Expect tests without ppx

Windtrap is a no-ppx alternative for writing expect tests in OCaml. Tests use plain function calls — expect {|...|} — instead of ppx syntax.

Place @mdexp.snapshot before the expect call, and mdexp extracts the block string content, just as it does with [%expect].

Example

open Windtrap

let greet name = Printf.printf "Hello, %s!\n" name

Let’s add mdexp directives to a windtrap test:

  let () =
    let tests =
      [ test "greeting" (fun () ->
+         (* @mdexp When you greet the world, like so: *)
+         (* @mdexp.code *)
          greet "World";
+         (* @mdexp the following happens: *)
+         (* @mdexp.snapshot { lang: "text" } *)
          expect {|Hello, World!|})
      ]
    in
    (run "Windtrap Snapshots" tests [@coverage off])
  ;;

This would yield the following markdown:

When you greet the world, like so:

greet "World";

the following happens:

Hello, World!