[GROOVY-10561] @NamedVariant self referential default values are not correctly resolved

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.5.16, 3.0.10, 4.0.1
• Fix Version/s: 4.0.2
• Labels: named-parameters
• Assignee: Paul King
• Reporter: Leonard Brünings
• Created: 30/Mar/22 12:26
• Updated: 26/Feb/24 18:37
• Resolved: 15/Apr/22 14:10

Description

If a default parameter refers to another parameter ( String language = 'java', String extension = language ) it will fail, when the named variant is used.

import groovy.transform.NamedVariant
import spock.lang.Specification

class Demo {
    @NamedVariant
    String fileInSourceSet(String language = 'java', String extension = language) {
        return "$language -> .$extension"
    }
    
    def test() {
		assert fileInSourceSet() == 'java -> .java'
		assert fileInSourceSet('groovy') == 'groovy -> .groovy'
		assert fileInSourceSet(language: 'kotlin', extension: 'kt') == 'kotlin -> .kt'
        // fails
		assert fileInSourceSet(language: 'groovy') == 'groovy -> .groovy'
    }
    
    static main(args) {
            new Demo().test() 
    }    
}

See on WebConsole (as long as deployed version is 3.0.10)

groovy.lang.MissingPropertyException: No such property: language for class: Demo
	at Demo.fileInSourceSet(Script1.groovy)
	at Demo$fileInSourceSet$2.callCurrent(Unknown Source)
	at Demo.test(Script1.groovy:14)
	at Demo$test.call(Unknown Source)
	at Demo.main(Script1.groovy:18)

It generates

@groovy.transform.Generated
    public java.lang.String fileInSourceSet(@groovy.transform.NamedParams(value = [@groovy.transform.NamedParam(value = 'language', type = java.lang.String, required = false), @groovy.transform.NamedParam(value = 'extension', type = java.lang.String, required = false)]) java.util.Map namedArgs) {
        if ( namedArgs == null) {
            throw new java.lang.IllegalArgumentException('Named parameter map cannot be null')
        }
        for (java.lang.String namedArgKey : namedArgs.keySet()) {
            assert ['language', 'extension'].contains( namedArgKey ) : 'Unrecognized namedArgKey: ' + namedArgKey }
        return this.fileInSourceSet(namedArgs.containsKey('language') ? namedArgs.language : 'java', namedArgs.containsKey('extension') ? namedArgs.extension : language )
    }

The problematic line is namedArgs.containsKey('extension') ? namedArgs.extension : language which either would have to duplicate the logic for {{language}} or use a local variable for it.

Relates to GROOVY-10261

Issue Links

• relates to: GROOVY-11325 @NamedVariant self referential default values are not correctly resolved when calculations are involved
• relates to: GROOVY-10889 Casting of arguments in @NamedVariant method has no effect