this (mostly) works for me using typer.Argument('default', autocompletion=my_autocomplete) tho am running into a weird bug with pwsh/win11 vs bash/osx

@patricksurry autocompletion works, but it is deprecated in click

DeprecationWarning: 'autocompletion' is renamed to 'shell_complete'. The old name is deprecated and will be removed in Click 8.1. See the docs about 'Parameter' for information about new behavior.

I'm still unable to make Arguments work with shell_complete.

On the opposite, shell_complete works very well with Options.

This is the situation, at least for me:

which shell are you using with --install-completion? my problem turned out to be a bug with powershell completion

does that mean the typer docs are out of date? they don't seem to mention shell_completion. i wonder if the deprecation warning itself (via logging.warn) might actually mess things up since it could be generating spurious output in the completion execution path (e.g. when the _TYPER... env vars are set)?

I'm using bash (on Ubuntu 20.04). But I assume (maybe I'm wrong) that completion should work on the shell because it works with Options. In case of troubles at shell level I was expecting the completion to don't work at all

You are right about the docs, no mention of shell_complete.
shell_complete has been added with typer 0.4.0 to support click 8 (with this PR #317)

There is a test with typer.Option + shell_complete

But nothing with typer.Argument + shell_complete

The lack of documentation may suggest that the support is still not completed. I think that only @tiangolo can clarify

I experience exactly the same behaviour / error:
my env:
fish 3.3.1
typer: 0.4.1
click: 8.1.2

This issue seems to be fixed, at least when using Ubuntu 22.04, env:
typer: 0.9.0
click: 8.1.7

This is in fact a very simple bug. The shell_complete parameter is not passed to TyperArgument. See here.

I will submit a PR.

If anyone has the ability to switch this issue label to a bug that would be appreciated!

It might be a while before my PR is merged so, here's the most minimally invasive monkey patch I could come up with to fix this:

from typer import __version__

if (0, 4, 0) <= tuple(int(v) for v in __version__.split(".")) <= (0, 13, 0):
    from typer import main as typer_main
    from typer.models import ParamMeta

    upstream_get_click_param = typer_main.get_click_param

    def patched_get_click_param(
        param: ParamMeta,
    ) -> t.Tuple[t.Union[click.Argument, click.Option], t.Any]:
        """
        Patch this bug: https://github.com/tiangolo/typer/issues/334
        """
        click_param = upstream_get_click_param(param)
        if isinstance(click_param[0], click.Argument) and getattr(
            param.default, "shell_complete", None
        ):
            click_param[0]._custom_shell_complete = param.default.shell_complete
        return click_param

    typer_main.get_click_param = patched_get_click_param