4 files changed, 39 insertions, 17 deletions

diff --git a/crates/ra_analysis/src/completion/complete_path.rs b/crates/ra_analysis/src/completion/complete_path.rs
index c73a083a4..4723a65a6 100644
--- a/crates/ra_analysis/src/completion/complete_path.rs
+++ b/crates/ra_analysis/src/completion/complete_path.rs
@@ -17,7 +17,7 @@ pub(super) fn complete_path(acc: &mut Completions, ctx: &CompletionContext) -> C
             let module_scope = module.scope(ctx.db)?;
             module_scope.entries().for_each(|(name, res)| {
                 CompletionItem::new(CompletionKind::Reference, name.to_string())
-                    .from_resolution(ctx.db, res)
+                    .from_resolution(ctx, res)
                     .add_to(acc)
             });
         }
@@ -113,4 +113,16 @@ mod tests {
             "Foo;Bar",
         );
     }
+
+    #[test]
+    fn dont_render_function_parens_in_use_item() {
+        check_reference_completion(
+            "
+            //- /lib.rs
+            mod m { pub fn foo() {} }
+            use crate::m::f<|>;
+            ",
+            "foo",
+        )
+    }
 }
diff --git a/crates/ra_analysis/src/completion/complete_scope.rs b/crates/ra_analysis/src/completion/complete_scope.rs
index cd98efe95..daf666505 100644
--- a/crates/ra_analysis/src/completion/complete_scope.rs
+++ b/crates/ra_analysis/src/completion/complete_scope.rs
@@ -34,7 +34,7 @@ pub(super) fn complete_scope(acc: &mut Completions, ctx: &CompletionContext) ->
         })
         .for_each(|(name, res)| {
             CompletionItem::new(CompletionKind::Reference, name.to_string())
-                .from_resolution(ctx.db, res)
+                .from_resolution(ctx, res)
                 .add_to(acc)
         });
     Ok(())
diff --git a/crates/ra_analysis/src/completion/completion_context.rs b/crates/ra_analysis/src/completion/completion_context.rs
index 71bf7fd32..949b8135e 100644
--- a/crates/ra_analysis/src/completion/completion_context.rs
+++ b/crates/ra_analysis/src/completion/completion_context.rs
@@ -24,6 +24,7 @@ pub(super) struct CompletionContext<'a> {
     pub(super) module: Option<hir::Module>,
     pub(super) function: Option<hir::Function>,
     pub(super) function_syntax: Option<ast::FnDef<'a>>,
+    pub(super) use_item_syntax: Option<ast::UseItem<'a>>,
     pub(super) is_param: bool,
     /// A single-indent path, like `foo`.
     pub(super) is_trivial_path: bool,
@@ -55,6 +56,7 @@ impl<'a> CompletionContext<'a> {
             module,
             function: None,
             function_syntax: None,
+            use_item_syntax: None,
             is_param: false,
             is_trivial_path: false,
             path_prefix: None,
@@ -114,6 +116,8 @@ impl<'a> CompletionContext<'a> {
             _ => (),
         }
 
+        self.use_item_syntax = self.leaf.ancestors().find_map(ast::UseItem::cast);
+
         self.function_syntax = self
             .leaf
             .ancestors()
diff --git a/crates/ra_analysis/src/completion/completion_item.rs b/crates/ra_analysis/src/completion/completion_item.rs
index b8fa39ae3..cd4d529f9 100644
--- a/crates/ra_analysis/src/completion/completion_item.rs
+++ b/crates/ra_analysis/src/completion/completion_item.rs
@@ -1,7 +1,7 @@
-use crate::db;
-
 use hir::PerNs;
 
+use crate::completion::CompletionContext;
+
 /// `CompletionItem` describes a single completion variant in the editor pop-up.
 /// It is basically a POD with various properties. To construct a
 /// `CompletionItem`, use `new` method and the `Builder` struct.
@@ -118,12 +118,12 @@ impl Builder {
         self.kind = Some(kind);
         self
     }
-    pub(crate) fn from_resolution(
+    pub(super) fn from_resolution(
         mut self,
-        db: &db::RootDatabase,
+        ctx: &CompletionContext,
         resolution: &hir::Resolution,
     ) -> Builder {
-        let resolved = resolution.def_id.and_then(|d| d.resolve(db).ok());
+        let resolved = resolution.def_id.and_then(|d| d.resolve(ctx.db).ok());
         let kind = match resolved {
             PerNs {
                 types: Some(hir::Def::Module(..)),
@@ -140,21 +140,27 @@ impl Builder {
             PerNs {
                 values: Some(hir::Def::Function(function)),
                 ..
-            } => {
-                if let Some(sig_info) = function.signature_info(db) {
-                    if sig_info.params.is_empty() {
-                        self.snippet = Some(format!("{}()$0", self.label));
-                    } else {
-                        self.snippet = Some(format!("{}($0)", self.label));
-                    }
-                }
-                CompletionItemKind::Function
-            }
+            } => return self.from_function(ctx, function),
             _ => return self,
         };
         self.kind = Some(kind);
         self
     }
+
+    fn from_function(mut self, ctx: &CompletionContext, function: hir::Function) -> Builder {
+        // If not an import, add parenthesis automatically.
+        if ctx.use_item_syntax.is_none() {
+            if let Some(sig_info) = function.signature_info(ctx.db) {
+                if sig_info.params.is_empty() {
+                    self.snippet = Some(format!("{}()$0", self.label));
+                } else {
+                    self.snippet = Some(format!("{}($0)", self.label));
+                }
+            }
+        }
+        self.kind = Some(CompletionItemKind::Function);
+        self
+    }
 }
 
 impl Into<CompletionItem> for Builder {