OCaml Dune project with unit tests

bin > dune

(executable
 (public_name helloworld)
 (name main)
 (libraries helloworld))

bin > main.ml

let () =
  if Array.length Sys.argv > 1 then
    print_endline (Helloworld.hello Sys.argv.(1))
  else
    print_endline Helloworld.hello_world

dune-project

(lang dune 3.17)

(name helloworld)

(generate_opam_files true)

(source
 (github username/reponame))

(authors "Author Name <[email protected]>")

(maintainers "Maintainer Name <[email protected]>")

(license LICENSE)

(documentation https://url/to/documentation)

(package
 (name helloworld)
 (synopsis "A short synopsis")
 (description "A longer description")
 (depends
  ocaml
  (alcotest :with-test))
 (tags
  ("add topics" "to describe" your project)))

; See the complete stanza docs at https://dune.readthedocs.io/en/stable/reference/dune-project/index.html

lib > dune

(library
 (name helloworld))

lib > helloworld.ml

let hello name =
  "Hello, " ^ name ^ "!"

let hello_world =
  hello "World"

test > dune

(test
 (name test_helloworld)
 (libraries alcotest helloworld))

test > test_helloworld.ml

open Helloworld

let test_hello_world () =
  Alcotest.(check string) "same string" "Hello, World!" (hello_world)

let test_hello_name () =
  Alcotest.(check string) "same string" "Hello, Jane!" (hello "Jane")

let () =
  let open Alcotest in
  run "Helloworld" [
      "hello_world", [ test_case "hello_world with default message" `Quick test_hello_world ];
      "hello", [ test_case "hello with given name" `Quick test_hello_name ];
    ]