persistLogin.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,46 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+Cu.import("resource://services-sync/constants.js");
+Cu.import("resource://services-sync/service.js");
+Cu.import("resource://services-sync/util.js");
+Cu.import("resource://testing-common/services/sync/utils.js");
+
+function run_test() {
+  try {
+    // Ensure we have a blank slate to start.
+    ensureLegacyIdentityManager();
+    Services.logins.removeAllLogins();
+
+    setBasicCredentials("johndoe", "ilovejane", "abbbbbcccccdddddeeeeefffff");
+
+    _("Confirm initial environment is empty.");
+    let logins = Services.logins.findLogins({}, PWDMGR_HOST, null,
+                                        PWDMGR_PASSWORD_REALM);
+    do_check_eq(logins.length, 0);
+    logins = Services.logins.findLogins({}, PWDMGR_HOST, null,
+                                        PWDMGR_PASSPHRASE_REALM);
+    do_check_eq(logins.length, 0);
+
+    _("Persist logins to the login service");
+    Service.persistLogin();
+
+    _("The password has been persisted in the login service.");
+    logins = Services.logins.findLogins({}, PWDMGR_HOST, null,
+                                        PWDMGR_PASSWORD_REALM);
+    do_check_eq(logins.length, 1);
+    do_check_eq(logins[0].username, "johndoe");
+    do_check_eq(logins[0].password, "ilovejane");
+
+    _("The passphrase has been persisted in the login service.");
+    logins = Services.logins.findLogins({}, PWDMGR_HOST, null,
+                                        PWDMGR_PASSPHRASE_REALM);
+    do_check_eq(logins.length, 1);
+    do_check_eq(logins[0].username, "johndoe");
+    do_check_eq(logins[0].password, "abbbbbcccccdddddeeeeefffff");
+
+  } finally {
+    Svc.Prefs.resetBranch("");
+    Services.logins.removeAllLogins();
+  }
+}