my first Geb (for HelloSample)

HelloSampleGeb

@Grab("org.codehaus.geb:geb-core:latest.release")
@Grab("org.seleniumhq.selenium:selenium-firefox-driver:latest.release")

import geb.*

class HelloPage extends Page {
    static url = 'http://localhost:8080/HelloSample/'
    static at = {title == 'Hello'}
    static content = {
        nameInput {
            $("input", name:"form1:name") 
        }
        greetingButton (to:GreetingPage){
            $("input", value:"greet")
        }
    }
}
class GreetingPage extends Page {
    static at = {title == "Greeting"}
    static content = {
        h1Text {$('h1').text()}
    }
}

Configuration conf = new Configuration()
//conf.setDriverConf('firefox')
//conf.setReportsDir(new File('Users/tomo'))

Browser.drive(){
    to HelloPage
    assert at(HelloPage)
//    nameInput = "JGGUG"   // ★２この記述では値が設定されない
    nameInput.value("JGGUG")   // ★２コメントで指摘していただいた方法で値設定
    
//    report 'hello_page'
    
    greetingButton.click()
    assert at(GreetingPage)
    
//    report 'Greeting_page'
    
    assert h1Text == 'Hello JGGUG'  // ★３テスト成功！
}