fix(tests): merge fixture always runs merge_func; merge_cli has path and output bugs

[SashankBhamidi]

Three bugs in tests/conftest.py mean the CLI code path is never actually tested.

1. merge fixture ignores its parameter

@pytest.fixture(params=[merge_cli, merge_func])
def merge():
    return merge_func  # always returns merge_func regardless of param

All [merge_cli] test variants silently run merge_func instead.

2. merge_cli has a typo in the .ics suffix

calendar += "/.ics"  # should be ".ics"

3. merge_cli reads stdout instead of the output file

return icalendar.Calendar.from_ical(result.output)

result.output is the success message ("Successfully merged calendars into merged_calendar.ics\n"), not ICS data. The merged calendar is written to a file, not stdout.

[abe-101]

Is there there a failing test you seeing this in?

[SashankBhamidi]

No failing tests - that's the issue. All [merge_cli] tests silently run merge_func instead due to bug 1, so the CLI is never actually tested. Try breaking cli.py - tests still pass.

[abe-101]

Oof that's bad
Can I trouble you to open up a PR demonstrating that the tests, even when broken still pass?