fix: replace selected characters with visual r

tests/normal_editing.rs

@@ -42,6 +42,89 @@ fn keys(editor: &mut Editor, text: &str) {
     }
 }
 
+#[test]
+fn visual_r_replaces_selected_graphemes_as_one_undo_edit() {
+    let fixture = Fixture::new();
+    let source = "ae\u{301}👩‍🚀z\nrest\n";
+    let mut editor = fixture.editor(source);
+    keys(&mut editor, "lv2l");
+    assert_eq!(editor.mode(), Mode::Visual);
+    keys(&mut editor, "r界");
+    assert_eq!(editor.context().text, "a界界界\nrest\n");
+    assert_eq!(editor.mode(), Mode::Normal);
+    keys(&mut editor, "u");
+    assert_eq!(editor.context().text, source);
+    assert!(!editor.dirty());
+    keys(&mut editor, "U");
+    assert_eq!(editor.context().text, "a界界界\nrest\n");
+}
+
+#[test]
+fn visual_r_preserves_selected_newlines_in_both_directions_and_shapes() {
+    for (source, selection, expected) in [
+        ("ae\u{301}👩‍🚀z\n\nbc\nlast\n", "v2j", "QQQQ\n\nQc\nlast\n"),
+        ("ae\u{301}👩‍🚀z\n\nbc\nlast\n", "2jv2k", "QQQQ\n\nQc\nlast\n"),
+        ("ae\u{301}👩‍🚀z\n\nbc\nlast\n", "V2j", "QQQQ\n\nQQ\nlast\n"),
+        ("ab\ncd", "Vj", "QQ\nQQ"),
+        ("\n\n", "Vj", "\n\n"),
+    ] {
+        let fixture = Fixture::new();
+        let mut editor = fixture.editor(source);
+        keys(&mut editor, selection);
+        keys(&mut editor, "rQ");
+        assert_eq!(editor.context().text, expected, "{selection}");
+        assert_eq!(editor.mode(), Mode::Normal);
+        assert_eq!(editor.dirty(), source != expected);
+        keys(&mut editor, "u");
+        assert_eq!(editor.context().text, source);
+    }
+}
+
+#[test]
+fn visual_r_replaces_every_selection_and_restores_carets_on_undo() {
+    let fixture = Fixture::new();
+    let source = "abcd\nwxyz\n";
+    let mut editor = fixture.editor(source);
+    keys(&mut editor, "vl");
+    editor.handle(Input::Ctrl('e'));
+    let carets = editor.carets();
+    assert_eq!(editor.selection_count(), 2);
+    keys(&mut editor, "r界");
+    assert_eq!(editor.context().text, "界界cd\n界界yz\n");
+    assert_eq!(editor.selection_count(), 2);
+    keys(&mut editor, "u");
+    assert_eq!(editor.context().text, source);
+    assert_eq!(editor.carets(), carets);
+}
+
+#[test]
+fn visual_r_repeats_selection_intent_without_overwriting_the_clipboard() {
+    let fixture = Fixture::new();
+    let mut editor = fixture.editor("abc\nuvwxyz\n");
+    keys(&mut editor, "yyvlrQj0.");
+    assert_eq!(editor.context().text, "QQc\nQQwxyz\n");
+    keys(&mut editor, "4lv.");
+    assert_eq!(editor.context().text, "QQc\nQQwxQz\n");
+    keys(&mut editor, "P");
+    assert_eq!(editor.context().text, "QQc\nabc\nQQwxQz\n");
+}
+
+#[test]
+fn cancelled_and_identical_visual_replacements_preserve_redo() {
+    let fixture = Fixture::new();
+    let mut editor = fixture.editor("abc\n");
+    keys(&mut editor, "rQulvr");
+    editor.handle(Input::Escape);
+    assert_eq!(editor.mode(), Mode::Visual);
+    assert_eq!(editor.line_operator_pending(), None);
+    keys(&mut editor, "rb");
+    assert_eq!(editor.context().text, "abc\n");
+    assert_eq!(editor.mode(), Mode::Normal);
+    assert!(!editor.dirty());
+    keys(&mut editor, "U");
+    assert_eq!(editor.context().text, "Qbc\n");
+}
+
 #[test]
 fn change_and_delete_line_suffix_preserve_newlines_and_group_insert_undo() {
     for operation in ["C", "D", "9C", "9D"] {