[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)

3 files changed, 11 insertions, 15 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
     },
 
diff --git a/addons/mail/static/src/js/models/threads/channel.js b/addons/mail/static/src/js/models/threads/channel.js
index 8f0f664b6b0..51ebe34a651 100644
--- a/addons/mail/static/src/js/models/threads/channel.js
+++ b/addons/mail/static/src/js/models/threads/channel.js
@@ -51,7 +51,7 @@ var Channel = SearchableThread.extend(ThreadTypingMixin, {
         this._autoswitch = 'autoswitch' in options ? options.autoswitch : true;
         this._commands = undefined;
         this._creatorUID = data.create_uid;
-        this._detached = data.is_minimized;
+        this._detached = data.is_minimized || false;
         this._directPartnerID = undefined;
         this._folded = data.state === 'folded';
         // if set: hide 'Leave channel' button
@@ -66,7 +66,6 @@ var Channel = SearchableThread.extend(ThreadTypingMixin, {
         // number of messages in this channel that are in inbox.
         this._needactionCounter = data.message_needaction_counter || 0;
         this._serverType = data.channel_type;
-        this._status = undefined;
         this._throttleFetchSeen = _.throttle(this._fetchSeen.bind(this), 3000);
         // unique identifier for this channel, which is required for some rpc
         this._uuid = data.uuid;
diff --git a/addons/mail/static/src/js/models/threads/mailbox.js b/addons/mail/static/src/js/models/threads/mailbox.js
index f3e0754ee20..f3b541d07a7 100644
--- a/addons/mail/static/src/js/models/threads/mailbox.js
+++ b/addons/mail/static/src/js/models/threads/mailbox.js
@@ -46,11 +46,8 @@ var Mailbox = SearchableThread.extend({
         this._mailboxCounter = Math.max(this._mailboxCounter - num, 0);
     },
     /**
-     * Get the local messages of the mailbox (by local messages, we mean
-     * messages that have already been fetched from the server).
-     *
-     * It is possible to filter on local messages that are specific to a
-     * document with the `options` parameter.
+     * Override so that there are options to filter messages based on document
+     * model and ID.
      *
      * @param {Object} [options]
      * @param {string} [options.documentModel] model of the document that the
@@ -58,15 +55,15 @@ var Mailbox = SearchableThread.extend({
      * @param {integer} [options.documentID] ID of the document that the local
      *   messages of inbox must be linked to.
      */
-    getLocalMessages: function (options) {
-        var localMessages = this._cache['[]'].messages;
+    getMessages: function (options) {
+        var messages = this._super.apply(this, arguments);
         if (!options) {
-            return localMessages;
+            return messages;
         }
         if (options.documentModel && options.documentID) {
-            return _.filter(localMessages, function (localMessage) {
-                return localMessage.getDocumentModel() === options.documentModel &&
-                        localMessage.getDocumentID() === options.documentID;
+            return _.filter(messages, function (message) {
+                return message.getDocumentModel() === options.documentModel &&
+                        message.getDocumentID() === options.documentID;
             });
         }
     },