Change default Capybara browser window size

A proper way to do it for all js tests is to add following inside spec_helper.rb RSpec.configure block

config.before(:each, js: true) do
  Capybara.page.driver.browser.manage.window.maximize
end

to maximize the window. Change to resize_to(x,y) to set any window size.

EDIT: If you happen to be using Poltergeist the correct way to do it is

config.before(:each, js: true) do
  Capybara.page.driver.browser.resize(x,y)
end