Is there a way to convert ["null", File] to File in CWL?

Question

[Azat Badretdin]

Is there a way to convert ["null", File] to File in CWL?

I understand the typing risk.

[GenoMax]

Please use cwl tag with CWL questions. People who support CWL follow those. I have added that tag for you.

[Azat Badretdin]

That was my first inclination, yet for some weird reason I was not able to find that tag. Maybe I should try harder next time.

[GenoMax]

You just start typing the word. If a tag exists then it will show up otherwise you can create a new one by selecting the word you just typed.

[Michael R. Crusoe]

Hello azat1b, can you give us more context as to what you're trying to do?

Answer 1

[bogdan.gavrilovic]

Hi,
I think you have no reason for concern.
When an input/output type is defined as any list of types, e.g. [string, File] - it means that the item that appears on that input/output in execution is one of these possible types (unless input is a defined as [wave, particle], in that case it can be both at the same time if you use quantum computers.) .
In your case the representation ["null", File] means that this input/output is optional(can be a File or can be null depending on how you use it)