1 files changed, 72 insertions, 0 deletions
diff --git a/modules/libpref/test/unit_ipc/test_user_default_prefs.js b/modules/libpref/test/unit_ipc/test_user_default_prefs.js
new file mode 100644
index 0000000000..3307522513
--- /dev/null
+++ b/modules/libpref/test/unit_ipc/test_user_default_prefs.js
@@ -0,0 +1,72 @@
+const pb = Services.prefs;
+
+// This pref is chosen somewhat arbitrarily --- we just need one
+// that's guaranteed to have a default value.
+const kPrefName = "intl.accept_languages"; // of type char, which we
+// assume below
+var initialValue = null;
+
+function check_child_pref_info_eq(continuation) {
+  sendCommand(
+    'var pb = Components.classes["@mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefBranch);\n' +
+      // Returns concatenation "[value],[isUser]"
+      'pb.getCharPref("' +
+      kPrefName +
+      '")+ "," +' +
+      'pb.prefHasUserValue("' +
+      kPrefName +
+      '");',
+    function (info) {
+      let [value, isUser] = info.split(",");
+      Assert.equal(pb.getCharPref(kPrefName), value);
+      Assert.equal(pb.prefHasUserValue(kPrefName), isUser == "true");
+      continuation();
+    }
+  );
+}
+
+function run_test() {
+  // We finish in clean_up()
+  do_test_pending();
+
+  initialValue = pb.getCharPref(kPrefName);
+
+  test_user_setting();
+}
+
+function test_user_setting() {
+  // We rely on setting this before the content process starts up.
+  // When it starts up, it should recognize this as a user pref, not
+  // a default pref.
+  pb.setCharPref(kPrefName, "i-imaginarylanguage");
+  // NB: processing of the value-change notification in the child
+  // process triggered by the above set happens-before the remaining
+  // code here
+  check_child_pref_info_eq(function () {
+    Assert.equal(pb.prefHasUserValue(kPrefName), true);
+
+    test_cleared_is_default();
+  });
+}
+
+function test_cleared_is_default() {
+  pb.clearUserPref(kPrefName);
+  // NB: processing of the value-change notification in the child
+  // process triggered by the above set happens-before the remaining
+  // code here
+  check_child_pref_info_eq(function () {
+    Assert.equal(pb.prefHasUserValue(kPrefName), false);
+
+    clean_up();
+  });
+}
+
+function clean_up() {
+  pb.setCharPref(kPrefName, initialValue);
+  // NB: processing of the value-change notification in the child
+  // process triggered by the above set happens-before the remaining
+  // code here
+  check_child_pref_info_eq(function () {
+    do_test_finished();
+  });
+}