Groovy JSON parsing with readable error messages

import groovy.json.JsonSlurper
import groovy.json.JsonException

def parseJson(String text) {
    if (text == null || text.trim().isEmpty()) {
        throw new IllegalArgumentException('JSON input is empty')
    }
    try {
        return new JsonSlurper().parseText(text)
    } catch (JsonException e) {
        throw new IllegalArgumentException("invalid JSON: ${e.message}", e)
    }
}

println parseJson('{"a": 1}').a
try {
    parseJson('{"a": }')
} catch (IllegalArgumentException e) {
    println "rejected: ${e.message.readLines().first()}"
}