[FEATURE] Make typer compatible with PEP 563

[lorddaedra]

Describe the bug

Traceback (most recent call last):
...
  File "/usr/local/lib/python3.8/site-packages/typer/main.py", line 586, in get_click_type
    raise RuntimeError(f"Type not yet supported: {annotation}")  # pragma no cover
RuntimeError: Type not yet supported: str

https://www.python.org/dev/peps/pep-0563/

To Reproduce

Add

from __future__ import annotations

...

[tiangolo]

This is now supported as of version 0.2.1 🎉 🚀

[github-actions]

Assuming the original issue was solved, it will be automatically closed now. But feel free to add more comments or create new issues.

[wizard-28]

This does not work anymore

Sample code:

from __future__ import annotations

import typer

app = typer.Typer()


def main():
    app()


@app.command()
def test(flag: list[str] = typer.Option(None, "--flag", "-f", help="A flag")):
    print(flag)


if __name__ == "__main__":
    main()

Error:

Traceback (most recent call last):
  File "test.py", line 18, in <module>
    main()
  File "test.py", line 9, in main
    app()
  File "/home/pop-os/.cache/pypoetry/virtualenvs/nala-j_krjJMS-py3.8/lib/python3.8/site-packages/typer/main.py", line 214, in __call__
    return get_command(self)(*args, **kwargs)
  File "/home/pop-os/.cache/pypoetry/virtualenvs/nala-j_krjJMS-py3.8/lib/python3.8/site-packages/typer/main.py", line 239, in get_command
    click_command = get_command_from_info(typer_instance.registered_commands[0])
  File "/home/pop-os/.cache/pypoetry/virtualenvs/nala-j_krjJMS-py3.8/lib/python3.8/site-packages/typer/main.py", line 425, in get_command_from_info
    ) = get_params_convertors_ctx_param_name_from_function(command_info.callback)
  File "/home/pop-os/.cache/pypoetry/virtualenvs/nala-j_krjJMS-py3.8/lib/python3.8/site-packages/typer/main.py", line 401, in get_params_convertors_ctx_param_name_from_function
    parameters = get_params_from_function(callback)
  File "/home/pop-os/.cache/pypoetry/virtualenvs/nala-j_krjJMS-py3.8/lib/python3.8/site-packages/typer/utils.py", line 11, in get_params_from_function
    type_hints = get_type_hints(func)
  File "/usr/lib/python3.8/typing.py", line 1264, in get_type_hints
    value = _eval_type(value, globalns, localns)
  File "/usr/lib/python3.8/typing.py", line 270, in _eval_type
    return t._evaluate(globalns, localns)
  File "/usr/lib/python3.8/typing.py", line 518, in _evaluate
    eval(self.__forward_code__, globalns, localns),
  File "<string>", line 1, in <module>
TypeError: 'type' object is not subscriptable

Related issue: #371