Fix append cursor location when selection anchor is at end of document (helix-editor#4147)

Author: Graicc

helix-term/src/commands.rs

@@ -2225,7 +2225,7 @@ fn append_mode(cx: &mut Context) {
         .iter()
         .last()
         .expect("selection should always have at least one range");
-    if !last_range.is_empty() && last_range.head == end {
+    if !last_range.is_empty() && last_range.to() == end {
         let transaction = Transaction::change(
             doc.text(),
             [(end, end, Some(doc.line_ending.as_str().into()))].into_iter(),

helix-term/tests/test/movement.rs

@@ -86,6 +86,27 @@ async fn cursor_position_newly_opened_file() -> anyhow::Result<()> {
     Ok(())
 }
 
+#[tokio::test]
+async fn cursor_position_append_eof() -> anyhow::Result<()> {
+    // Selection is fowards
+    test((
+        "#[foo|]#",
+        "abar<esc>",
+        helpers::platform_line("#[foobar|]#\n").as_ref(),
+    ))
+    .await?;
+
+    // Selection is backwards
+    test((
+        "#[|foo]#",
+        "abar<esc>",
+        helpers::platform_line("#[foobar|]#\n").as_ref(),
+    ))
+    .await?;
+
+    Ok(())
+}
+
 #[tokio::test]
 async fn select_mode_tree_sitter_next_function_is_union_of_objects() -> anyhow::Result<()> {
     test_with_config(