{ pkgs, mkJekyllSite }:
let
  mkTest = name: content: test:
    let
      testDir = pkgs.runCommand "test-env-${name}" {} ''
        mkdir -p $out
        cat > $out/index.html <<EOF
        ${content}
        EOF
        cat > $out/_config.yml <<EOF
        exclude: []
        EOF
      '';

      site = mkJekyllSite {
        pname = "test-${name}";
        src = testDir;
        gemset = ./test-files/gemset.nix;
        gemfile = ./test-files/Gemfile;
        lockfile = ./test-files/Gemfile.lock;
      };
    in
    pkgs.runCommand "test-${name}" {} ''
      ${test site}
      touch $out
    '';

  tests = {
    basic = mkTest "basic" "<h1>Test Page</h1>" (site: ''
      test -f ${site}/index.html || (echo "Missing index.html" && exit 1)
      grep -q "<h1>Test Page</h1>" ${site}/index.html
    '');

    minification = mkTest "minify" "<div>  <h1>  Test  </h1>  </div>" (site: ''
      ! grep -q "  " ${site}/index.html || (echo "Not minified" && exit 1)
    '');
  };
in
{
  checks = tests;
  apps.test = {
    type = "app";
    program = "${pkgs.writeScriptBin "run-tests" ''
      #!${pkgs.bash}/bin/bash
      set -euo pipefail
      ${builtins.concatStringsSep "\n"
        (map (name: "echo Testing ${name}... && test -e ${tests.${name}}")
          (builtins.attrNames tests))}
      echo "All tests passed!"
    ''}/bin/run-tests";
  };
}