nixpkgs/nixos/tests/mailpit.nix

import ./make-test-python.nix (
  { lib, ... }:
  {
    name = "mailpit";
    meta.maintainers = lib.teams.flyingcircus.members;

    nodes.machine =
      { pkgs, ... }:
      {
        services.mailpit.instances.default = { };

        environment.systemPackages = with pkgs; [ swaks ];
      };

    testScript = ''
      start_all()

      from json import loads

      machine.wait_for_unit("mailpit-default.service")
      machine.wait_for_open_port(1025)
      machine.wait_for_open_port(8025)
      machine.succeed(
          'echo "this is the body of the email" | swaks --to root@example.org --body - --server localhost:1025'
      )

      received = loads(machine.succeed("curl http://localhost:8025/api/v1/messages"))
      assert received['total'] == 1
      message = received["messages"][0]
      assert len(message['To']) == 1
      assert message['To'][0]['Address'] == 'root@example.org'
      assert "this is the body of the email" in message['Snippet']
    '';
  }
)