formats.keyValue: add tests

    '';

  };

  testKeyValueAtoms = {

    drv = evalFormat formats.keyValue {} {

      bool = true;

      int = 10;

      float = 3.141;

      str = "string";

    };

    expected = ''

      bool=true

      float=3.141000

      int=10

      str=string

    '';

  };

  testKeyValueDuplicateKeys = {

    drv = evalFormat formats.keyValue { listsAsDuplicateKeys = true; } {

      bar = [ null true "test" 1.2 10 ];

      baz = false;

      qux = "qux";

    };

    expected = ''

      bar=null

      bar=true

      bar=test

      bar=1.200000

      bar=10

      baz=false

      qux=qux

    '';

  };

  testKeyValueListToValue = {

    drv = evalFormat formats.keyValue { listToValue = concatMapStringsSep ", " (generators.mkValueStringDefault {}); } {

      bar = [ null true "test" 1.2 10 ];

      baz = false;

      qux = "qux";

    };

    expected = ''

      bar=null, true, test, 1.200000, 10

      baz=false

      qux=qux

    '';

  };

  testTomlAtoms = {

    drv = evalFormat formats.toml {} {

      false = false;