Add Rake tasks for Webpack compilation

Hook Webpack build into standard Sprockets precompilation.

Signed-off-by: Alex Coles <alex@alexbcoles.com>

lib/tasks/assets.rake

@@ -0,0 +1,53 @@
+#-- encoding: UTF-8
+#-- copyright
+# OpenProject is a project management system.
+# Copyright (C) 2012-2014 the OpenProject Foundation (OPF)
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See doc/COPYRIGHT.rdoc for more details.
+#++
+
+# Based on a Snippet by Tom Dooner. See:
+# http://www.tomdooner.com/2014/05/26/webpack.html
+
+# The webpack task must run before assets:environment task.
+# Otherwise Sprockets cannot find the files that webpack produces.
+Rake::Task['assets:precompile']
+  .clear_prerequisites
+  .enhance(['assets:compile_environment'])
+
+namespace :assets do
+  # In this task, set prerequisites for the assets:precompile task
+  task :compile_environment => :webpack do
+    Rake::Task['assets:environment'].invoke
+  end
+
+  desc 'Compile assets with webpack'
+  task :webpack do
+    sh '$(npm bin)/webpack --config webpack.config.js'
+  end
+
+  task :clobber do
+    rm_rf FileList["#{Rails.root}/app/assets/javascripts/*.bundle.js*"]
+  end
+end