Decode failure detection is incorrect in PestJSON

[arokettu]

• json_decode returns NULL not FALSE on decode failure
• NULL and FALSE are also returned for their valid json counterparts so we also need to check for errors (this also makes failure detection in php < 5.3 a challenge)

json_decode('null') // => null
json_decode('false') // => false

[arokettu]

For PHP 5.2 we can check by

strtolower(trim($body)) !== 'null'

but I don't think it's a hack suitable for a library

[djsipe]

Good find. Thanks!