use strict; use warnings;

package MyTypes {
    use parent 'Type::Library';
    use Type::Utils;
    use Types::Standard qw/ Dict Enum Str /;

    declare MyType => as Dict[
        method  => Enum['xxx'],
        backend => Dict[
            client => Str,
            pw     => Str,
        ],
    ];
};

package main {
    use JSON;

    MyTypes->import(qw/ +MyType /);

    my $data = from_json q|{
        "method": "xxx",
        "backend": {
            "client": "mytest009",
            "pw": "sdkjfhsfjhKJH87"
        },
        "blah": "123"
    }|;

    assert_MyType( $data );

};

__END__

##</code><code>##

Reference {"backend" => {"client" => "mytest009","pw" => "sdkjfhsfjhKJ...} did not pass type constraint "MyType" at 1209129-2.pl line 31
    "MyType" is a subtype of "Dict[backend=>Dict[client=>Str,pw=>Str],method=>Enum["xxx"]]"
    Reference {"backend" => {"client" => "mytest009","pw" => "sdkjfhsfjhKJ...} did not pass type constraint "Dict[backend=>Dict[client=>Str,pw=>Str],method=>Enum["xxx"]]"
    "Dict[backend=>Dict[client=>Str,pw=>Str],method=>Enum["xxx"]]" does not allow key "blah" to appear in hash