hover function return remove nil

Author: xuhuanzy

crates/emmylua_ls/src/handlers/hover/hover_humanize.rs

@@ -351,7 +351,7 @@ fn build_signature_rets(
             overload_rets_string
         } else {
             let rets = &signature.return_docs;
-            if rets.is_empty() {
+            if rets.is_empty() || signature.get_return_type().is_nil() {
                 "".to_string()
             } else {
                 format!(
@@ -372,7 +372,7 @@ fn build_signature_rets(
         overload_rets_string
     } else {
         let rets = &signature.return_docs;
-        if rets.is_empty() {
+        if rets.is_empty() || signature.get_return_type().is_nil() {
             "".to_string()
         } else {
             let mut rets_string_multiline = String::new();

crates/emmylua_ls/src/handlers/hover/test/hover_function_test.rs

@@ -163,4 +163,23 @@ mod tests {
             },
         ));
     }
+
+    #[test]
+    fn test_4() {
+        let mut ws = ProviderVirtualWorkspace::new();
+        assert!(ws.check_hover(
+            r#"
+                ---@class ClosureTest
+                ---@field e fun(a: string, b: number)
+                local Test
+
+                function Test.<??>e(a, b)
+                    A = a
+                end
+            "#,
+            VirtualHoverResult {
+                value: "\n```lua\nfunction ClosureTest.e(a: string, b: number)\n```\n\n---\n\n---\n\n```lua\n(field) ClosureTest.e(a: string, b: number)\n```\n".to_string(),
+            },
+        ));
+    }
 }