Bug: PowerShell Path autocompletion breaks Typer

[svankan]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the Typer documentation, with the integrated search.
• I already searched in Google "How to X in Typer" and didn't find any information.
• I already read and followed all the tutorials in the docs and didn't find an answer.
• I already checked if it is not related to Typer but to Click.

Commit to Help

• I commit to help with one of those options 👆

Example Code

from pathlib import Path
from typing import Annotated

import typer

app = typer.Typer()


@app.command()
def main(config: Annotated[Path | None, typer.Option()] = None):
    if config is None:
        print("No config file")
        raise typer.Abort()
    if config.is_file():
        text = config.read_text()
        print(f"Config file contents: {text}")
    elif config.is_dir():
        print("Config is a directory, will use all its config files")
    elif not config.exists():
        print("The config doesn't exist")


if __name__ == "__main__":
    app()

Description

Tab completion does not work correctly with PowerShell (pwsh).

Operating System

Linux and Windows 11

Operating System Details

Ubuntu 24.04.3 WSL in Windows 11
Windows 11
PowerShell version 7.6.1

Typer Version

0.25.0

Python Version

3.14.4

Additional Context

Minimal Reproducible Example

1. Create project with Python uv.
   uv init --package tabtyper cd tabtyper
2. Replace Python file
   nano -w src/tabtyper/__init__.py
   Use the Path parameter example from the Typer docs:
   https://typer.tiangolo.com/tutorial/parameter-types/path/#__tabbed_1_1
   (unchanged, only pasted as-is)
3. Edit pyproject.toml
   [project.scripts]
tabtyper = "tabtyper.__init__:app"
4. Install Typer
   uv add typer
5. Activate venv (PowerShell)
   pwsh
& ./.venv/bin/activate.ps1
uv pip list
   Behavior Before Manual Completion Install (✅ works)
   tabtyper --config ./pyproject.toml
   Steps:

Press Arrow Up
Delete "l" in pyproject.toml
Press TAB TAB
pyproject.toml is suggested correctly
Press Enter

✅ Works as expected
Install completion manually
tabtyper --show-completion pwsh > tabtypercompletion.ps1
. ./tabtypercompletion.ps1
Steps:

Press Arrow Up
Delete "l" in pyproject.toml
Press TAB TAB
Press Enter

Actual result

❌ No command output
❌ tabtyper --help → no output
Shell prompt returns silently

Workaround
If cursor position is changed before tabbing, completion works again.
Steps:

Press Arrow Up
Press Arrow Left several times
Stop cursor over --config
Press TAB TAB
Press Enter

✅ Output appears correctly

Additional Observations
✅ Works correctly in Fish shell

On Windows PowerShell:

tabtyper -- TAB TAB shows no options
tabtyper --c TAB TAB correctly completes to --config

Expected Behavior

Path autocompletion should continue working normally after manual installation via --show-completion
tabtyper --help should never return no output