1 files changed, 40 insertions, 0 deletions
diff --git a/services/common/tests/unit/test_utils_json.js b/services/common/tests/unit/test_utils_json.js
new file mode 100644
index 0000000000..429ac6492c
--- /dev/null
+++ b/services/common/tests/unit/test_utils_json.js
@@ -0,0 +1,40 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+Cu.import("resource://services-common/utils.js");
+Cu.import("resource://gre/modules/osfile.jsm");
+
+function run_test() {
+  initTestLogging();
+  run_next_test();
+}
+
+add_test(function test_writeJSON_readJSON() {
+  _("Round-trip some JSON through the promise-based JSON writer.");
+
+  let contents = {
+    "a": 12345.67,
+    "b": {
+      "c": "héllö",
+    },
+    "d": undefined,
+    "e": null,
+  };
+
+  function checkJSON(json) {
+    do_check_eq(contents.a, json.a);
+    do_check_eq(contents.b.c, json.b.c);
+    do_check_eq(contents.d, json.d);
+    do_check_eq(contents.e, json.e);
+    run_next_test();
+  };
+
+  function doRead() {
+    CommonUtils.readJSON(path)
+               .then(checkJSON, do_throw);
+  }
+
+  let path = OS.Path.join(OS.Constants.Path.profileDir, "bar.json");
+  CommonUtils.writeJSON(contents, path)
+             .then(doRead, do_throw);
+});