use build? helper

lib/middleman/features/cache_buster.rb

@@ -16,7 +16,7 @@ module Middleman::Features::CacheBuster
 
           if File.readable?(real_path_static)
             http_path << "?" + File.mtime(real_path_static).strftime("%s") 
-          elsif app.environment == :build
+          elsif app.build?
             real_path_dynamic = File.join(app.root, app.build_dir, prefix, path)
             http_path << "?" + File.mtime(real_path_dynamic).strftime("%s") if File.readable?(real_path_dynamic)
           end

lib/middleman/features/live_reload.rb

@@ -1,7 +1,7 @@
 module Middleman::Features::LiveReload
   class << self
     def registered(app)
-      return unless Middleman::Server.environment == :development
+      return unless Middleman::Server.development?
 
       begin
         require 'livereload'

lib/middleman/features/minify_javascript.rb

@@ -2,7 +2,7 @@ module Middleman::Features::MinifyJavascript
   class << self
     def registered(app)
       # Only do minification on build or prod mode
-      return unless [:build, :production].include? app.environment
+      return unless app.build? || app.production?
 
       require "middleman/features/minify_javascript/rack"
       app.use Middleman::Rack::MinifyJavascript

lib/middleman/renderers/sass.rb

@@ -14,7 +14,7 @@ module Middleman::Renderers::Sass
     def sass_options
       return super if basename.nil?
 
-      location_of_sass_file = if Middleman::Server.environment == :build
+      location_of_sass_file = if Middleman::Server.build?
         File.join(Middleman::Server.root, Middleman::Server.build_dir)
       else
         Middleman::Server.views

lib/middleman/server.rb

@@ -14,6 +14,7 @@ module Middleman
         super(option, value, &nil)
       end
       
+      # Convenience method to check if we're in build mode
       def build?; environment == :build; end
     end