Accessibility: compare checker results after each recheck (#1250)

* Compare accessibility checks after document fixes

* Assert both pre-fix title findings in comparison test

crates/ui-egui/src/a11y_ui.rs

@@ -45,6 +45,9 @@ impl Default for A11yOptions {
 #[derive(Clone, Debug, Default)]
 pub struct A11yState {
     pub report: Option<(DocId, Report)>,
+    /// The prior check of the same document with the same checker options.
+    pub previous: Option<(DocId, Report)>,
+    pub options: Option<Options>,
     /// Collapsed categories and expanded rules.
     pub collapsed: BTreeSet<Category>,
     pub expanded: BTreeSet<Rule>,
@@ -191,6 +194,26 @@ pub(crate) fn panel(ui: &mut egui::Ui, t: &Tokens, state: &mut A11yState, doc: D
             }
         });
     });
+    if let Some((_, previous)) = state.previous.as_ref().filter(|(d, _)| *d == doc) {
+        egui::CollapsingHeader::new(tl!("Compare")).default_open(true).show(ui, |ui| {
+            for status in [Status::Passed, Status::Failed, Status::Manual, Status::Skipped] {
+                ui.label(format!("{}: {} → {}", tl!(status.label()), previous.count(status), report.count(status)));
+            }
+            for current in &report.results {
+                let Some(prior) = previous.result(current.rule) else { continue };
+                if prior.status != current.status || prior.findings.len() != current.findings.len() {
+                    ui.label(format!(
+                        "{}: {} ({}) → {} ({})",
+                        tl!(current.rule.name()),
+                        tl!(prior.status.label()),
+                        prior.findings.len(),
+                        tl!(current.status.label()),
+                        current.findings.len()
+                    ));
+                }
+            }
+        });
+    }
     ui.add_space(6.0);
     for c in Category::ALL {
         let rules: Vec<_> = report.in_category(c).collect();
@@ -331,6 +354,9 @@ impl PdfCraftApp {
             r.findings.clear();
         }
         let failed = report.count(Status::Failed);
+        self.a11y.previous =
+            if self.a11y.options.as_ref() == Some(&options) { self.a11y.report.take().filter(|(prior_id, _)| *prior_id == id) } else { None };
+        self.a11y.options = Some(options);
         self.a11y.report = Some((id, report));
         self.right = Some(RightPanel::Accessibility);
         self.notify(if failed == 0 {

crates/ui-egui/tests/accessibility.rs

@@ -61,10 +61,13 @@ fn checking_fixing_skipping_and_reporting() {
     h.get_by_label("Fix").click();
     h.run_steps(3);
     assert_eq!(status(&h, Rule::Title), Status::Passed);
+    assert_eq!(h.state().a11y.previous.as_ref().unwrap().1.result(Rule::Title).unwrap().status, Status::Failed);
     assert!(matches!(h.state().dialog, Some(Dialog::Properties(_))));
     assert_eq!(h.state().window_title, "notes — PdfCraft");
     h.state_mut().dialog = None;
     h.run_steps(2);
+    h.get_by_label("Compare");
+    h.get_by_label_contains("Title: Failed (2) → Passed (0)");
     // Skip a rule; it stays skipped when checking again.
     right_click(&mut h, "Tagged PDF - Failed");
     h.get_by_label("Skip Rule").click();

parity/acrobat-features.toml

@@ -8413,9 +8413,9 @@ tier = "P1"
 milestone = "M12"
 status = "shipped"
 commands = ["a11y.check"]
-tools = ["accessibility_fix"]
-evidence = ["crates/ui-egui/tests/accessibility.rs::checking_fixing_skipping_and_reporting", "crates/automation/tests/automation.rs::accessibility_check_report_and_fixes_through_tools"]
-notes = "right-click a rule: Fix (language via Document Properties, title, tab order), Skip Rule (kept on Check Again), Explain, Check Again, Show Report, Options"
+tools = ["accessibility_fix", "accessibility_review_record"]
+evidence = ["crates/ui-egui/tests/accessibility.rs::checking_fixing_skipping_and_reporting", "crates/automation/tests/automation.rs::accessibility_check_report_and_fixes_through_tools", "crates/automation/tests/automation.rs::accessibility_review_record_compares_two_versions_without_changing_them"]
+notes = "right-click a rule: Fix (language via Document Properties, title, tab order), Skip Rule (kept on Check Again), Explain, Check Again, Show Report, Options. The panel compares outcome counts and changed rules with the previous check of the same document and options; the headless review record compares two open revisions."
 
 [[feature]]
 id = "a11y.rule-permission-flag"