Bug 1413501 - Test for SpinningSynchronousClose unregisterConnection edge-case. r=mak

--HG--
extra : rebase_source : fd275beb962ece0fc85765abfe7d28e6b88e887a
extra : source : 16a37706634172c5f07d81a2086b800af92146de

storage/test/unit/test_connection_failsafe_close.js

@@ -0,0 +1,34 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * This file tests edge-cases related to mozStorageService::unregisterConnection
+ * in the face of failsafe closing at destruction time which results in
+ * SpinningSynchronousClose being invoked which can "resurrect" the connection
+ * and result in a second call to unregisterConnection.
+ *
+ * See https://bugzilla.mozilla.org/show_bug.cgi?id=1413501 for more context.
+ */
+
+add_task(async function test_failsafe_close_of_async_connection() {
+  // get the db
+  let db = getOpenedDatabase();
+
+  // do something async
+  let callbackInvoked = new Promise((resolve) => {
+    db.executeSimpleSQLAsync("CREATE TABLE test (id INTEGER)",
+                             { handleCompletion: resolve });
+  });
+
+  // drop our reference and force a GC so the only live reference is owned by
+  // the async statement.
+  db = gDBConn = null;
+  // (we don't need to cycle collect)
+  Components.utils.forceGC();
+
+  // now we need to wait for that callback to have completed.
+  await callbackInvoked;
+
+  Assert.ok(true, "if we shutdown cleanly and do not crash, then we succeeded");
+});

storage/test/unit/xpcshell.ini

@@ -18,6 +18,10 @@ fail-if = os == "android"
 [test_connection_asyncClose.js]
 [test_connection_executeAsync.js]
 [test_connection_executeSimpleSQLAsync.js]
+[test_connection_failsafe_close.js]
+# The failsafe close mechanism asserts when performing SpinningSynchronousClose
+# on debug builds, so we can only test on non-debug builds.
+skip-if = debug
 [test_connection_interrupt.js]
 [test_js_helpers.js]
 [test_levenshtein.js]