cpiofile: Add unittest opening a symlink as fileobj

[bernhardkaindl]

Add two more checks to tests/test_cpiofile.py:

Test extracting a symlink from a seekable .cpio archive to a fileobj:

    # Test extracting a symlink to a file object:
    if archive_mode.startswith("|"):  # Non-seekable streams raise StreamError
        with pytest.raises(StreamError):
            archive.extractfile("symlink")
    else:  # Expect a seekable fileobj for this test (not a stream) to work:
        fileobj = archive.extractfile("symlink")
        assert fileobj and fileobj.read() == binary_data

Run all tests not just using a passed cpio fileobj, but also an acutal cpio file archive:

    for comp in ["cpio", "gz", "bz2", "xz"]:
        for filetype in [":", "|"]:
            if comp == "xz" and filetype == ":":
                continue  # streaming xz is not implemented (supported only as file)
            check_archive_mode(filetype + comp, fs)
            if filetype == "|":
+               check_archive_mode(filetype + comp, fs, filename="archive." + comp)

Changes to tests/test_cpiofile.py

• Refactor creating the cpio archive for the test into a reusable function
• Improve it to also be able to create an actual file besides working with file objects.
• Improve the tests to test both, cpio archive file objects and real cpio files.
• Cover the changed lines in cpiofile.py which obsolete a blank # type: ignore comment

Changes to xcp/cpiofile.py

• Replace the blank # type: ignore comment with an assertion and refactor it to simplify the code
  • Uses the fact that CpioFile.extract() accepts the member to extract as string
    • It does not have to be a member type:
      • Passing the string simplifies the code and obsoletes the need for the blank type: ignore

[coveralls]

Pull Request Test Coverage Report for Build 9072409400

Details

• 2 of 2 (100.0%) changed or added relevant lines in 1 file are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.2%) to 83.67%

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Files with Coverage Reduction	New Missed Lines	%
xcp/cpiofile.py	1	75.56%

Totals
Change from base Build 9072339625:	0.2%
Covered Lines:	2818
Relevant Lines:	3368

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💛 - Coveralls