Difficulty testing Sexp.Sexp_with_layout

Learning
1

We have the following function I want to test:


  let string__to__sexp_with_layout (s : string) : Sexp_with_layout.t_or_comment =
    let lexbuf = Lexing.from_string s in
    Sexp_with_layout.(Parser.sexp Lexer.main lexbuf)

  let%test_unit "string__to__sexp_with_layout" =
    [%test_eq: Sexp_with_layout.t_or_comment] (string__to__sexp_with_layout "23")
      ...

So basically I want to test the parser function on an input of “23” by writing out the literal Sexp.Sexp_with_layout.t_or_comment struct that we generate.

However, the problem I am running into is that compare is apparently not defined on this type. Is there a way to write this unit test ?

2

You can probably generate a comparison (or equal) function with the “eq” deriver in the standard set of ppx deriving plugins. You’ll need to supply your own function fun a b -> true for the equality function for the location type.