OCaml 5.0 -> 5.1+: functions with explicit type signatures no longer show up in code lens and symbol list

[edwintorok]

Open the following file with an editor that is connected to OCaml LSP 1.17.0, and notice that some functions are missing a code lens, or are missing from the symbol list

(run a dune clean before, just in case):

type style = [ `Bold | `Italic | `Emphasis | `Superscript | `Subscript ]

let string_of_style : style -> string  = function
  | `Bold -> "bold"
  | `Italic -> "italic"
  | `Emphasis -> "emphasis"
  | `Superscript -> "superscript"
  | `Subscript -> "subscript"

let string_of_style2  = function
  | `Bold -> "bold"
  | `Italic -> "italic"
  | `Emphasis -> "emphasis"
  | `Superscript -> "superscript"
  | `Subscript -> "subscript"

Results:

(space s: list symbols)

• Helix + OCaml 4.14.1: string_of_style2, string_of_style, style
• Helix + OCaml 5.0: string_of_style2, string_of_style, style
• Helix +OCaml 5.1.1: string_of_style2, style
• Helix + OCaml 5.2.0-rc1 + ocaml-lsp 1.18.0~5.2preview: string_of_style2, style

Outline (VSCodium), select a different sandbox every time:

• 5.0.0: style, string_of_style, string_of_style2
• 5.1.1: style, string_of_style2

Enable all LSP features (Code lens, etc):

• 5.0.0:
• 5.1.1:

This seems to indicate that the problem is some change between OCaml 5.0.0 and 5.1.1, the LSP server is the same.

I can understand hiding the code lens (the type annotation is already there), but there is no reason to remove it from the global symbols list, that is a bug.
Also even if it might desirable to hide the code lens when explicit type annotations are available, that behaviour should be consistent across compiler versions.