Use Capybara to drive a generated Rails app through integration tests.

.gitignore

@@ -4,3 +4,4 @@ tmp
 test/s3.yml
 public
 paperclip*.gem
+capybara*.html

features/rails.feature

+Feature: Running paperclip in a Rails app
+
+  Scenario: Basic utilization
+    Given I generate a rails application
+    And I have a "users" resource with "name:string"
+    And I run "script/generate paperclip user avatar"
+    And I save the following as "app/models/user.rb"
+    """
+    class User < ActiveRecord::Base
+      has_attached_file :avatar
+    end
+    """
+    And I save the following as "app/views/users/new.html.erb"
+    """
+    <% form_for @user, :html => { :multipart => true } do |f| %>
+      <%= f.text_field :name %>
+      <%= f.file_field :avatar %>
+      <%= submit_tag "Submit" %>
+    <% end %>
+    """
+    And I save the following as "app/views/users/show.html.erb"
+    """
+    <p>Name: <%= @user.name %></p>
+    <p>Avatar: <%= image_tag @user.avatar.url %></p>
+    """
+    And this plugin is available
+    And the rails application is prepped and running
+    When I visit /users/new
+    And I fill in "user_name" with "something"
+    And I attach the file "test/fixtures/5k.png" to "user_avatar"
+    And I press "Submit"
+    Then I should see "Name: something"
+    And I save and open the page

features/step_definitions/rails_steps.rb

+Given %r{I generate a rails application} do
+  FileUtils.rm_rf TEMP_ROOT
+  FileUtils.mkdir_p TEMP_ROOT
+  Dir.chdir(TEMP_ROOT) do
+    `rails _2.3.8_ #{APP_NAME}`
+  end
+  ENV['RAILS_ENV'] = 'test'
+end
+
+When %r{I save the following as "([^"]*)"} do |path, string|
+  FileUtils.mkdir_p(File.join(CUC_RAILS_ROOT, File.dirname(path)))
+  File.open(File.join(CUC_RAILS_ROOT, path), 'w') { |file| file.write(string) }
+end
+
+When %r{the rails application is prepped and running$} do
+  When "the rails application is prepped"
+  When "the rails application is running"
+end
+
+When %r{the rails application is prepped$} do
+  When %{I run "rake db:create db:migrate"}
+end
+
+When %r{the rails application is running} do
+  Dir.chdir(CUC_RAILS_ROOT) do
+    require "config/environment"
+    Capybara.app = ActionController::Dispatcher.new
+  end
+end
+
+When %r{this plugin is available} do
+  $LOAD_PATH << "#{PROJECT_ROOT}/lib"
+  require 'paperclip'
+  When %{I save the following as "vendor/plugins/paperclip/rails/init.rb"},
+       IO.read("#{PROJECT_ROOT}/rails/init.rb") 
+end
+
+When %r{I run "([^"]*)"} do |command|
+  Dir.chdir(CUC_RAILS_ROOT) do
+    `#{command}`
+  end
+end
+
+When %r{I have a "([^"]*)" resource with "([^"]*)"} do |resource, fields|
+  When %{I run "script/generate scaffold #{resource} #{fields}"}
+end

features/step_definitions/web_steps.rb

+# IMPORTANT: This file is generated by cucumber-rails - edit at your own peril.
+# It is recommended to regenerate this file in the future when you upgrade to a 
+# newer version of cucumber-rails. Consider adding your own code to a new file 
+# instead of editing this one. Cucumber will automatically load all features/**/*.rb
+# files.
+
+
+require 'uri'
+require 'cgi'
+require File.expand_path(File.join(File.dirname(__FILE__), "..", "support", "paths"))
+
+module WithinHelpers
+  def with_scope(locator)
+    locator ? within(locator) { yield } : yield
+  end
+end
+World(WithinHelpers)
+
+Given /^(?:|I )am on (.+)$/ do |page_name|
+  visit path_to(page_name)
+end
+
+When /^(?:|I )go to (.+)$/ do |page_name|
+  visit path_to(page_name)
+end
+
+When /^(?:|I )visit (\/.+)$/ do |page_path|
+  visit page_path
+end
+
+When /^(?:|I )press "([^"]*)"(?: within "([^"]*)")?$/ do |button, selector|
+  with_scope(selector) do
+    click_button(button)
+  end
+end
+
+When /^(?:|I )follow "([^"]*)"(?: within "([^"]*)")?$/ do |link, selector|
+  with_scope(selector) do
+    click_link(link)
+  end
+end
+
+When /^(?:|I )fill in "([^"]*)" with "([^"]*)"(?: within "([^"]*)")?$/ do |field, value, selector|
+  with_scope(selector) do
+    fill_in(field, :with => value)
+  end
+end
+
+When /^(?:|I )fill in "([^"]*)" for "([^"]*)"(?: within "([^"]*)")?$/ do |value, field, selector|
+  with_scope(selector) do
+    fill_in(field, :with => value)
+  end
+end
+
+# Use this to fill in an entire form with data from a table. Example:
+#
+#   When I fill in the following:
+#     | Account Number | 5002       |
+#     | Expiry date    | 2009-11-01 |
+#     | Note           | Nice guy   |
+#     | Wants Email?   |            |
+#
+# TODO: Add support for checkbox, select og option
+# based on naming conventions.
+#
+When /^(?:|I )fill in the following(?: within "([^"]*)")?:$/ do |selector, fields|
+  with_scope(selector) do
+    fields.rows_hash.each do |name, value|
+      When %{I fill in "#{name}" with "#{value}"}
+    end
+  end
+end
+
+When /^(?:|I )select "([^"]*)" from "([^"]*)"(?: within "([^"]*)")?$/ do |value, field, selector|
+  with_scope(selector) do
+    select(value, :from => field)
+  end
+end
+
+When /^(?:|I )check "([^"]*)"(?: within "([^"]*)")?$/ do |field, selector|
+  with_scope(selector) do
+    check(field)
+  end
+end
+
+When /^(?:|I )uncheck "([^"]*)"(?: within "([^"]*)")?$/ do |field, selector|
+  with_scope(selector) do
+    uncheck(field)
+  end
+end
+
+When /^(?:|I )choose "([^"]*)"(?: within "([^"]*)")?$/ do |field, selector|
+  with_scope(selector) do
+    choose(field)
+  end
+end
+
+When /^(?:|I )attach the file "([^"]*)" to "([^"]*)"(?: within "([^"]*)")?$/ do |path, field, selector|
+  with_scope(selector) do
+    attach_file(field, path)
+  end
+end
+
+Then /^(?:|I )should see JSON:$/ do |expected_json|
+  require 'json'
+  expected = JSON.pretty_generate(JSON.parse(expected_json))
+  actual   = JSON.pretty_generate(JSON.parse(response.body))
+  expected.should == actual
+end
+
+Then /^(?:|I )should see "([^"]*)"(?: within "([^"]*)")?$/ do |text, selector|
+  with_scope(selector) do
+    if page.respond_to? :should
+      page.should have_content(text)
+    else
+      assert page.has_content?(text)
+    end
+  end
+end
+
+Then /^(?:|I )should see \/([^\/]*)\/(?: within "([^"]*)")?$/ do |regexp, selector|
+  regexp = Regexp.new(regexp)
+  with_scope(selector) do
+    if page.respond_to? :should
+      page.should have_xpath('//*', :text => regexp)
+    else
+      assert page.has_xpath?('//*', :text => regexp)
+    end
+  end
+end
+
+Then /^(?:|I )should not see "([^"]*)"(?: within "([^"]*)")?$/ do |text, selector|
+  with_scope(selector) do
+    if page.respond_to? :should
+      page.should have_no_content(text)
+    else
+      assert page.has_no_content?(text)
+    end
+  end
+end
+
+Then /^(?:|I )should not see \/([^\/]*)\/(?: within "([^"]*)")?$/ do |regexp, selector|
+  regexp = Regexp.new(regexp)
+  with_scope(selector) do
+    if page.respond_to? :should
+      page.should have_no_xpath('//*', :text => regexp)
+    else
+      assert page.has_no_xpath?('//*', :text => regexp)
+    end
+  end
+end
+
+Then /^the "([^"]*)" field(?: within "([^"]*)")? should contain "([^"]*)"$/ do |field, selector, value|
+  with_scope(selector) do
+    field = find_field(field)
+    field_value = (field.tag_name == 'textarea') ? field.text : field.value
+    if field_value.respond_to? :should
+      field_value.should =~ /#{value}/
+    else
+      assert_match(/#{value}/, field_value)
+    end
+  end
+end
+
+Then /^the "([^"]*)" field(?: within "([^"]*)")? should not contain "([^"]*)"$/ do |field, selector, value|
+  with_scope(selector) do
+    field = find_field(field)
+    field_value = (field.tag_name == 'textarea') ? field.text : field.value
+    if field_value.respond_to? :should_not
+      field_value.should_not =~ /#{value}/
+    else
+      assert_no_match(/#{value}/, field_value)
+    end
+  end
+end
+
+Then /^the "([^"]*)" checkbox(?: within "([^"]*)")? should be checked$/ do |label, selector|
+  with_scope(selector) do
+    field_checked = find_field(label)['checked']
+    if field_checked.respond_to? :should
+      field_checked.should be_true
+    else
+      assert field_checked
+    end
+  end
+end
+
+Then /^the "([^"]*)" checkbox(?: within "([^"]*)")? should not be checked$/ do |label, selector|
+  with_scope(selector) do
+    field_checked = find_field(label)['checked']
+    if field_checked.respond_to? :should
+      field_checked.should be_false
+    else
+      assert !field_checked
+    end
+  end
+end
+ 
+Then /^(?:|I )should be on (.+)$/ do |page_name|
+  current_path = URI.parse(current_url).path
+  if current_path.respond_to? :should
+    current_path.should == path_to(page_name)
+  else
+    assert_equal path_to(page_name), current_path
+  end
+end
+
+Then /^(?:|I )should have the following query string:$/ do |expected_pairs|
+  query = URI.parse(current_url).query
+  actual_params = query ? CGI.parse(query) : {}
+  expected_params = {}
+  expected_pairs.rows_hash.each_pair{|k,v| expected_params[k] = v.split(',')} 
+  
+  if actual_params.respond_to? :should
+    actual_params.should == expected_params
+  else
+    assert_equal expected_params, actual_params
+  end
+end
+
+Then /^I save and open the page$/ do
+  save_and_open_page
+end
+
+Then /^show me the page$/ do
+  save_and_open_page
+end

features/support/env.rb

+require 'capybara/cucumber'
+require 'test/unit/assertions'
+World(Test::Unit::Assertions)

features/support/paths.rb

+module NavigationHelpers
+  # Maps a name to a path. Used by the
+  #
+  #   When /^I go to (.+)$/ do |page_name|
+  #
+  # step definition in web_steps.rb
+  #
+  def path_to(page_name)
+    case page_name
+
+    when /the new user page/
+      '/users/new'
+    when /the home\s?page/
+      '/'
+
+    # Add more mappings here.
+    # Here is an example that pulls values out of the Regexp:
+    #
+    #   when /^(.*)'s profile page$/i
+    #     user_profile_path(User.find_by_login($1))
+
+    else
+      begin
+        page_name =~ /the (.*) page/
+        path_components = $1.split(/\s+/)
+        self.send(path_components.push('path').join('_').to_sym)
+      rescue Object => e
+        raise "Can't find mapping from \"#{page_name}\" to a path.\n" +
+          "Now, go and add a mapping in #{__FILE__}"
+      end
+    end
+  end
+end
+
+World(NavigationHelpers)

features/support/rails.rb

+PROJECT_ROOT     = File.expand_path(File.join(File.dirname(__FILE__), '..', '..')).freeze
+TEMP_ROOT        = File.join(PROJECT_ROOT, 'tmp').freeze
+APP_NAME         = 'testapp'.freeze
+CUC_RAILS_ROOT   = File.join(TEMP_ROOT, APP_NAME).freeze
+
+Before do
+  FileUtils.rm_rf(TEMP_ROOT)
+  FileUtils.mkdir_p(CUC_RAILS_ROOT)
+  Dir.chdir(PROJECT_ROOT)
+end