test_file_error may fail if TMPDIR is too long

[booxter]

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 documentation, with the integrated search.
• I already searched in Google "How to X" and didn't find any information.
• I already read and followed all the tutorials in the docs and didn't find an answer.

Example Code

Not applicable.

Description

When running unit tests in nixpkgs build env, the test case may fail:

=================================== FAILURES ===================================
_______________________________ test_file_error ________________________________
[gw31] linux -- Python 3.14.8 /nix/store/84sbnj658b2ci0fzabvxaclwz9x6xhqw-python3-3.14.8/bin/python3.14

monkeypatch = <_pytest.monkeypatch.MonkeyPatch object at 0x7fffeff768b0>
tmp_path = PosixPath('/build/pytest-of-nixbld/pytest-0/popen-gw31/test_file_error0')

    def test_file_error(monkeypatch, tmp_path: Path) -> None:
        file_path = tmp_path / "cannot-open.txt"
    
        def fake_open(path, *args, **kwargs):
            if Path(path) == file_path:
                raise OSError()
    
        monkeypatch.setattr("builtins.open", fake_open)
        result = runner.invoke(app, ["write-text", f"--file-out={file_path}"])
        assert result.exit_code == 1
        assert "Could not open file" in result.output
>       assert "cannot-open.txt" in result.output
E       AssertionError: assert 'cannot-open.txt' in '╭─ Error ──────────────────────────────────────────────────────────────────────╮\n│ Could not open file              ..
.                                 │\n╰──────────────────────────────────────────────────────────────────────────────╯\n'
E        +  where '╭─ Error ──────────────────────────────────────────────────────────────────────╮\n│ Could not open file              ...                                 
│\n╰──────────────────────────────────────────────────────────────────────────────╯\n' = <Result SystemExit(1)>.output

tests/test_types_file.py:282: AssertionError
=========================== short test summary info ============================
FAILED tests/test_types_file.py::test_file_error - AssertionError: assert 'cannot-open.txt' in '╭─ Error ─────────────────────...
============ 1 failed, 1372 passed, 28 skipped, 2 xfailed in 5.31s =============

It happens because TMPDIR is /build/pytest-of-nixbld/pytest-0/popen-gw31/test_file_error0 and it pushes Rich library to wrap the file name. Assert then fails.

Operating System

Linux

Operating System Details

No response

Project Version

0.27.2

Python Version

3.14

Additional Context

You can pull the fix here: 2c40f62

[TanbirRamim]

I can reproduce this. It depends on the panel width more than the path itself: Rich wraps the error box at 80 columns and splits the path wherever it lands, so with some TMPDIR lengths "cannot-open.txt" ends up broken across two lines. Until your fix lands, a wider console makes it pass in the nix build env:

export COLUMNS=200   # TERMINAL_WIDTH=200 also works, typer reads it for the rich console

Your commit looks like the right long-term fix since the test shouldn't depend on terminal width.

[booxter]

To add some color: in nix environment we are seeing this test case failing sporadically because the full path was either fitting the panel length or not depending on which xdist worker it landed on: if the worker was 0-9, then the path was still not split. If the test case landed on worker 10+, the length became 1 character too long and got split.

This is because the temporary directory path includes the worker number, and this additional digit pushed the test case into broken state.

Which means that another workaround is reducing the number of xdist workers to 10. :)

[TanbirRamim]

oh nice, that explains why it was flaky and not just broken. one extra digit in the worker id pushing it over the edge is very sneaky