1 files changed, 47 insertions, 0 deletions
diff --git a/services/sync/tests/unit/test_service_sync_locked.js b/services/sync/tests/unit/test_service_sync_locked.js
new file mode 100644
index 0000000000..5a872e2708
--- /dev/null
+++ b/services/sync/tests/unit/test_service_sync_locked.js
@@ -0,0 +1,47 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const { Service } = ChromeUtils.importESModule(
+  "resource://services-sync/service.sys.mjs"
+);
+
+add_task(async function run_test() {
+  validate_all_future_pings();
+  let debug = [];
+  let info = [];
+
+  function augmentLogger(old) {
+    let d = old.debug;
+    let i = old.info;
+    // For the purposes of this test we don't need to do full formatting
+    // of the 2nd param, as the ones we care about are always strings.
+    old.debug = function (m, p) {
+      debug.push(p ? m + ": " + (p.message || p) : m);
+      d.call(old, m, p);
+    };
+    old.info = function (m, p) {
+      info.push(p ? m + ": " + (p.message || p) : m);
+      i.call(old, m, p);
+    };
+    return old;
+  }
+
+  Log.repository.rootLogger.addAppender(new Log.DumpAppender());
+
+  augmentLogger(Service._log);
+
+  // Avoid daily ping
+  Svc.PrefBranch.setIntPref("lastPing", Math.floor(Date.now() / 1000));
+
+  _("Check that sync will log appropriately if already in 'progress'.");
+  Service._locked = true;
+  await Service.sync();
+  Service._locked = false;
+
+  Assert.ok(
+    debug[debug.length - 2].startsWith(
+      'Exception calling WrappedLock: Could not acquire lock. Label: "service.js: login".'
+    )
+  );
+  Assert.equal(info[info.length - 1], "Cannot start sync: already syncing?");
+});