Can not pass options to the script executed by ipython

[egilewski]

Unlike the default Flask shell, this one allows to specify a script to execute, just like outside of Flask do ipython script.py and python script.py. However passing options to a script invoked that way may require a preceding -- separator, which is being dropped by click library and never makes it to IPython.start_ipython(argv=ipython_args,

Demonstration:

$ echo 'import sys; print(sys.argv)' >script.py

Works as expected:

$ flask shell script.py --test test
[TerminalIPythonApp] WARNING | Unrecognized alias: 'test', it will have no effect.
['/usr/src/script.py']

Doesn't work as expected:

$ flask shell script.py -- --test test
[TerminalIPythonApp] WARNING | Unrecognized alias: 'test', it will have no effect.
['/usr/src/script.py']

Expected result in the second case:

$ flask shell script.py -- --test test
['/usr/src/script.py', '--test', 'test']

It seems that the required feature is missing in click, though may be added in pallets/click#2205 (see also pallets/click#619 and pallets/click#1340).

I realize that this may not have been a planned feature, but this would be a nice extra thing that the default Flask shell doesn't offer.

[egilewski]

I found a way, though it's a strange one: $ flask shell script.py -- -- --test test

[ei-grad]

To make it doesn't look strange, the proper syntax would be flask shell -- script.py -- --test test. For me it looks like it works as expected.

But I agree that -- handling by click is really not intuitive in the first example. A related issue exists in pallets/click#619.

Not sure if it could be a good idea to change this behavior.

[ei-grad]

Hmm. Looks like I got the issue wrong. First example actually is not related to pallets/click#619.

[ei-grad]

Works as expected:

$ flask shell script.py --test test
[TerminalIPythonApp] WARNING | Unrecognized alias: 'test', it will have no effect.
['/usr/src/script.py']

This actually doesn't work as expected (as of my sense), and it changed behavior in IPython 8.x (with IPython<8 it results in error and non-zero exit code instead of a WARNING log message). But still I don't think we should do anything with it, because passing options after the filename argument matches the ipython behavior to interpret this options as dedicated to ipython:

→ ipython script.py --test test
[TerminalIPythonApp] WARNING | Unrecognized alias: 'test', it will have no effect.
['/home/ei-grad/repos/github.com/ei-grad/flask-shell-ipython/script.py']

[ei-grad]

This actually doesn't work as expected (as of my sense)

Oh. Sorry, it looks like I got the message a little bit wrong again :-).

[ei-grad]

Not sure what to do with this :-). Probably we can just document it in the README. Any thoughts are welcome.

[egilewski]

Maybe it will be ripe for an easy solution after pallets/click#2205 is resolved.

README shouldn't hurt, but just the ability to find this issue with a strange/not strange solution should save people time.