capybara_setup.rb in capybara-screenshot-diff-0.2.1

- old
+ new

@@ -1,9 +1,14 @@
 require 'capybara'
 require 'capybara/screenshot/diff/image_compare'
+require 'action_controller'
+require 'action_dispatch'
 
-# Add the `screenshot`method to ActionDispatch::IntegrationTest
+# TODO(uwe): Move this code to module Capybara::Screenshot::Diff::TestMethods,
+#            and use Module#prepend/include to insert.
+# Add the `screenshot` method to ActionDispatch::IntegrationTest
+# rubocop:disable Metrics/ClassLength
 class ActionDispatch::IntegrationTest
   ON_WINDOWS = RbConfig::CONFIG['host_os'] =~ /mswin|mingw|cygwin/
   SILENCE_ERRORS = ON_WINDOWS ? '2>nul' : '2>/dev/null'
 
   def self.os_name
@@ -17,26 +22,55 @@
     else
       'unknown'
     end
   end
 
-  def self.screenshot_dir
+  def self.screenshot_root
+    Capybara::Screenshot.screenshot_root ||
+        (defined?(Rails.root) && Rails.root) || File.expand_path('.')
+  end
+
+  def self.screenshot_area
     parts = ['doc/screenshots']
     parts << Capybara.default_driver.to_s if Capybara::Screenshot.add_driver_path
     parts << os_name if Capybara::Screenshot.add_os_path
     File.join parts
   end
 
-  def self.screenshot_dir_abs
-    "#{Rails.root}/#{screenshot_dir}".freeze
+  def self.screenshot_area_abs
+    "#{screenshot_root}/#{screenshot_area}".freeze
   end
 
+  def initialize(*)
+    super
+    @screenshot_counter = nil
+    @screenshot_group = nil
+    @screenshot_section = nil
+    @test_screenshot_errors = nil
+    @test_screenshots = nil
+  end
+
+  def group_parts
+    parts = []
+    parts << @screenshot_section if @screenshot_section.present?
+    parts << @screenshot_group if @screenshot_group.present?
+    parts
+  end
+
+  def full_name(name)
+    File.join group_parts.<<(name).map(&:to_s)
+  end
+
+  def screenshot_dir
+    File.join [self.class.screenshot_area] + group_parts
+  end
+
   setup do
     if Capybara::Screenshot.window_size
       if Capybara.default_driver == :selenium
         page.driver.browser.manage.window.resize_to(*Capybara::Screenshot.window_size)
-      else
+      elsif Capybara.default_driver == :poltergeist
         page.driver.resize(*Capybara::Screenshot.window_size)
       end
     end
   end
 
@@ -45,64 +79,102 @@
       @test_screenshots.each { |args| assert_image_not_changed(*args) }
     end
     fail(@test_screenshot_errors.join("\n\n")) if @test_screenshot_errors
   end
 
+  def screenshot_section(name)
+    @screenshot_section = name.to_s
+  end
+
   def screenshot_group(name)
-    @screenshot_group = name
+    @screenshot_group = name.to_s
     @screenshot_counter = 0
-    FileUtils.rm_rf "#{self.class.screenshot_dir_abs}/#{name}" if name.present?
+    return unless Capybara::Screenshot.active? && name.present?
+    FileUtils.rm_rf screenshot_dir
   end
 
   def screenshot(name)
-    return unless Capybara::Screenshot.enabled || (Capybara::Screenshot.enabled.nil? && Capybara::Screenshot::Diff.enabled)
+    return unless Capybara::Screenshot.active?
     if Capybara.default_driver == :selenium && Capybara::Screenshot.window_size
       return unless page.driver.browser.manage.window
           .size == Selenium::WebDriver::Dimension.new(*Capybara::Screenshot.window_size)
     end
     if @screenshot_counter
       name = "#{'%02i' % @screenshot_counter}_#{name}"
       @screenshot_counter += 1
     end
-    name = "#{@screenshot_group}/#{name}" if @screenshot_group.present?
-    file_name = "#{self.class.screenshot_dir_abs}/#{name}.png"
-    org_name = "#{self.class.screenshot_dir_abs}/#{name}_0.png~"
-    new_name = "#{self.class.screenshot_dir_abs}/#{name}_1.png~"
+    name = full_name(name)
+    file_name = "#{self.class.screenshot_area_abs}/#{name}.png"
+    org_name = "#{self.class.screenshot_area_abs}/#{name}_0.png~"
+    new_name = "#{self.class.screenshot_area_abs}/#{name}_1.png~"
 
     FileUtils.mkdir_p File.dirname(file_name)
-    svn_file_name = "#{self.class.screenshot_dir_abs}/.svn/text-base/#{name}.png.svn-base"
+    svn_file_name = "#{self.class.screenshot_area_abs}/.svn/text-base/#{name}.png.svn-base"
     if File.exist?(svn_file_name)
       committed_file_name = svn_file_name
     else
       svn_info = `svn info #{file_name} #{SILENCE_ERRORS}`
       if svn_info.present?
-        wc_root = svn_info.slice /(?<=Working Copy Root Path: ).*$/
-        checksum = svn_info.slice /(?<=Checksum: ).*$/
+        wc_root = svn_info.slice(/(?<=Working Copy Root Path: ).*$/)
+        checksum = svn_info.slice(/(?<=Checksum: ).*$/)
         if checksum
           committed_file_name = "#{wc_root}/.svn/pristine/#{checksum[0..1]}/#{checksum}.svn-base"
         end
       else
         committed_file_name = org_name
-        `git show HEAD~0:#{self.class.screenshot_dir}/#{name}.png > #{committed_file_name} #{SILENCE_ERRORS}`
+        `git show HEAD~0:#{self.class.screenshot_area}/#{name}.png > #{committed_file_name} #{SILENCE_ERRORS}`
         if File.size(committed_file_name) == 0
           FileUtils.rm_f committed_file_name
         end
       end
     end
+    take_stable_screenshot(file_name)
+    return unless committed_file_name && File.exist?(committed_file_name)
+    (@test_screenshots ||= []) << [caller[0], name, file_name, committed_file_name, new_name, org_name]
+  end
+
+  IMAGE_WAIT_SCRIPT = <<EOF.freeze
+function pending_image() {
+  var images = document.images;
+  for (var i = 0; i < images.length; i++) {
+    if (!images[i].complete) {
+        return images[i].src;
+    }
+  }
+  return false;
+}()
+EOF
+
+  def assert_images_loaded(timeout: Capybara.default_max_wait_time)
+    return unless respond_to? :evaluate_script
+    start = Time.now
+    loop do
+      pending_image = evaluate_script IMAGE_WAIT_SCRIPT
+      break unless pending_image
+      assert (Time.now - start) < timeout,
+          "Image not loaded after #{timeout}s: #{pending_image.inspect}"
+      sleep 0.1
+    end
+  end
+
+  def take_stable_screenshot(file_name)
+    assert_images_loaded
     old_file_size = nil
     loop do
-      page.save_screenshot(file_name)
-      break if old_file_size == File.size(file_name)
-      old_file_size = File.size(file_name)
-      sleep 0.5
+      save_screenshot(file_name)
+      break unless Capybara::Screenshot.stability_time_limit
+      new_file_size = File.size(file_name)
+      break if new_file_size == old_file_size
+      old_file_size = new_file_size
+      sleep Capybara::Screenshot.stability_time_limit
     end
-    return unless File.exist?(committed_file_name)
-    (@test_screenshots ||= []) << [caller[0], name, file_name, committed_file_name, new_name, org_name]
   end
 
   def assert_image_not_changed(caller, name, file_name, committed_file_name, new_name, org_name)
-    if Capybara::Screenshot::Diff::ImageCompare.compare(file_name, committed_file_name, Capybara::Screenshot.window_size)
+    if Capybara::Screenshot::Diff::ImageCompare.compare(committed_file_name, file_name,
+        Capybara::Screenshot.window_size)
       (@test_screenshot_errors ||= []) <<
-          "Screenshot does not match for #{name.inspect}\n#{file_name}\n#{org_name}\n#{new_name}\nat #{caller}"
+          "Screenshot does not match for '#{name}'\n#{file_name}\n#{org_name}\n#{new_name}\nat #{caller}"
     end
   end
 end
+# rubocop:enable Metrics/ClassLength