rough, but appears to work

crates/ide/src/hover/render.rs

@@ -411,6 +411,7 @@ where
     D: HasAttrs + HirDisplay,
 {
     let label = def.display(db).to_string();
+    println!("label: {label:?}");
     let docs = def.attrs(db).docs();
     (label, docs)
 }

crates/ide/src/hover/tests.rs

@@ -1310,6 +1310,42 @@ fn test_hover_function_show_qualifiers() {
     );
 }
 
+#[test]
+fn test_hover_function_show_types() {
+    check(
+        r#"fn foo$0(a: i32, b:i32) -> i32 { 0 }"#,
+        expect![[r#"
+                *foo*
+
+                ```rust
+                test
+                ```
+
+                ```rust
+                fn foo(a: i32, b: i32) -> i32
+                ```
+            "#]],
+    );
+}
+
+#[test]
+fn test_hover_function_pointer_show_types() {
+    check(
+        r#"type foo$0 = fn(a: i32, b: i32) -> i32;"#,
+        expect![[r#"
+                *foo*
+
+                ```rust
+                test
+                ```
+
+                ```rust
+                type foo = fn(a: i32, b: i32) -> i32
+                ```
+            "#]],
+    );
+}
+
 #[test]
 fn test_hover_trait_show_qualifiers() {
     check_actions(