Mark OSX home directory as a posix path

[twiggler]

This fixes an issue where the home directory could not be found when running dissect on windows.

@pyrco also helped

Closes #866

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.26%. Comparing base (38f84b2) to head (53ac69c).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #867   +/-   ##
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  Coverage   76.26%   76.26%           
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  Files         312      312           
  Lines       26788    26789    +1     
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+ Hits        20430    20431    +1     
  Misses       6358     6358           

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[JSCU-CNI]

This should not be necessary if home is an instance of TargetPath.

[pyrco]

It should not be needed either way as the flow path __eq__ can deal with directly comparing against strings.

[twiggler]

@pyrco @JSCU-CNI The point is to bypass the overriden __eq__ method

By comparing to the string representation when the test is running under windows, I am ensuring that the home directory is stored in posix_format; when it is not, this assertion will fail because the string representation would contain backslashes. The __eq__ would pass, even it is a windows_format.

Effectively, this guards against regressions, where the home path would be interpreted as a windows path when running under windows.

I have added a comment to the code to clarify.

Alternatively, i can add an explicit type assertion for posix_path. But perhaps it is better to check behavior than types.

[twiggler]

(Added comment)

@pyrco @JSCU-CNI The right-hand term of the or operator https://github.com/fox-it/flow.record/blob/1701dcf6ff77d99923ef2523cb258fc75ade68e1/flow/record/fieldtypes/__init__.py#L698

makes the comparison through __eq__ more lenient than directly comparing to the string representation.

i.e. more concretely, windows_path('/Users/dissect') == '/Users/dissect',
while str(windows_path('/Users/dissect')) == '\\Users\\dissect'

[pyrco]

Suggested change

	# When the test is running under windows, comparing to the string representation ensures
	# that the home directory is stored in posix format.
	# The __eq__ operator of the path class is too lenient.
	assert str(dissect_user.home) == "/var/empty"
	assert dissect_user.home == "/var/empty"

The flow.record paths were explicitly designed so we could do this in tests. No need for casts or comments.

[pyrco]

I think an explicit type check for posix_path to prevent regressions is merited as that is what it should be by definition.

[twiggler]

I have added an assertion for posix_path.

In the long term, I am still slightly unsatisfied by our current solution :)

• I think the original assertion assert dissect_user.home == "/var/empty" should have caught the bug on windows this pr fixes.
• Related, but I think adding type checks cause the test to become unnecessarily coupled to implementation details (in this case posix_path). Ideally, I think we should check for behavior. So I slightly prefer the str cast and the comparison to the string representation.

But perhaps this is only the first time we have a bug like this. I have made a note for future reference. Maybe we can discuss at a later time in person.