1 files changed, 34 insertions, 0 deletions
diff --git a/browser/components/tests/unit/test_browserGlue_migration_no_errors.js b/browser/components/tests/unit/test_browserGlue_migration_no_errors.js
new file mode 100644
index 0000000000..aed88c95fe
--- /dev/null
+++ b/browser/components/tests/unit/test_browserGlue_migration_no_errors.js
@@ -0,0 +1,34 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Since various migrations in BrowserGlue are sometimes trivial, e.g. just
+ * clearing a pref, it does not feel necessary to write tests for each of those.
+ *
+ * However, ensuring we have at least some coverage to check for errors, e.g.
+ * typos, is a good idea, hence this test.
+ *
+ * If your migration is more complex that clearing a couple of prefs, you
+ * should consider adding your own BrowserGlue migration test.
+ */
+const TOPIC_BROWSERGLUE_TEST = "browser-glue-test";
+const TOPICDATA_BROWSERGLUE_TEST = "force-ui-migration";
+
+const gBrowserGlue = Cc["@mozilla.org/browser/browserglue;1"].getService(
+  Ci.nsIObserver
+);
+
+// Set the migration value to 1, to ensure that the migration code is called,
+// and so that this doesn't need updating every time we obsolete old tests.
+Services.prefs.setIntPref("browser.migration.version", 1);
+
+add_task(async function test_no_errors() {
+  // Simulate a migration.
+  gBrowserGlue.observe(
+    null,
+    TOPIC_BROWSERGLUE_TEST,
+    TOPICDATA_BROWSERGLUE_TEST
+  );
+
+  Assert.ok(true, "should have run the migration with no errors");
+});