2 files changed, 20 insertions, 0 deletions

diff --git a/crates/syntax/src/ast/edit.rs b/crates/syntax/src/ast/edit.rs
index 45cf31f13..dda0a0319 100644
--- a/crates/syntax/src/ast/edit.rs
+++ b/crates/syntax/src/ast/edit.rs
@@ -93,6 +93,22 @@ where
     }
 }
 
+impl ast::Impl {
+    #[must_use]
+    pub fn with_assoc_item_list(&self, items: ast::AssocItemList) -> ast::Impl {
+        let mut to_insert: ArrayVec<[SyntaxElement; 2]> = ArrayVec::new();
+        if let Some(old_items) = self.assoc_item_list() {
+            let to_replace: SyntaxElement = old_items.syntax().clone().into();
+            to_insert.push(items.syntax().clone().into());
+            self.replace_children(single_node(to_replace), to_insert)
+        } else {
+            to_insert.push(make::tokens::single_space().into());
+            to_insert.push(items.syntax().clone().into());
+            self.insert_children(InsertPosition::Last, to_insert)
+        }
+    }
+}
+
 impl ast::AssocItemList {
     #[must_use]
     pub fn append_items(
diff --git a/crates/syntax/src/ast/make.rs b/crates/syntax/src/ast/make.rs
index 6868feed9..4a0ffcbb0 100644
--- a/crates/syntax/src/ast/make.rs
+++ b/crates/syntax/src/ast/make.rs
@@ -21,6 +21,10 @@ pub fn ty(text: &str) -> ast::Type {
     ast_from_text(&format!("impl {} for D {{}};", text))
 }
 
+pub fn assoc_item_list() -> ast::AssocItemList {
+    ast_from_text("impl C for D {};")
+}
+
 pub fn path_segment(name_ref: ast::NameRef) -> ast::PathSegment {
     ast_from_text(&format!("use {};", name_ref))
 }