add instructions for autoprefixer and NodeJS (issue #54)

did committed Feb 16, 2016

commit 818f7253f687c9ab996e8921a9e082aab76c9aca

locomotive/steam/initializers/sprockets.rb b/lib/locomotive/steam/initializers/sprockets.rb +7 -1

@@	@@ -53,7 +53,13 @@ module Locomotive::Steam
	params = (::YAML.load_file(file) \|\| {}).symbolize_keys
	AutoprefixerRails.install(self, params)

-	Locomotive::Common::Logger.info "Autoprefixer detected and installed".light_white + "\n\n"
+	Locomotive::Common::Logger.info "[Autoprefixer] detected and installed".light_white
+
+	if ENV['EXECJS_RUNTIME'].blank?
+	Locomotive::Common::Logger.warn "[Autoprefixer]".light_white + " [Warning] if you notice bad performance, install NodeJS and run \"export EXECJS_RUNTIME=Node\" in your shell"
+	end
+
+	Locomotive::Common::Logger.info "\n"
	end
	end

spec/unit/initializers/sprockets_spec.rb +11 -0

@@	@@ -24,6 +24,8 @@ describe Locomotive::Steam::SprocketsEnvironment do

	describe '#install_autoprefixer' do

+	let(:options) { { minify: false } }
+
	subject { env }

	context "config/autoprefixer.yml doesn't exist" do
@@	@@ -43,6 +45,15 @@ describe Locomotive::Steam::SprocketsEnvironment do

	it { expect(AutoprefixerRails).to receive(:install).and_return(true); subject }

+	it 'warns developers if they notice bad performance when using autoprefixer' do
+	curent_execjs_runtime = ENV['EXECJS_RUNTIME']
+	ENV['EXECJS_RUNTIME'] = 'NodeJS'
+	expect(Locomotive::Common::Logger).not_to receive(:warn)
+	expect(AutoprefixerRails).to receive(:install).and_return(true)
+	subject
+	ENV['EXECJS_RUNTIME'] = curent_execjs_runtime
+	end
+
	end

	end