Can Dyalog user commands be invoked from code?

My understanding is that generally one shouldn’t want to do this, but my particular use case involves testing a custom user command, so being able to invoke something like ⎕SE.Foo 'mycmd my arguments' would be quite useful.

>Solution :

Yes, per the documentation:

This implementation means that application code can invoke user commands by calling ⎕SE.UCMD directly.

In your case, it would be ⎕SE.UCMD 'mycmd my arguments'