[REF] mail: clean some JS code

1. Removed `getLocalMessages` method in mailbox, and replaced
   with an override on `getMessages`.

   (This method was used before the distinction was made
   between `getMessages` and `fetchMessages`)

2. Removed unused method `_warnUpdatedUnreadCounter` in
   abstract thread window.

   (Leftover from an early POC)

3. Set the default value `''` for the status of a thread.

   (The method `getStatus` should always return a string)

4. Enforce default value `false` for detached status of channel.

   (The method `isDetached` should always return a boolean)

5. Improve readability of some tests.

   (removed useless variables and/or redundant code)

1 files changed, 2 insertions, 2 deletions

diff --git a/addons/mail/static/src/js/models/threads/abstract_thread.js b/addons/mail/static/src/js/models/threads/abstract_thread.js
index 322541af016..b0a7f1d0b2e 100644
--- a/addons/mail/static/src/js/models/threads/abstract_thread.js
+++ b/addons/mail/static/src/js/models/threads/abstract_thread.js
@@ -16,7 +16,7 @@ var AbstractThread = Class.extend(Mixins.EventDispatcherMixin, {
      * @param {Object} params.data
      * @param {integer|string} params.data.id the ID of this thread
      * @param {string} params.data.name the name of this thread
-     * @param {string} params.data.status the status of this thread
+     * @param {string} [params.data.status=''] the status of this thread
      * @param {Object} params.parent Object with the event-dispatcher mixin
      *   (@see {web.mixins.EventDispatcherMixin})
      */
@@ -27,7 +27,7 @@ var AbstractThread = Class.extend(Mixins.EventDispatcherMixin, {
         this._folded = false; // threads are unfolded by default
         this._id = params.data.id;
         this._name = params.data.name;
-        this._status = params.data.status;
+        this._status = params.data.status || '';
         this._unreadCounter = 0; // amount of messages not yet been read
     },