fix hover doc function

Author: xuhuanzy

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

@@ -259,14 +259,13 @@ fn hover_doc_function_type(
     } else {
         func_name.to_string()
     };
-
     let params = lua_func
         .get_params()
         .iter()
         .enumerate()
         .map(|(index, param)| {
             let name = param.0.clone();
-            if index == 0 && is_method {
+            if index == 0 && is_method && !lua_func.is_colon_define() {
                 "".to_string()
             } else if let Some(ty) = &param.1 {
                 format!("{}: {}", name, humanize_type(db, ty, RenderLevel::Normal))

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

@@ -394,4 +394,35 @@ mod tests {
             },
         ));
     }
+
+    #[test]
+    fn test_generic_function() {
+        let mut ws = ProviderVirtualWorkspace::new();
+        ws.def_file(
+            "test.lua",
+            r#"
+                    ---@class Observable<T>
+                    local Observable
+
+                    ---@generic R
+                    ---@param selector fun(value: T, index?: integer): R
+                    function Observable:select(selector)
+                    end
+
+                    ---@type Observable<integer>
+                    source = {}
+
+            "#,
+        );
+        assert!(ws.check_hover(
+            r#"
+                    source:sel<??>ect(function(value)
+                        return value
+                    end)
+            "#,
+            VirtualHoverResult {
+                value: "```lua\n(method) Observable:select(selector: fun(value: integer, index: integer?) -> R)\n```".to_string(),
+            },
+        ));
+    }
 }