prometheus-nats-exporter: add updateScript and testVersion

{ lib, buildGoModule, fetchFromGitHub }:

{ lib, buildGoModule, fetchFromGitHub, gitUpdater, testers, prometheus-nats-exporter }:

buildGoModule rec {

  pname = "prometheus-nats-exporter";

    export GODEBUG=x509sha1=1;

  '';

  ldflags = [

    "-s"

    "-w"

    "-X main.version=${version}"

  ];

  passthru = {

    updateScript = gitUpdater { rev-prefix = "v"; };

    tests = {

      prometheus-nats-exporter-version = testers.testVersion {

        package = prometheus-nats-exporter;

      };

    };

  };

  meta = with lib; {

    description = "Exporter for NATS metrics";

    homepage = "https://github.com/nats-io/prometheus-nats-exporter";