[GROOVY-9599] CliBuilder: Option with "type: String, defaultValue ''" (empty String) results in NullObject if default value is applied

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.5.11, 3.0.4
• Fix Version/s: 3.0.5, 2.5.13
• Component/s: command line processing
• Assignee: Remko Popma
• Reporter: Remko Popma
• Created: 18/Jun/20 21:57
• Updated: 23/Jul/20 14:16
• Resolved: 22/Jun/20 01:27

Description

This is a follow-up ticket for GROOVY-9519:

After checking with Groovy 3.0.4, it seems that only the "Integer with defaultValue '0'" case was fixed, but not "String with defaultValue ''". The latter became even worse. It still ignores the defaultValue, but instead of creating a Boolean, it now creates a NullObject. Try this code:

@Grab('info.picocli:picocli-groovy:4.3.2')
@GrabConfig(systemClassLoader=true)

import groovy.cli.picocli.CliBuilder

def cli = new CliBuilder(name: 'cliTest.groovy', stopAtNonOption: false)
cli.h(type: Boolean, longOpt: 'help', usageHelp: true, required: false, 'Show usage information')
cli.a(type: String, longOpt: 'optA', required: false, args: 1, defaultValue: '', 'Option a (optional)')
def opts = cli.parse(args)
opts || System.exit(1)
if(opts.h) {
  cli.usage()
  System.exit(0)
}

println(opts.a.getClass())
if (opts.a) {
  println(opts.a)
}

with Groovy 3.0.2:

% ~/tmp/groovy-3.0.2/bin/groovy ./cliTest.groovy
class java.lang.Boolean

and with Groovy 3.0.4:

% ~/tmp/groovy-3.0.4/bin/groovy ./cliTest.groovy
class org.codehaus.groovy.runtime.NullObject

Issue Links

• is related to: GROOVY-9519 CLIBuilder: Option with "type: Integer, defaultValue '0'" results in Boolean if default value is applied