{ lib, formats, stdenvNoCC, writeText, ... }:
let
  hocon = formats.hocon { };

  include_file = (writeText "hocon-test-include.conf" ''
    "val" = 1
  '').overrideAttrs (_: _: {
    outputHashAlgo = "sha256";
    outputHashMode = "flat";
    outputHash = "sha256-UhkJLhT3bD6znq+IdDjs/ahP19mLzrLCy/R14pVrfew=";
  });

  expression = {
    simple_top_level_attr = "1.0";
    nested.attrset.has.a.integer.value = 100;
    some_floaty = 29.95;

    array2d = [
      [ 1 2 "a" ]
      [ 2 1 "b" ]
    ];
    nasty_string = "\"@\n\\\t^*\b\f\n\0\";'''$";

    "misc attrs" = {
      x = 1;
      y = hocon.lib.mkAppend { a = 1; };
    };

    "cursed \" .attrs \" " = {
      "a" = 1;
      "a b" = hocon.lib.mkSubstitution "a";
      "a b c" = hocon.lib.mkSubstitution {
        value = "a b";
        required = false;
      };
    };

    to_include = {
      _includes = [
        (hocon.lib.mkInclude include_file)
        (hocon.lib.mkInclude "https://example.com")
        (hocon.lib.mkInclude {
          required = true;
          type = "file";
          value = include_file;
        })
        (hocon.lib.mkInclude { value = include_file; })
        (hocon.lib.mkInclude {
          value = "https://example.com";
          type = "url";
        })
      ];
    };
  };

  hocon-test-conf = hocon.generate "hocon-test.conf" expression;
in
  stdenvNoCC.mkDerivation {
    name = "pkgs.formats.hocon-test-comprehensive";

    dontUnpack = true;
    dontBuild = true;

    doCheck = true;
    checkPhase = ''
      runHook preCheck

      diff -U3 ${./expected.txt} ${hocon-test-conf}

      runHook postCheck
    '';

    installPhase = ''
      runHook preInstall

      mkdir $out
      cp ${./expected.txt} $out/expected.txt
      cp ${hocon-test-conf} $out/hocon-test.conf
      cp ${hocon-test-conf.passthru.json} $out/hocon-test.json

      runHook postInstall
    '';
  }
