Add function signature to CompletionItem detail

1 files changed, 22 insertions, 0 deletions

diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index 9ae620efd..21ca36265 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -366,6 +366,28 @@ impl Function {
             Some(comments)
         }
     }
+
+    pub fn label(&self, db: &impl HirDatabase) -> Option<String> {
+        let def_loc = self.def_id.loc(db);
+        let syntax = db.file_item(def_loc.source_item_id);
+        let node = ast::FnDef::cast(&syntax).expect("fn def should point to FnDef node");
+
+        let label: String = if let Some(body) = node.body() {
+            let body_range = body.syntax().range();
+            let label: String = node
+                .syntax()
+                .children()
+                .filter(|child| !child.range().is_subrange(&body_range)) // Filter out body
+                .filter(|child| ast::Comment::cast(child).is_none()) // Filter out comments
+                .map(|node| node.text().to_string())
+                .collect();
+            label
+        } else {
+            node.syntax().text().to_string()
+        };
+
+        Some(label.trim().to_owned())
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]