expression-debuger.groovy

def model = [model:[book:[title:"The Shinning"]]]

def magicMethod= { String exp ->
	def out = [:]
	out.result = Eval.x(model,"x.with{${exp}}")
	try{
		if(out.result){
			Eval.x(model,"x.with{assert !(${exp})}")
		}else{
			Eval.x(model,"x.with{assert ${exp}}")
		}
	}catch(org.codehaus.groovy.runtime.powerassert.PowerAssertionError e){
		//out.detail = e.getMessage()
		def extra =""
		if(e.getMessage().contains("!(")){
			extra = "!("
			out.detail = e.getMessage().split("\n")[0..-2]
		}else{
			out.detail = e.getMessage().split("\n")
		}
		out.detail = out.detail.collect({ it.substring("       ${extra}".length()) }).join("\n")
	}
	return out
}


def expression = "model.book.title == \"The Shinning\""
def output = magicMethod(expression)

println "result: ${output.result}"
println "detail:\n${output.detail}"



expression = "model.book.title == \"what ever\""
output = magicMethod(expression)

println "result: ${output.result}"
println "detail:\n${output.detail}"