Move trailing slash removal to client Router, make client route "/play/" work for facebook

app/core/Router.coffee

@@ -112,7 +112,7 @@ module.exports = class CocoRouter extends Backbone.Router
 
     'multiplayer': go('MultiplayerView')
 
-    'play': go('play/CampaignView')
+    'play(/)': go('play/CampaignView') # extra slash is to get Facebook app to work
     'play/ladder/:levelID/:leagueType/:leagueID': go('ladder/LadderView')
     'play/ladder/:levelID': go('ladder/LadderView')
     'play/ladder': go('ladder/MainLadderView')
@@ -131,11 +131,15 @@ module.exports = class CocoRouter extends Backbone.Router
     #'user/:slugOrID/profile': go('user/JobProfileView')
     'user/:slugOrID/profile': go('EmployersView')  # Show the not-recruiting-now screen
 
+    '*name/': 'removeTrailingSlash'
     '*name': go('NotFoundView')
 
   routeToServer: (e) ->
     window.location.href = window.location.href
 
+  removeTrailingSlash: (e) ->
+    @navigate e, {trigger: true}
+
   routeDirectly: (path, args) ->
     path = "views/#{path}" if not _.string.startsWith(path, 'views/')
     ViewClass = @tryToLoadModule path

server_setup.coffee

@@ -128,11 +128,6 @@ setupRedirectMiddleware = (app) ->
     nameOrID = req.path.split('/')[3]
     res.redirect 301, "/user/#{nameOrID}/profile"
 
-setupTrailingSlashRemovingMiddleware = (app) ->
-  app.use (req, res, next) ->
-    # Remove trailing slashes except for in /file/.../ URLs, because those are treated as directory listings.
-    return res.redirect 301, req.url[...-1] if req.url.length > 1 and req.url.slice(-1) is '/' and not /\/file\//.test req.url
-    next()
 
 exports.setupMiddleware = (app) ->
   setupCountryRedirectMiddleware app, "china", "CN", "zh", "tokyo"
@@ -141,7 +136,6 @@ exports.setupMiddleware = (app) ->
   setupExpressMiddleware app
   setupPassportMiddleware app
   setupOneSecondDelayMiddleware app
-  setupTrailingSlashRemovingMiddleware app
   setupRedirectMiddleware app
   setupErrorMiddleware app
   setupJavascript404s app