Part of #394: headless tests for Hyphenation › Exceptions UI and layout.

Co-authored-by: Cursor <cursoragent@cursor.com>

crates/text/src/hyphen.rs

@@ -186,14 +186,20 @@ thread_local! {
     static TEST_OVERRIDE: std::cell::RefCell<Option<Exceptions>> = const { std::cell::RefCell::new(None) };
 }
 
+/// Run `f` with Preferences › Hyphenation › Exceptions applied on this thread only (tests).
+#[cfg(test)]
+pub(crate) fn with_hyphenation_exceptions_for_test(source: &str, f: impl FnOnce()) {
+    TEST_OVERRIDE.with(|c| *c.borrow_mut() = Some(parse_list(source)));
+    f();
+    TEST_OVERRIDE.with(|c| *c.borrow_mut() = None);
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
 
     fn with_exceptions(source: &str, f: impl FnOnce()) {
-        TEST_OVERRIDE.with(|c| *c.borrow_mut() = Some(parse_list(source)));
-        f();
-        TEST_OVERRIDE.with(|c| *c.borrow_mut() = None);
+        with_hyphenation_exceptions_for_test(source, f);
     }
 
     /// #394 Preferences › Hyphenation › Exceptions contract (parse + override).

crates/text/src/tests_typo.rs

@@ -415,6 +415,26 @@ fn hyphenated_layout_adds_hyphens() {
     }
 }
 
+/// Preferences › Hyphenation › Exceptions (#394): listing a word stops the layout from breaking it.
+#[test]
+fn hyphenation_exceptions_keep_listed_words_whole_in_layout() {
+    // Same copy as `hyphenated_layout_adds_hyphens` (known to produce soft hyphens at 120pt width).
+    let text = "Extraordinarily comprehensive typographical considerations notwithstanding everything.";
+    let mut t = area(text, style(14.0), Rect::new(0.0, 0.0, 120.0, 600.0), Justify::Left);
+    t.para.hyphenate = true;
+    let with_breaks = layout(db(), &t);
+    let hyphens = |l: &TextLayout| l.glyphs.iter().filter(|g| g.len == 0).count();
+    assert!(hyphens(&with_breaks) > 0, "pattern produces soft hyphens");
+    hyphen::with_hyphenation_exceptions_for_test(
+        "extraordinarily, comprehensive, typographical, considerations, notwithstanding, everything",
+        || {
+            let blocked = layout(db(), &t);
+            assert_eq!(hyphens(&blocked), 0, "every long word listed: no soft hyphens");
+            assert!(blocked.lines.len() >= with_breaks.lines.len());
+        },
+    );
+}
+
 #[test]
 fn soft_hyphen_is_invisible_mid_line() {
     let l = layout(db(), &TextObject::point(Point::ZERO, "co\u{00AD}operate", style(20.0)));

crates/ui-egui/src/prefs_dialog.rs

@@ -577,4 +577,28 @@ mod tests {
             assert!(PREF_SPECS.iter().any(|s| s.category == *c));
         }
     }
+
+    /// Preferences › Hyphenation › Exceptions (#394): OK on the dialog pushes the list into the
+    /// hyphenator the same way `prefs.set` does (no need to drive the live Preferences window).
+    #[test]
+    fn hyphenation_exceptions_dialog_ok_reaches_the_hyphenator() {
+        struct Clear;
+        impl Drop for Clear {
+            fn drop(&mut self) {
+                vectorcraft_text::set_hyphenation_exceptions("");
+            }
+        }
+        let _clear = Clear;
+        let mut a = app();
+        open(&mut a, Some("Hyphenation"));
+        let d = a.ui.dialog.as_mut().unwrap();
+        assert_eq!(d.str("__category"), "Hyphenation");
+        d.fields.insert("hyphenationExceptions".into(), json!("typography, hap-pen"));
+        confirm(&mut a).unwrap();
+        assert!(a.ui.dialog.is_none());
+        assert_eq!(a.session.prefs.hyphenation_exceptions, "typography, hap-pen");
+        assert_eq!(vectorcraft_text::hyphenation_exceptions(), "typography, hap-pen");
+        assert!(vectorcraft_text::hyphen::hyphen_points("typography").is_empty());
+        assert_eq!(vectorcraft_text::hyphen::hyphen_points("happen"), vec![3]);
+    }
 }