fix: safe bugfixes and minor perf improvements

lib/capybara/screenshot/diff/browser_helpers.rb

@@ -85,7 +85,7 @@ def self.blur_from_focused_element
       JS
 
       def self.all_visible_regions_for(selector)
-        BrowserHelpers.session.all(selector, visible: true).map(&method(:region_for))
+        BrowserHelpers.session.all(selector, visible: true).map { |el| region_for(el) }
       end
 
       def self.region_for(element)

lib/capybara/screenshot/diff/reporters/default.rb

@@ -8,7 +8,7 @@ class Default
       def initialize(difference)
         @difference = difference
 
-        screenshot_format = difference.comparison.options[:screenshot_format] || comparison.new_image_path.extname.slice(1..-1)
+        screenshot_format = difference.comparison.options[:screenshot_format] || comparison.new_image_path.extname.delete_prefix(".").then { |ext| ext.empty? ? "png" : ext }
         @annotated_image_path = comparison.new_image_path.sub_ext(".diff.#{screenshot_format}")
         @annotated_base_image_path = comparison.base_image_path.sub_ext(".diff.#{screenshot_format}")
         @heatmap_diff_path = comparison.new_image_path.sub_ext(".heatmap.diff.#{screenshot_format}")

lib/capybara/screenshot/diff/screenshot_matcher.rb

@@ -83,7 +83,7 @@ def capture_screenshot(capture_options, comparison_options)
           screenshoter = if capture_options[:stability_time_limit]
             StableScreenshoter.new(capture_options, comparison_options)
           else
-            Diff.screenshoter.new(capture_options, comparison_options[:driver])
+            Diff.screenshoter.new(capture_options, comparison_options)
           end
           screenshoter.take_comparison_screenshot(@snapshot)
         end

lib/capybara/screenshot/diff/screenshoter.rb

@@ -8,9 +8,9 @@ module Screenshot
     class Screenshoter
       attr_reader :capture_options, :driver
 
-      def initialize(capture_options, driver)
+      def initialize(capture_options, comparison_options = {})
         @capture_options = capture_options
-        @driver = driver
+        @driver = Diff::Drivers.for(comparison_options)
       end
 
       def crop
@@ -101,7 +101,7 @@ def save_and_process_screenshot(screenshot_path)
         # Load saved screenshot and pre-process it
         process_screenshot(tmpfile.path, screenshot_path)
       ensure
-        File.unlink(tmpfile) if tmpfile
+        tmpfile&.close!
       end
 
       def capture_screenshot_at(snapshot)

lib/capybara/screenshot/diff/stable_screenshoter.rb

@@ -25,8 +25,7 @@ def initialize(capture_options, comparison_options = {})
 
           @comparison_options = comparison_options
 
-          driver = Diff::Drivers.for(@comparison_options)
-          @screenshoter = Diff.screenshoter.new(capture_options.except(:stability_time_limit), driver)
+          @screenshoter = Diff.screenshoter.new(capture_options.except(:stability_time_limit), @comparison_options)
         end
 
         # Takes a comparison screenshot ensuring page stability
@@ -61,14 +60,13 @@ def take_stable_screenshot(snapshot)
           # Cleanup all previous attempts for sure
           snapshot.cleanup_attempts!
 
-          0.step do |i|
-            # FIXME: it should be wait, and wait should be replaced with stability_time_limit
-            sleep(stability_time_limit) unless i == 0 # test prev_attempt_path is nil
-
+          loop do
             attempt_next_screenshot(snapshot)
 
             return true if attempt_successful?(snapshot)
             return false if timeout?(deadline_at)
+
+            sleep(stability_time_limit)
           end
         end
 

lib/capybara_screenshot_diff/dsl.rb

@@ -76,6 +76,13 @@ def screenshot(name, skip_stack_frames: 0, **options)
     # @see #screenshot
     alias_method :assert_matches_screenshot, :screenshot
 
+    # Asserts the current page has no visual changes from the baseline.
+    # Override in your base test class to add project-specific behavior
+    # (e.g., waiting for Turbo, default skip areas).
+    def assert_no_screenshot_changes(name, skip_stack_frames: 0, **opts)
+      screenshot(name, skip_stack_frames: skip_stack_frames + 1, **opts)
+    end
+
     private
 
     # Builds a screenshot assertion object that can be validated immediately or later.

test/unit/screenshoter_test.rb

@@ -10,7 +10,7 @@ class ScreenshoterTest < ActiveSupport::TestCase
       include CapybaraScreenshotDiff::DSLStub
 
       test "#take_screenshot without wait skips image loading" do
-        screenshoter = Screenshoter.new({wait: nil}, ::Minitest::Mock.new)
+        screenshoter = Screenshoter.new({wait: nil}, {driver: :chunky_png})
 
         mock = ::Minitest::Mock.new
         mock.expect(:save_screenshot, true) { |path| path.include?("01_a.png") }
@@ -27,7 +27,7 @@ class ScreenshoterTest < ActiveSupport::TestCase
       test "#take_screenshot with custom screenshot options" do
         screenshoter = Screenshoter.new(
           {wait: nil, capybara_screenshot_options: {full: true}},
-          ::Minitest::Mock.new
+          {driver: :chunky_png}
         )
 
         mock = ::Minitest::Mock.new
@@ -43,7 +43,7 @@ class ScreenshoterTest < ActiveSupport::TestCase
       end
 
       test "#prepare_page_for_screenshot without wait does not raise any error" do
-        screenshoter = Screenshoter.new({wait: nil}, ::Minitest::Mock.new)
+        screenshoter = Screenshoter.new({wait: nil}, {driver: :chunky_png})
 
         assert_nil screenshoter.prepare_page_for_screenshot(timeout: nil) # does not raise an error
       end