scatter-wf2.cwl

#!/usr/bin/env cwl-runner
cwlVersion: v1.0
class: Workflow

inputs:
  inp1: string[]
  inp2: string[]

outputs:
  out:
    outputSource: step1/echo_out
    type:
      type: array
      items:
        type: array
        items: string

requirements:
  - class: ScatterFeatureRequirement

steps:
  step1:
    in:
      echo_in1: inp1
      echo_in2: inp2
    out: [echo_out]

    scatter: [echo_in1, echo_in2]
    scatterMethod: nested_crossproduct
    run:
      class: CommandLineTool
      id: step1command
      inputs:
        echo_in1:
          type: string
          inputBinding: {}
        echo_in2:
          type: string
          inputBinding: {}
      outputs:
        echo_out:
          type: string
          outputBinding:
            glob: "step1_out"
            loadContents: true
            outputEval: $(self[0].contents)
      baseCommand: "echo"
      arguments:
        - "-n"
        - "foo"
      stdout: step1_out