nextflow-io/nextflow

Hi Paolo, hi all,
is there a way to execute groovy code within the Nextflow config file? I would like to generate a file that contains, for example, $workflow.projectDir and then assign the name of the file to a param variable. I tried the following but it didn't work

param.csvfile = { 
        file1 = new File('test.csv')
        file1.write $workflow.projectDir
        return "test.csv"
    }

I get the following error: ERROR ~ No signature of method: nextflow.config.ConfigParser$_parse_closure5.endsWith() is applicable for argument types: (java.lang.String) values: [csv]