Having following in recipe.yaml:

tests:
  - requirements:
      run:
        - bzip2
    script:
      - if: unix
        then: 
          - test -f ${PREFIX}/fonts/Inconsolata-Regular.ttf
          - test -f ${PREFIX}/fonts/Inconsolata-Bold.ttf

will throw an error on windows: help: expected field ``script`` to be a list of commands
until you add - echo 'hello'.

I think we need treat if:then as a list in this case or treat it as an empty list