Remove a bunch of old deprecated code

app/assets/javascripts/discourse/helpers/plugin-outlet.js.es6

@@ -81,14 +81,7 @@ function findOutlets(collection, callback) {
         }
       }
 
-      const dashedName = outletName.replace(/_/g, '-');
-      if (dashedName !== outletName) {
-        Ember.warn("DEPRECATION: You need to use dashes in outlet names, not underscores");
-        callback(dashedName, res, uniqueName);
-      } else {
-        callback(outletName, res, uniqueName);
-      }
-
+      callback(outletName, res, uniqueName);
     }
   });
 }

app/assets/javascripts/discourse/initializers/lab-deprecation.js.es6

@@ -1,19 +0,0 @@
-import loadScript from 'discourse/lib/load-script';
-
-export default {
-  name: 'lab-deprecation',
-
-  initialize() {
-    if (window.$LAB) { return; }
-
-    window.$LAB = {
-      script(path) {
-        Ember.warn('$LAB is not included with Discouse anymore. Use `loadScript` instead.');
-
-        const promise = loadScript(path);
-        promise.wait = promise.then;
-        return promise;
-      }
-    };
-  }
-};

app/assets/javascripts/discourse/initializers/message-bus.js.es6

@@ -11,14 +11,6 @@ export default {
       user = container.lookup('current-user:main'),
       siteSettings = container.lookup('site-settings:main');
 
-    const deprecatedBus = {};
-    deprecatedBus.prototype = messageBus;
-    deprecatedBus.subscribe = function() {
-      Ember.warn("Discourse.MessageBus is deprecated. Use `this.messageBus` instead");
-      messageBus.subscribe.apply(messageBus, Array.prototype.slice(arguments));
-    };
-    Discourse.MessageBus = deprecatedBus;
-
     messageBus.alwaysLongPoll = Discourse.Environment === "development";
     messageBus.start();
 

app/assets/javascripts/discourse/initializers/sharing-sources.js.es6

@@ -4,14 +4,6 @@ export default {
   name: 'sharing-sources',
 
   initialize: function() {
-    // Backwards compatibility
-    Discourse.ShareLink = {};
-    Discourse.ShareLink.addTarget = function(id, source) {
-      Ember.warn('Discourse.ShareLink.addTarget is deprecated. Import `Sharing` and call `addSource` instead.');
-      source.id = id;
-      Sharing.addSource(source);
-    };
-
     Sharing.addSource({
       id: 'twitter',
       faIcon: 'fa-twitter-square',

app/assets/javascripts/discourse/lib/show-modal.js.es6

@@ -1,11 +1,5 @@
 export default function(name, opts) {
   opts = opts || {};
-
-  if (opts.__type) {
-    Ember.warn("showModal now takes `opts` as a second param instead of a model");
-    opts = {model: opts};
-  }
-
   const container = Discourse.__container__;
 
   // We use the container here because modals are like singletons

app/assets/javascripts/discourse/mixins/ajax.js

@@ -35,11 +35,8 @@ Discourse.Ajax = Em.Mixin.create({
       args = arguments[1];
     }
 
-    if (args.success) {
-      throw "Discourse.ajax should use promises, received 'success' callback";
-    }
-    if (args.error) {
-      throw "DEPRECATION: Discourse.ajax should use promises, received 'error' callback";
+    if (args.success || args.error) {
+      throw "Discourse.ajax should use promises";
     }
 
     var performAjax = function(resolve, reject) {

app/assets/javascripts/discourse/models/topic-list.js.es6

@@ -135,11 +135,6 @@ TopicList.reopenClass({
     return store.findFiltered('topicList', {filter, params});
   },
 
-  list(filter) {
-    Ember.warn('`Discourse.TopicList.list` is deprecated. Use the store instead');
-    return this.find(filter);
-  },
-
   // hide the category when it has no children
   hideUniformCategory(list, category) {
     list.set('hideCategory', category && !category.get("has_children"));