Setting up a Rake task for Jasmine/Karma

lib/tasks/karma.rake

@@ -0,0 +1,31 @@
+namespace :karma  do
+  task :start => :environment do
+    with_tmp_config :start
+  end
+
+  task :run => :environment do
+    with_tmp_config :start, "--single-run"
+  end
+
+  private
+
+  def with_tmp_config(command, args = nil)
+    Tempfile.open('karma_unit.js', Rails.root.join('tmp') ) do |f|
+      f.write unit_js(application_spec_files)
+      f.flush
+      system "karma #{command} #{f.path} #{args}"
+    end
+  end
+
+  def application_spec_files
+    sprockets = Rails.application.assets
+    sprockets.append_path Rails.root.join("spec/javascripts")
+    files = Rails.application.assets.find_asset("application_spec.js").to_a.map {|e| e.pathname.to_s }
+  end
+
+  def unit_js(files)
+    puts files
+    unit_js = File.open('config/ng-test.conf.js', 'r').read
+    unit_js.gsub "APPLICATION_SPEC", "\"#{files.join("\",\n\"")}\""
+  end
+end