beam_js/test/beam_js_test.exs

defmodule BeamJsTest do
  use BeamJs.JsCase
  doctest BeamJs

  test "can run JS code", %{js: js} do
    assert run(js, "1") == {:ok, 1}
  end

  test "can encode and import", %{js: js} do
    js_src =
      Example
      |> BeamJs.Module.to_ast(only: ["fact$1"])
      |> BeamJs.Encoder.encode_module()

    File.write!("tmp/example.mjs", js_src)

    assert {:ok, [[_label, [["func_info", "Elixir.Example", "fact", 1]]]| _rest]} = run(js, ~s|const Example = await import('./tmp/example.mjs');JSON.stringify(Example.fact$1)|)
  end
end