more type safety

3 files changed, 29 insertions, 4 deletions

diff --git a/crates/ra_assists/src/ast_editor.rs b/crates/ra_assists/src/ast_editor.rs
index 7ef58aa8e..13ee82879 100644
--- a/crates/ra_assists/src/ast_editor.rs
+++ b/crates/ra_assists/src/ast_editor.rs
@@ -137,9 +137,32 @@ pub struct AstBuilder<N: AstNode> {
 }
 
 impl AstBuilder<ast::NamedField> {
-    pub fn from_text(text: &str) -> TreeArc<ast::NamedField> {
+    fn from_text(text: &str) -> TreeArc<ast::NamedField> {
         ast_node_from_file_text(&format!("fn f() {{ S {{ {}, }} }}", text))
     }
+
+    pub fn from_pieces(name: &ast::NameRef, expr: Option<&ast::Expr>) -> TreeArc<ast::NamedField> {
+        match expr {
+            Some(expr) => Self::from_text(&format!("{}: {}", name.syntax(), expr.syntax())),
+            None => Self::from_text(&name.syntax().to_string()),
+        }
+    }
+}
+
+impl AstBuilder<ast::Expr> {
+    fn from_text(text: &str) -> TreeArc<ast::Expr> {
+        ast_node_from_file_text(&format!("fn f() {{ {}; }}", text))
+    }
+
+    pub fn unit() -> TreeArc<ast::Expr> {
+        Self::from_text("()")
+    }
+}
+
+impl AstBuilder<ast::NameRef> {
+    pub fn new(text: &str) -> TreeArc<ast::NameRef> {
+        ast_node_from_file_text(&format!("fn f() {{ {}; }}", text))
+    }
 }
 
 fn ast_node_from_file_text<N: AstNode>(text: &str) -> TreeArc<N> {
diff --git a/crates/ra_assists/src/fill_struct_fields.rs b/crates/ra_assists/src/fill_struct_fields.rs
index 302d62ab1..54b70e17d 100644
--- a/crates/ra_assists/src/fill_struct_fields.rs
+++ b/crates/ra_assists/src/fill_struct_fields.rs
@@ -37,8 +37,10 @@ pub(crate) fn fill_struct_fields(mut ctx: AssistCtx<impl HirDatabase>) -> Option
         };
 
         for field in fields {
-            let field =
-                AstBuilder::<ast::NamedField>::from_text(&format!("{}: ()", field.name(db)));
+            let field = AstBuilder::<ast::NamedField>::from_pieces(
+                &AstBuilder::<ast::NameRef>::new(&field.name(db).to_string()),
+                Some(&AstBuilder::<ast::Expr>::unit()),
+            );
             ast_editor.append_field(&field);
         }
 
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index 3151b1c44..60b4d5c63 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -37,7 +37,7 @@ pub struct AssistAction {
     pub target: Option<TextRange>,
 }
 
-/// Return all the assists applicable at the given position.
+/// Return all the assists eapplicable at the given position.
 ///
 /// Assists are returned in the "unresolved" state, that is only labels are
 /// returned, without actual edits.