[ { "description": "validation of host names", "schema": {"format": "hostname"}, "tests": [ { "description": "a valid host name", "data": "www.example.com", "valid": true }, { "description": "a valid punycoded IDN hostname", "data": "xn--4gbwdl.xn--wgbh1c", "valid": true }, { "description": "a host name starting with an illegal character", "data": "-a-host-name-that-starts-with--", "valid": false }, { "description": "a host name containing illegal characters", "data": "not_a_valid_host_name", "valid": false }, { "description": "a host name with a component too long", "data": "a-vvvvvvvvvvvvvvvveeeeeeeeeeeeeeeerrrrrrrrrrrrrrrryyyyyyyyyyyyyyyy-long-host-name-component", "valid": false } ] } ]