3 files changed, 53 insertions, 10 deletions

diff --git a/crates/completion/src/render/const_.rs b/crates/completion/src/render/const_.rs
new file mode 100644
index 000000000..d88bfa07f
--- /dev/null
+++ b/crates/completion/src/render/const_.rs
@@ -0,0 +1,47 @@
+use hir::HasSource;
+use syntax::{
+    ast::{Const, NameOwner},
+    display::const_label,
+};
+
+use crate::{
+    item::{CompletionItem, CompletionItemKind, CompletionKind},
+    render::RenderContext,
+};
+
+#[derive(Debug)]
+pub(crate) struct ConstRender<'a> {
+    ctx: RenderContext<'a>,
+    const_: hir::Const,
+    ast_node: Const,
+}
+
+impl<'a> ConstRender<'a> {
+    pub(crate) fn new(ctx: RenderContext<'a>, const_: hir::Const) -> ConstRender<'a> {
+        let ast_node = const_.source(ctx.db()).value;
+        ConstRender { ctx, const_, ast_node }
+    }
+
+    pub(crate) fn render(self) -> Option<CompletionItem> {
+        let name = self.name()?;
+        let detail = self.detail();
+
+        let item = CompletionItem::new(CompletionKind::Reference, self.ctx.source_range(), name)
+            .kind(CompletionItemKind::Const)
+            .set_documentation(self.ctx.docs(self.const_))
+            .set_deprecated(self.ctx.is_deprecated(self.const_))
+            .detail(detail)
+            .build();
+
+        Some(item)
+    }
+
+    fn name(&self) -> Option<String> {
+        let ast_node = self.const_.source(self.ctx.db()).value;
+        ast_node.name().map(|name| name.text().to_string())
+    }
+
+    fn detail(&self) -> String {
+        const_label(&self.ast_node)
+    }
+}
diff --git a/crates/completion/src/render/function.rs b/crates/completion/src/render/function.rs
index 16f15e22c..d22081236 100644
--- a/crates/completion/src/render/function.rs
+++ b/crates/completion/src/render/function.rs
@@ -1,4 +1,4 @@
-use hir::{Documentation, HasAttrs, HasSource, Type};
+use hir::{HasSource, Type};
 use syntax::{ast::Fn, display::function_declaration};
 
 use crate::{
@@ -30,7 +30,7 @@ impl<'a> FunctionRender<'a> {
         let params = self.params();
         CompletionItem::new(CompletionKind::Reference, self.ctx.source_range(), self.name.clone())
             .kind(self.kind())
-            .set_documentation(self.docs())
+            .set_documentation(self.ctx.docs(self.fn_))
             .set_deprecated(self.ctx.is_deprecated(self.fn_))
             .detail(self.detail())
             .add_call_parens(self.ctx.completion, self.name, params)
@@ -45,8 +45,8 @@ impl<'a> FunctionRender<'a> {
         if let Some(derefed_ty) = ty.remove_ref() {
             for (name, local) in self.ctx.completion.locals.iter() {
                 if name == arg && local.ty(self.ctx.db()) == derefed_ty {
-                    return (if ty.is_mutable_reference() { "&mut " } else { "&" }).to_string()
-                        + &arg.to_string();
+                    let mutability = if ty.is_mutable_reference() { "&mut " } else { "&" };
+                    return format!("{}{}", mutability, arg);
                 }
             }
         }
@@ -80,8 +80,4 @@ impl<'a> FunctionRender<'a> {
             CompletionItemKind::Function
         }
     }
-
-    fn docs(&self) -> Option<Documentation> {
-        self.fn_.docs(self.ctx.db())
-    }
 }
diff --git a/crates/completion/src/render/macro_.rs b/crates/completion/src/render/macro_.rs
index bcf94f47e..0ad8c03b3 100644
--- a/crates/completion/src/render/macro_.rs
+++ b/crates/completion/src/render/macro_.rs
@@ -1,4 +1,4 @@
-use hir::{Documentation, HasAttrs, HasSource};
+use hir::{Documentation, HasSource};
 use syntax::display::macro_label;
 use test_utils::mark;
 
@@ -23,7 +23,7 @@ impl<'a> MacroRender<'a> {
         name: String,
         macro_: hir::MacroDef,
     ) -> MacroRender<'a> {
-        let docs = macro_.docs(ctx.db());
+        let docs = ctx.docs(macro_);
         let docs_str = docs.as_ref().map_or("", |s| s.as_str());
         let (bra, ket) = guess_macro_braces(&name, docs_str);