Add typer.Parameter for describing unknown parameters in the context_settings={"allow_extra_args": True, "ignore_unknown_options": True}

[jnareb]

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Example Code

import typer
from typing_extensions import Annotated

app = typer.Typer()


@app.command(
    context_settings={"allow_extra_args": True, "ignore_unknown_options": True}
)
def main(cmd: Annotated[
            str,
            typer.Argument(
                help="Command to invoke",
                metavar="COMMAND"
            )
         ],
         extra_args: Annotated[
             typer.Context,
             typer.Argument(
                 help="Extra arguments passed to COMMAND",
                 metavar="EXTRA_ARGS..."),
         ]) -> None:
    """This should use subprocess.run..."""
    print(f"Invoking {cmd} with: {extra_args.args}")


if __name__ == "__main__":
    app()

Description

I want to create a wrapper around other command, in such way that all unknown arguments passed to the wrapper are passed to said command. I can do that with the help of context_settings={"allow_extra_args": True, "ignore_unknown_options": True}, as described in the documentation: Using the Context: Configuring the context (see the example code, which is very simplified).

What I'd like to have, in the --help output, some placeholder for those extra arguments in the "Usage:", and have the argument described. For example, the usage for git log is

git log [<options>] [<revision-range>] [[--] <path>…​]

I have tried using typer.Argument (shown in the example) and type.Option to provide metavar for "Usage:", and help for detailed help output. Neither works; the output looks like this:

Usage: python typer_issue_example.py [OPTIONS] COMMAND

  This should use subprocess.run...

Arguments:
  COMMAND  Command to invoke  [required]

Options:

What I would like to see would be:

Usage: python typer_issue_example.py [OPTIONS] COMMAND EXTRA_ARGS...

  This should use subprocess.run...

Arguments:
  COMMAND       Command to invoke  [required]
  EXTRA_ARGS...   Extra arguments passed to COMMAND

Options:

I propose adding typer.Parameter (following the name of similar think in Click) to handle this specific purpose.

Note that this issue is different in goal from issue #454 - there the goal was to implement multiple-valued argument / option. It was resolved with description of how to achieve desired goal in a different way (i.e.., the workaround), rather than the solution to the question as stated.

Operating System

Windows

Operating System Details

Windows 10 Home, version 22H2, build 19045.4651

(the feature request is independent of the operating system)

Typer Version

typer 0.12.3

Python Version

Python 3.10.4

Additional Context

No response