capybara_setup.rb in capybara-screenshot-diff-0.6.0

- old
+ new

@@ -95,12 +95,12 @@
       end
     end
 
     teardown do
       if Capybara::Screenshot::Diff.enabled && @test_screenshots
-        test_screenshot_errors =
-          @test_screenshots.map { |args| assert_image_not_changed(*args) }.compact
+        test_screenshot_errors = @test_screenshots
+          .map { |caller, name, compare| assert_image_not_changed(caller, name, compare) }.compact
         fail(test_screenshot_errors.join("\n\n")) if test_screenshot_errors.any?
       end
     end
 
     def screenshot_section(name)
@@ -112,39 +112,39 @@
       @screenshot_counter = 0
       return unless Capybara::Screenshot.active? && name.present?
       FileUtils.rm_rf screenshot_dir
     end
 
-    def screenshot(name)
+    def screenshot(name, color_distance_limit: Capybara::Screenshot::Diff.color_distance_limit,
+        area_size_limit: nil)
       return unless Capybara::Screenshot.active?
       return if window_size_is_wrong?
       if @screenshot_counter
         name = "#{format('%02i', @screenshot_counter)}_#{name}"
         @screenshot_counter += 1
       end
       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)
-      committed_file_name = check_vcs(name, file_name, org_name)
-      previous_file_exists = committed_file_name && File.exist?(committed_file_name)
-      previous_size = File.size(committed_file_name) if previous_file_exists
-      take_stable_screenshot(file_name, previous_size)
-      return unless previous_file_exists
-      (@test_screenshots ||= []) << [caller[0], name, file_name, committed_file_name, new_name, org_name]
+      committed_file_name = check_vcs(name, file_name)
+      comparison = Capybara::Screenshot::Diff::ImageCompare.new(committed_file_name, file_name,
+          dimensions: Capybara::Screenshot.window_size, color_distance_limit: color_distance_limit,
+          area_size_limit: area_size_limit)
+      take_stable_screenshot(comparison)
+      return unless comparison.old_file_exists?
+      (@test_screenshots ||= []) << [caller[0], name, comparison]
     end
 
     private def window_size_is_wrong?
       selenium? && Capybara::Screenshot.window_size &&
         (!page.driver.chrome? || ON_WINDOWS) && # TODO(uwe): Allow for Chrome when it works
         page.driver.browser.manage.window.size !=
           Selenium::WebDriver::Dimension.new(*Capybara::Screenshot.window_size)
     end
 
-    def check_vcs(name, file_name, org_name)
+    private def check_vcs(name, file_name)
       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}`
@@ -153,21 +153,25 @@
           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
-          redirect_target = "#{committed_file_name} #{SILENCE_ERRORS}"
-          `git show HEAD~0:./#{self.class.screenshot_area}/#{name}.png > #{redirect_target}`
-          if File.size(committed_file_name) == 0
-            FileUtils.rm_f committed_file_name
-          end
+          committed_file_name = restore_git_revision(name,
+              Capybara::Screenshot::Diff::ImageCompare.annotated_old_file_name(file_name))
         end
       end
       committed_file_name
     end
 
+    private def restore_git_revision(name, org_name)
+      committed_file_name = org_name
+      redirect_target = "#{committed_file_name} #{SILENCE_ERRORS}"
+      `git show HEAD~0:./#{self.class.screenshot_area}/#{name}.png > #{redirect_target}`
+      FileUtils.rm_f(committed_file_name) if File.size(committed_file_name) == 0
+      committed_file_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) {
@@ -188,32 +192,37 @@
             "Images not loaded after #{timeout}s: #{pending_image.inspect}"
         sleep 0.1
       end
     end
 
-    def take_stable_screenshot(file_name, original_file_size = nil)
+    private def take_stable_screenshot(comparison)
       assert_images_loaded
-      old_file_size = original_file_size
+      previous_file_size = comparison.old_file_size
       screeenshot_started_at = last_image_change_at = Time.now
       loop do
-        save_screenshot(file_name)
+        save_screenshot(comparison.new_file_name)
 
         # TODO(uwe): Remove when chromedriver take right size screenshots
-        reduce_retina_image_size(file_name)
+        reduce_retina_image_size(comparison.new_file_name)
         # EMXIF
 
         break unless Capybara::Screenshot.stability_time_limit
-        new_file_size = File.size(file_name)
-        break if new_file_size == original_file_size
-        break if new_file_size == old_file_size &&
-            (Time.now - last_image_change_at) > Capybara::Screenshot.stability_time_limit
-        last_image_change_at = Time.now if new_file_size != old_file_size
-        old_file_size = new_file_size
-        sleep 0.1
+        break if comparison.quick_equal?
 
+        if comparison.new_file_size == previous_file_size
+          if (Time.now - last_image_change_at) > Capybara::Screenshot.stability_time_limit
+            break
+          end
+        else
+          last_image_change_at = Time.now
+        end
+
         assert (Time.now - screeenshot_started_at) < Capybara.default_max_wait_time,
             "Could not get stable screenshot within #{Capybara.default_max_wait_time}s"
+
+        previous_file_size = comparison.new_file_size
+        comparison.reset
       end
     end
 
     private def reduce_retina_image_size(file_name)
       return if !self.class.macos? || !selenium? || !Capybara::Screenshot.window_size
@@ -223,14 +232,16 @@
       height = (width * saved_image.height) / saved_image.width
       resized_image = saved_image.resample_bilinear(width, height)
       resized_image.save(file_name)
     end
 
-    def assert_image_not_changed(caller, name, file_name, committed_file_name, new_name, org_name)
-      if Capybara::Screenshot::Diff::ImageCompare.compare(committed_file_name, file_name,
-          Capybara::Screenshot.window_size)
-        "Screenshot does not match for '#{name}'\n#{file_name}\n#{org_name}\n#{new_name}\nat #{caller}"
-      end
+    def assert_image_not_changed(caller, name, comparison)
+      return unless comparison.different?
+      "Screenshot does not match for '#{name}' (area: #{comparison.size} #{comparison.dimensions}" \
+        ", max_color_distance: #{comparison.max_color_distance.round(1)})\n" \
+        "#{comparison.new_file_name}\n#{comparison.annotated_old_file_name}\n" \
+        "#{comparison.annotated_new_file_name}\n" \
+        "at #{caller}"
     end
   end
 end
 # rubocop:enable Metrics/ClassLength