{
  lib,
  pkgs,
  ntlib,
  ...
}: {
  suites."Lib Tests".tests = [
    {
      name = "autodiscovery";
      type = "script";
      script = let
        actual = builtins.toFile "actual" (builtins.toJSON (ntlib.autodiscover {
          dir = ./fixtures;
        }));
      in
        # sh
        ''
          ${ntlib.helpers.path [pkgs.gnugrep]}
          ${ntlib.helpers.scriptHelpers}
          assert_file_contains ${actual} "sample_test.nix" "should find sample_test.nix"
          assert_file_contains ${actual} "\"base\":\"/nix/store/.*-source/tests/fixtures" "should set base to fixtures dir"
        '';
    }
    {
      name = "binary";
      type = "script";
      script = let
        binary =
          (ntlib.mkBinary {
            nixtests = "stub";
            extraParams = "--pure";
          })
          + "/bin/nixtests:run";
      in
        # sh
        ''
          ${ntlib.helpers.path [pkgs.gnugrep]}
          ${ntlib.helpers.scriptHelpers}
          assert_file_contains ${binary} "nixtest" "should contain nixtest"
          assert_file_contains ${binary} "--pure" "should contain --pure arg"
          assert_file_contains ${binary} "--tests=stub" "should contain --tests arg"

          run "${binary} --help"
          assert_eq $exit_code 0 "should exit 0"
          assert_contains "$output" "Usage of nixtest" "should show help"

          run "${binary}"
          assert_eq $exit_code 1 "should exit 1"
          assert_contains "$output" "Tests file does not exist"
        '';
    }
    {
      name = "full run with fixtures";
      type = "script";
      script = let
        binary =
          (ntlib.mkNixtest {
            modules = ntlib.autodiscover {dir = ./fixtures;};
            args = {inherit pkgs;};
          })
          + "/bin/nixtests:run";
      in
        # sh
        ''
          ${ntlib.helpers.path [pkgs.gnugrep pkgs.mktemp]}
          ${ntlib.helpers.scriptHelpers}

          TMPDIR=$(tmpdir)
          run "${binary} --pure --junit=$TMPDIR/junit.xml"
          assert "$exit_code -eq 2" "should exit 2"
          assert "-f $TMPDIR/junit.xml" "should create junit.xml"
          assert_contains "$output" "executable file not found" "nix should not be found in pure mode"

          ${ntlib.helpers.pathAdd [pkgs.nix pkgs.coreutils]}
          run "${binary} --pure --junit=$TMPDIR/junit2.xml"
          assert "$exit_code -eq 2" "should exit 2"
          assert "-f $TMPDIR/junit2.xml" "should create junit2.xml"
          assert_not_contains "$output" "executable file not found" "nix should now exist"
          assert_contains "$output" "suite-one" "should contain suite-one"
          assert_contains "$output" "8/11 (1 SKIPPED)" "should be 8/11 total"
          assert_contains "$output" "ERROR" "should contain an error"
          assert_contains "$output" "SKIP" "should contain a skip"
        '';
    }
  ];
}