jenkins pipeline: can't pass build parameters to shared library vars

Question

Basically I can't pass build properties to Library var call without extra nonsense.

jenkinsfile relevant chunk:

tc_test{
    repo = 'test1'
    folder = 'test2'
    submodules = true
    refs = params.GitCheckout
}

That results in error

java.lang.NullPointerException: Cannot get property 'GitCheckout' on null object

This, however, works:

def a1 = params.GitCheckout
tc_test{
    repo = 'test1'
    folder = 'test2'
    submodules = true
    refs = a1
}

The contents of the vars/tc_test.groovy in shared library :

def call ( body ) {

    def config = [:]
    body.resolveStrategy = Closure.DELEGATE_FIRST
    body.delegate = config
    try {
        body()
    } catch(e) {
        currentBuild.result = "FAILURE";
        throw e;
    } finally {

        config.each{ k, v -> println "${k}:${v}" }

    }
}

I'm not really good with groovy, so it might be something obvious.

Answer 1

Got the answer from Jenkins JIRA.

Small workaround is using maps instead of closures:

tc_test ([
  repo: 'test1',
  folder: 'test2',
  submodules: true,
  refs = params.GitCheckout
])

May have drawbacks, but for me that worked perfectly.

Still have to transfer params as argument to have access to them, but at least the code makes more sense now.