Fix hover on method calls

CHANGES.md

@@ -1,3 +1,9 @@
+# unreleased
+
+## Fixes
+
+- Fix hover on method calls not showing the type. (#1553, fixes #1552)
+
 # 1.23.0
 
 ## Features

ocaml-lsp-server/src/hover_req.ml

@@ -58,8 +58,10 @@ let hover_at_cursor parsetree (`Logical (cursor_line, cursor_col)) =
     then (
       match expr.pexp_desc with
       | Pexp_constant _ | Pexp_variant _ | Pexp_pack _ -> result := Some `Type_enclosing
-      | Pexp_ident { loc; _ } | Pexp_construct ({ loc; _ }, _) | Pexp_field (_, { loc; _ })
-        ->
+      | Pexp_ident { loc; _ }
+      | Pexp_construct ({ loc; _ }, _)
+      | Pexp_field (_, { loc; _ })
+      | Pexp_send (_, { loc; _ }) ->
         if is_at_cursor loc
         then result := Some `Type_enclosing
         else Ast_iterator.default_iterator.expr self expr

ocaml-lsp-server/test/e2e-new/dune

@@ -51,6 +51,7 @@
     document_flow
     exit_notification
     for_ppx
+    hover
     hover_extended
     inlay_hints
     jump_to_typed_hole

ocaml-lsp-server/test/e2e-new/hover.ml

@@ -0,0 +1,43 @@
+open Test.Import
+
+let print_hover hover =
+  match hover with
+  | None -> print_endline "no hover response"
+  | Some hover ->
+    hover |> Hover.yojson_of_t |> Yojson.Safe.pretty_to_string ~std:false |> print_endline
+;;
+
+let hover client position =
+  Client.request
+    client
+    (TextDocumentHover
+       { HoverParams.position
+       ; textDocument = TextDocumentIdentifier.create ~uri:Helpers.uri
+       ; workDoneToken = None
+       })
+;;
+
+let%expect_test "object method call" =
+  let source =
+    {ocaml|
+let f (o : <  g : int -> unit >) = o#g 4
+|ocaml}
+  in
+  let position = Position.create ~line:1 ~character:38 in
+  let req client =
+    let* resp = hover client position in
+    let () = print_hover resp in
+    Fiber.return ()
+  in
+  Helpers.test source req;
+  [%expect
+    {|
+    {
+      "contents": { "kind": "plaintext", "value": "int -> unit" },
+      "range": {
+        "end": { "character": 38, "line": 1 },
+        "start": { "character": 35, "line": 1 }
+      }
+    }
+    |}]
+;;