[FIXED] Jenkinsfile: How to call a groovy function with named arguments

Issue

I have a simple Declarative Pipeline with function inside. How to correctly use named arguments for a function?

def getInputParams(param1='a', param2='b') {
    echo "param1 is ${param1}, param2 is ${param2}"
}

pipeline {
...
...
    stages {
        stage('Test) {
            steps {
                getInputParams(param1='x', param2='y')
            }
        }
    }
}

I cannot understand why named params become null in function?

[Pipeline] echo
param1 is null, param2 is null
...

Well, I'm able to call function like getInputParams('x', 'y'), but it's not human readable (arguments amount may increase in future)

Solution

Groovy is executed inside the Jenkinsfile so you have to follow its syntax for named arguments.

foo(name: 'Michael', age: 24)
def foo(Map args) { "${args.name}: ${args.age}" }

---

Quote from Groovy's named arguments:

Like constructors, normal methods can also be called with named arguments. They need to receive the parameters as a map. In the method body, the values can be accessed as in normal maps (map.key).

def getInputParams(Map map) {
    echo "param1 is ${map.param1}, param2 is ${map.param2}"
}

pipeline {
...
    stages {
        stage('Test') {
            steps {
                getInputParams(param1: 'x', param2: 'y')
            }
        }
    }
}

Answered By - Michael Kemmerzell
Answer Checked By - Mary Flores (JavaFixing Volunteer)