Launching a web server inside ruby tests
Question
I'm writing a library to wrap tsung's functionality in a way that can be better used by rails applications. I want to write some integration tests that boil down to the following:
- launch a simple web server
- run tsung-recorder via the library
- launch selenium, with a firefox profile configured to use the tsung proxy, and have this fetch a page from the server launched in step 1
- examine the recorded library (it exists, it's in the correct location, etc.)
For step 1, while I could launch a vanilla rails app externally (e.g., %x{rails s}
), I'm pretty sure there's a better way to programmatically create a simple web server suitable for testing.
tl;dr - What's a way to programmatically launch a simple web server inside a test?
Solution
capybara uses an ad-hoc Rack server for its specs:
- https://github.com/jnicklas/capybara/blob/master/lib/capybara/server.rb
- https://github.com/jnicklas/capybara/blob/master/spec/server_spec.rb
Any Rack app (including Rails applications) can be served using this system, though the Rails configuration might get a bit tricky.
OTHER TIPS
You can roll your own simple server. Here's a quick example using thin and rspec (those gems, plus rack, must be installed):
# spec/support/test_server.rb
require 'rubygems'
require 'rack'
module MyApp
module Test
class Server
def call(env)
@root = File.expand_path(File.dirname(__FILE__))
path = Rack::Utils.unescape(env['PATH_INFO'])
path += 'index.html' if path == '/'
file = @root + "#{path}"
params = Rack::Utils.parse_nested_query(env['QUERY_STRING'])
if File.exists?(file)
[ 200, {"Content-Type" => "text/html"}, File.read(file) ]
else
[ 404, {'Content-Type' => 'text/plain'}, 'file not found' ]
end
end
end
end
end
Then in your spec_helper
:
# Include all files under spec/support
Dir["./spec/support/**/*.rb"].each {|f| require f}
# Start a local rack server to serve up test pages.
@server_thread = Thread.new do
Rack::Handler::Thin.run MyApp::Test::Server.new, :Port => 9292
end
sleep(1) # wait a sec for the server to be booted
This will serve any file that you store in the spec/support
directory. Including itself. For all other requests it will return a 404.
This is basically what capybara does as mentioned in the previous answer, minus a lot of sophistication.
stub_server is a real testing server that can serve pre-defined replies and is easy to spin up ... comes with ssl support too.