1 files changed, 63 insertions, 0 deletions
diff --git a/modules/libpref/test/unit/test_changeType.js b/modules/libpref/test/unit/test_changeType.js
new file mode 100644
index 000000000..573d561a4
--- /dev/null
+++ b/modules/libpref/test/unit/test_changeType.js
@@ -0,0 +1,63 @@
+/* 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/. */
+
+/* Tests for changing the type of a preference (bug 985998) */
+
+const PREF_INVALID = 0;
+const PREF_BOOL    = 128;
+const PREF_INT     = 64;
+const PREF_STRING  = 32;
+
+function run_test() {
+
+  var ps = Cc["@mozilla.org/preferences-service;1"].
+            getService(Ci.nsIPrefService);
+
+  let defaultBranch = ps.getDefaultBranch("");
+  let userBranch = ps.getBranch("");
+
+  //**************************************************************************//
+  // Can't change the type of prefs that have default values
+
+  defaultBranch.setBoolPref("TypeTest.existing.bool", true);
+  defaultBranch.setIntPref("TypeTest.existing.int", 23);
+  defaultBranch.setCharPref("TypeTest.existing.char", "hey");
+
+  // The user branch reads back the expected default
+  do_check_eq(userBranch.getBoolPref("TypeTest.existing.bool"), true);
+  do_check_eq(userBranch.getIntPref("TypeTest.existing.int"), 23);
+  do_check_eq(userBranch.getCharPref("TypeTest.existing.char"), "hey");
+
+  // All the combinations of attempted type changes
+  do_check_throws(function() {
+    userBranch.setCharPref("TypeTest.existing.bool", "boo"); }, Cr.NS_ERROR_UNEXPECTED);
+  do_check_throws(function() {
+    userBranch.setIntPref("TypeTest.existing.bool", 5); }, Cr.NS_ERROR_UNEXPECTED);
+  do_check_throws(function() {
+    userBranch.setCharPref("TypeTest.existing.int", "boo"); }, Cr.NS_ERROR_UNEXPECTED);
+  do_check_throws(function() {
+    userBranch.setBoolPref("TypeTest.existing.int", true); }, Cr.NS_ERROR_UNEXPECTED);
+  do_check_throws(function() {
+    userBranch.setBoolPref("TypeTest.existing.char", true); }, Cr.NS_ERROR_UNEXPECTED);
+  do_check_throws(function() {
+    userBranch.setIntPref("TypeTest.existing.char", 6); }, Cr.NS_ERROR_UNEXPECTED);
+
+
+  //**************************************************************************//
+  // Prefs that don't have default values can mutate
+  let pref = "TypeTest.user";
+  userBranch.setBoolPref(pref, true);
+  userBranch.setCharPref(pref, "yay");
+  do_check_eq(userBranch.getCharPref(pref), "yay");
+  userBranch.setIntPref(pref, 7);
+  do_check_eq(userBranch.getIntPref(pref), 7);
+  userBranch.setBoolPref(pref, false);
+  do_check_eq(userBranch.getBoolPref(pref), false);
+  userBranch.setIntPref(pref, 8);
+  do_check_eq(userBranch.getIntPref(pref), 8);
+  userBranch.setCharPref(pref, "whee");
+  do_check_eq(userBranch.getCharPref(pref), "whee");
+  userBranch.setBoolPref(pref, true);
+  do_check_eq(userBranch.getBoolPref(pref), true);
+}