Allow positional args to be given non-positionally? about invoke HOT 4 CLOSED

OK, found one reason for the current setup, dealing with ambiguity between otherwise valid flag-like things and positional args, e.g. if for some reason you wanted a positional arg to get the value --foo (and where --foo is also a valid flag in the same context).

However I'm unconvinced this is really a good idea so I'll try changing it.

from invoke.

Tried updating some tests to take this change into account (re: no longer requiring positionals=[]), but they aren't working quite right. Still poking.

from invoke.

So, beforehand, @task(positional=[]) meant none of the args got set positional. I'm trying to undo those and just set them to @task. Currently, this means anything with no default value becomes available as positional (but -- due to this ticket -- still works fine as a flag. win-win.)

Somehow, being positional means flags no longer get picked up as auto_shortflags. E.g.:

@task
def foo(bar, b):
    pass

bar does not get set to -a (which is what it would get set to as a shortflag because -b is already taken). I assume, but have not tested, that foo(an_arg, b) would similarly NOT alias an_arg to -a.

This needs to be fixed as many tasks assume auto_shortflags works.

from invoke.

Finally untangled things:

• Shortflags were not getting made for positionals because there was still a "don't do this for positional args" test in the shortflags block. Oops.
• When that was fixed, shortflags no longer got set the way tests expected, because positionals get sent to the front of the list before shortflags get created (and thus take precedence).
• When that was fixed, other tests ensuring that when positional args are in fact given positionally and not as flags, the order matches what was given in @task(positional=[x, y, z]), failed, because positional order was lost.
• Finally, decided to preserve that ordering (which has to be communicated from Task to Context) by preserving the "make sure positionals come first" logic but applying it after creation of Argument objects and thus shortflags.

This has gotten all tests passing, though I am still with doubts about the overall positional API. E.g. I had to add @task(positionals=[]) to one test to ensure that one of the args with no default value still didn't get taken as a positional -- because positionals are still required if not given as a flag. It just feels kind of messy and easy to find pitfalls in.

Also, "I have an empty list for positionals" may be a correct or easy way of turning auto-positionals off for a given task, but it is also ugly. Make sure that if that doesn't fall under the purview of other issues, one is made.

from invoke.