+testfileset('add unconditionally', "$/0$/", [undef() => '0'], 1, "$/0$/0$/");
+testfileset('add string', "foo$/", ['bar'], 1, "foo$/bar$/");
+testfileset('keep string', "foo$/bar$/", ['foo'], 0, "foo$/bar$/");
+testfileset('keep first', "foo$/FOO$/foo$/", ['foo'], 1, "foo$/FOO$/");
+testfileset('replace string', "$/0$/1$/2$/", [0 => 3], 2, "$/1$/2$/3$/");
+testfileset('keep regex', "foo$/hi$/$/", [qr/./ => 'hi'], 1, "hi$/$/");
+
+testfileset('add new array', ".$/", ['' => ['foo','.']], 2, ".$/foo$/.$/");
+testfileset('replace by array', "$/foo$/.$/", ['' => ['foo','']], 3, "foo$/.$/foo$/$/");
+testfileset('partial add', "foo$/$/", ['foo' => ['foo','.']], 1, "foo$/$/.$/");
+
+my $SAMPLE2 = "$/foo$/and$/bar$/.$/";
+testfileset('keep pair', $SAMPLE2, [['foo','bar']], 0, "$/foo$/and$/bar$/.$/");
+testfileset('keep order', $SAMPLE2, [['bar','foo']], 2, "$/and$/bar$/.$/foo$/");
+testfileset('replace pair', $SAMPLE2, [['bar','foo'] => ['fooo','barr']], 4, "$/and$/.$/fooo$/barr$/");
+testfileset('mixed arrays', $SAMPLE2, [['ignore',qr/a/] => ['bar','foo','.']], 3, "$/foo$/bar$/.$/foo$/.$/");
+
+is(remove_tree($target), 19, 'no unexpected files');