[CLI-302] More user-friendly error handling for missing required arguments

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 1.4
• Component/s: CLI-1.x
• Assignee: Unassigned
• Reporter: rkrisztian
• Created: 17/Jan/20 08:54
• Updated: 17/Jan/20 08:54

Description

Currently when I specify a flag that requires an argument, but I actually don't specify that argument, I get the usage plus an exception. It would be nicer for the user if the exception did not happen:

$ myCliApp -a
error: Missing argument for option: a
usage: [options]
Options:
 -a,--argument <arg>   specify this argument
Exception in thread "main" java.lang.NullPointerException: Cannot invoke method hasOption() on null object
	at org.codehaus.groovy.runtime.NullObject.invokeMethod(NullObject.java:91)
	at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:47)
	at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47)
	at org.codehaus.groovy.runtime.callsite.NullCallSite.call(NullCallSite.java:34)
	at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:115)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:127)
	at groovy.cli.commons.CliBuilder.processSetAnnotation(CliBuilder.groovy:561)

And I cannot control this because I just call:

cli.parseFromInstance options, args

Thanks in advance.