1 files changed, 24 insertions, 24 deletions

diff --git a/crates/ide_assists/src/utils.rs b/crates/ide_assists/src/utils.rs
index 0dcf20c61..fc7caee04 100644
--- a/crates/ide_assists/src/utils.rs
+++ b/crates/ide_assists/src/utils.rs
@@ -17,7 +17,7 @@ use syntax::{
     ast::AttrsOwner,
     ast::NameOwner,
     ast::{self, edit, make, ArgListOwner, GenericParamsOwner},
-    AstNode, Direction, SmolStr,
+    ted, AstNode, Direction, SmolStr,
     SyntaxKind::*,
     SyntaxNode, TextSize, T,
 };
@@ -128,43 +128,43 @@ pub fn add_trait_assoc_items_to_impl(
     sema: &hir::Semantics<ide_db::RootDatabase>,
     items: Vec<ast::AssocItem>,
     trait_: hir::Trait,
-    impl_def: ast::Impl,
+    impl_: ast::Impl,
     target_scope: hir::SemanticsScope,
 ) -> (ast::Impl, ast::AssocItem) {
-    let impl_item_list = impl_def.assoc_item_list().unwrap_or_else(make::assoc_item_list);
-
-    let n_existing_items = impl_item_list.assoc_items().count();
     let source_scope = sema.scope_for_def(trait_);
     let ast_transform = QualifyPaths::new(&target_scope, &source_scope)
-        .or(SubstituteTypeParams::for_trait_impl(&source_scope, trait_, impl_def.clone()));
+        .or(SubstituteTypeParams::for_trait_impl(&source_scope, trait_, impl_.clone()));
 
     let items = items
         .into_iter()
         .map(|it| it.clone_for_update())
         .inspect(|it| ast_transform::apply(&*ast_transform, it))
-        .map(|it| match it {
-            ast::AssocItem::Fn(def) => ast::AssocItem::Fn(add_body(def)),
-            ast::AssocItem::TypeAlias(def) => ast::AssocItem::TypeAlias(def.remove_bounds()),
-            _ => it,
-        })
-        .map(|it| edit::remove_attrs_and_docs(&it));
-
-    let new_impl_item_list = impl_item_list.append_items(items);
-    let new_impl_def = impl_def.with_assoc_item_list(new_impl_item_list);
-    let first_new_item =
-        new_impl_def.assoc_item_list().unwrap().assoc_items().nth(n_existing_items).unwrap();
-    return (new_impl_def, first_new_item);
-
-    fn add_body(fn_def: ast::Fn) -> ast::Fn {
-        match fn_def.body() {
-            Some(_) => fn_def,
-            None => {
+        .map(|it| edit::remove_attrs_and_docs(&it).clone_subtree().clone_for_update());
+
+    let res = impl_.clone_for_update();
+
+    let assoc_item_list = res.get_or_create_assoc_item_list();
+    let mut first_item = None;
+    for item in items {
+        first_item.get_or_insert_with(|| item.clone());
+        match &item {
+            ast::AssocItem::Fn(fn_) if fn_.body().is_none() => {
                 let body = make::block_expr(None, Some(make::ext::expr_todo()))
                     .indent(edit::IndentLevel(1));
-                fn_def.with_body(body)
+                ted::replace(fn_.get_or_create_body().syntax(), body.clone_for_update().syntax())
             }
+            ast::AssocItem::TypeAlias(type_alias) => {
+                if let Some(type_bound_list) = type_alias.type_bound_list() {
+                    type_bound_list.remove()
+                }
+            }
+            _ => {}
         }
+
+        assoc_item_list.add_item(item)
     }
+
+    (res, first_item.unwrap())
 }
 
 #[derive(Clone, Copy, Debug)]