json_validate.php

<?php

if (! function_exists('json_validate')) {
    /**
     * Validate a json string.
     *
     * @param  string  $json
     * @param  boolean $throw
     * @return boolean
     * @throws \InvalidArgumentException
     */
    function json_validate($json, $throw = false)
    {
        $result = json_decode($json);
        $errorCode = json_last_error();
        $valid = $errorCode === JSON_ERROR_NONE;

        if ($valid === false && $throw) {
            $messages = [
                JSON_ERROR_DEPTH => 'The maximum stack depth has been exceeded.',
                JSON_ERROR_STATE_MISMATCH => 'Invalid or malformed JSON.',
                JSON_ERROR_CTRL_CHAR => 'Control character error, possibly incorrectly encoded.',
                JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON.',
                JSON_ERROR_UTF8 => 'Malformed UTF-8 characters, possibly incorrectly encoded.',
                JSON_ERROR_RECURSION => 'One or more recursive references in the value to be encoded.',
                JSON_ERROR_INF_OR_NAN => 'One or more NAN or INF values in the value to be encoded.',
                JSON_ERROR_UNSUPPORTED_TYPE => 'A value of a type that cannot be encoded was given.',
            ];

            throw new InvalidArgumentException(
                $messages[$errorCode] ?? 'Unknown JSON error occured.'
            );
        }

        return $valid;
    }
}