DEV: Add unambiguous routes for tags

The trouble with having:

/tags/:tag_id/...

and:

/tags/intersection/*tag_ids

for example, is: what happens if you want a tag called intersection?

Under this new scheme. Routes referring to a single tag are unambiguous
because they are prefixed with:

/tag/:tag_id

Routes referring to the collection of tags still start with:

/tags/

This commit just adds the new routes. It doesn't remove the old ones or
cause the new ones to be used.

app/assets/javascripts/discourse/pre-initializers/dynamic-route-builders.js.es6

@@ -103,10 +103,15 @@ export default {
     });
     app["TagsShowParentCategoryRoute"] = TagsShowRoute.extend();
 
+    app["TagShowRoute"] = TagsShowRoute;
+
     site.get("filters").forEach(function(filter) {
       app["TagsShow" + filter.capitalize() + "Route"] = TagsShowRoute.extend({
         navMode: filter
       });
+      app["TagShow" + filter.capitalize() + "Route"] = TagsShowRoute.extend({
+        navMode: filter
+      });
       app[
         "TagsShowCategory" + filter.capitalize() + "Route"
       ] = TagsShowRoute.extend({ navMode: filter });

app/assets/javascripts/discourse/routes/app-route-map.js.es6

@@ -209,8 +209,17 @@ export default function() {
 
   this.route("full-page-search", { path: "/search" });
 
-  this.route("tags", { resetNamespace: true }, function() {
+  this.route("tag", { resetNamespace: true }, function() {
     this.route("show", { path: "/:tag_id" });
+
+    Site.currentProp("filters").forEach(filter => {
+      this.route("show" + filter.capitalize(), {
+        path: "/:tag_id/l/" + filter
+      });
+    });
+  });
+
+  this.route("tags", { resetNamespace: true }, function() {
     this.route("showCategory", {
       path: "/c/*category_slug_path_with_id/:tag_id"
     });
@@ -219,9 +228,6 @@ export default function() {
     });
 
     Site.currentProp("filters").forEach(filter => {
-      this.route("show" + filter.capitalize(), {
-        path: "/:tag_id/l/" + filter
-      });
       this.route("showCategory" + filter.capitalize(), {
         path: "/c/*category_slug_path_with_id/:tag_id/l/" + filter
       });
@@ -232,6 +238,14 @@ export default function() {
     this.route("intersection", {
       path: "intersection/:tag_id/*additional_tags"
     });
+
+    // legacy routes
+    this.route("show", { path: "/:tag_id" });
+    Site.currentProp("filters").forEach(filter => {
+      this.route("show" + filter.capitalize(), {
+        path: "/:tag_id/l/" + filter
+      });
+    });
   });
 
   this.route(

config/routes.rb

@@ -840,6 +840,27 @@ Discourse::Application.routes.draw do
   get "apple-app-site-association" => "metadata#app_association_ios", format: false
   get "opensearch" => "metadata#opensearch", constraints: { format: :xml }
 
+  scope '/tag/:tag_id' do
+    constraints format: :json do
+      get '/' => 'tags#show'
+      get '/info' => 'tags#info'
+      get '/notifications' => 'tags#notifications'
+      put '/notifications' => 'tags#update_notifications'
+      put '/' => 'tags#update'
+      delete '/' => 'tags#destroy'
+      post '/synonyms' => 'tags#create_synonyms'
+      delete '/synonyms/:synonym_id' => 'tags#destroy_synonym'
+
+      Discourse.filters.each do |filter|
+        get "/l/#{filter}" => "tags#show_#{filter}"
+      end
+    end
+
+    constraints format: :rss do
+      get '/' => 'tags#tag_feed'
+    end
+  end
+
   scope "/tags" do
     get '/' => 'tags#index'
     get '/filter/list' => 'tags#index'
@@ -849,6 +870,7 @@ Discourse::Application.routes.draw do
     post '/upload' => 'tags#upload'
     get '/unused' => 'tags#list_unused'
     delete '/unused' => 'tags#destroy_unused'
+
     constraints(tag_id: /[^\/]+?/, format: /json|rss/) do
       scope path: '/c/*category_slug_path_with_id' do
         Discourse.filters.each do |filter|
@@ -864,9 +886,13 @@ Discourse::Application.routes.draw do
         get '/:tag_id' => 'tags#show', as: 'tag_category_show'
       end
 
+      get '/intersection/:tag_id/*additional_tag_ids' => 'tags#show', as: 'tag_intersection'
+    end
+
+    # legacy routes
+    constraints(tag_id: /[^\/]+?/, format: /json|rss/) do
       get '/:tag_id.rss' => 'tags#tag_feed'
       get '/:tag_id' => 'tags#show', as: 'tag_show'
-      get '/intersection/:tag_id/*additional_tag_ids' => 'tags#show', as: 'tag_intersection'
       get '/:tag_id/info' => 'tags#info'
       get '/:tag_id/notifications' => 'tags#notifications'
       put '/:tag_id/notifications' => 'tags#update_notifications'