refactor: address multi-agent review findings

Reporter:
- Rename single-letter `d` to `difference` for readability
- Remove rescue ArgumentError in relative_path (fail fast per CLAUDE.md)

Script:
- Use reporter.finalize instead of manual File.write + render

Integration test:
- Extract visit to setup (DRY)
- Guard @report_path nil in teardown
- Use reporter.finalize instead of manual render

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: pftg

lib/capybara_screenshot_diff/reporters/html.rb

@@ -58,26 +58,24 @@ def self.template_path
       private
 
       def failure_entry_for(name, compare)
-        d = compare.difference
+        difference = compare.difference
         {
           name: name,
           original: relative_path(compare.base_image_path),
           new: relative_path(compare.image_path),
           base_diff: relative_path(compare.reporter.annotated_base_image_path),
           diff: relative_path(compare.reporter.annotated_image_path),
           heatmap: relative_path(compare.reporter.heatmap_diff_path),
-          diff_level: d.ratio && (d.ratio * 100).round(2),
-          area_size: d.region_area_size,
-          max_color_distance: d.meta[:max_color_distance]&.round(1)
+          diff_level: difference.ratio && (difference.ratio * 100).round(2),
+          area_size: difference.region_area_size,
+          max_color_distance: difference.meta[:max_color_distance]&.round(1)
         }
       end
 
       def relative_path(path)
         return unless path
 
         Pathname.new(path).relative_path_from(@report_dir).to_s
-      rescue ArgumentError
-        path.to_s
       end
 
       def write_report

scripts/generate_sample_report.rb

@@ -46,7 +46,6 @@
 end
 
 reporter.record(assertions + passing)
-File.write(output_path, reporter.render)
+reporter.finalize
 
-puts "Generated: #{output_path}"
 puts "Screenshots: #{reporter.failed} failed, #{reporter.passed} passed, #{reporter.total} total"

test/integration/report_screenshot_test.rb

@@ -4,44 +4,39 @@
 require "capybara_screenshot_diff/reporters/html"
 
 class ReportScreenshotTest < SystemTestCase
+  PERCEPTUAL_THRESHOLD = 2.0
+
   setup do
     skip "Run with RECORD_SCREENSHOTS=1 to update report fixtures" unless ENV["RECORD_SCREENSHOTS"]
     @report_path = Pathname.new("test/fixtures/app/sample_report.html")
     generate_sample_report
+    visit "/sample_report.html"
   end
 
   teardown do
-    FileUtils.rm_f(@report_path)
+    FileUtils.rm_f(@report_path) if @report_path
   end
 
-  # Perceptual threshold for antialiasing differences between runs
-  PERCEPTUAL_THRESHOLD = 2.0
-
   def test_report_both_view
-    visit "/sample_report.html"
     screenshot "report_both", perceptual_threshold: PERCEPTUAL_THRESHOLD
   end
 
   def test_report_base_view
-    visit "/sample_report.html"
     find("[data-view='base']").click
     screenshot "report_base", perceptual_threshold: PERCEPTUAL_THRESHOLD
   end
 
   def test_report_new_view
-    visit "/sample_report.html"
     find("[data-view='new']").click
     screenshot "report_new", perceptual_threshold: PERCEPTUAL_THRESHOLD
   end
 
   def test_report_heatmap_view
-    visit "/sample_report.html"
     find("[data-view='heatmap']").click
     screenshot "report_heatmap", perceptual_threshold: PERCEPTUAL_THRESHOLD
   end
 
   def test_report_annotated_both
-    visit "/sample_report.html"
     find("#annotate-toggle").click
     screenshot "report_annotated_both", perceptual_threshold: PERCEPTUAL_THRESHOLD
   end