def test_header_read_restore(self):
# Test that reading a header restores the file position
trk_fname = DATA['simple_trk_fname']
bio = BytesIO()
bio.write(b'Along my very merry way')
hdr_pos = bio.tell()
hdr_from_fname = TrkFile._read_header(trk_fname)
with open(trk_fname, 'rb') as fobj:
bio.write(fobj.read())
bio.seek(hdr_pos)
# Check header is as expected
hdr_from_fname['_offset_data'] += hdr_pos # Correct for start position
assert_arr_dict_equal(TrkFile._read_header(bio), hdr_from_fname)
# Check fileobject file position has not changed
assert_equal(bio.tell(), hdr_pos)
def test_is_supported_detect_format():
# Test is_supported and detect_format functions
# Empty file/string
f = BytesIO()
assert_false(nib.streamlines.is_supported(f))
assert_false(nib.streamlines.is_supported(""))
assert_true(nib.streamlines.detect_format(f) is None)
assert_true(nib.streamlines.detect_format("") is None)
# Valid file without extension
for tfile_cls in nib.streamlines.FORMATS.values():
f = BytesIO()
f.write(tfile_cls.MAGIC_NUMBER)
f.seek(0, os.SEEK_SET)
assert_true(nib.streamlines.is_supported(f))
assert_true(nib.streamlines.detect_format(f) is tfile_cls)
# Wrong extension but right magic number
for tfile_cls in nib.streamlines.FORMATS.values():
with tempfile.TemporaryFile(mode="w+b", suffix=".txt") as f:
f.write(tfile_cls.MAGIC_NUMBER)
f.seek(0, os.SEEK_SET)
assert_true(nib.streamlines.is_supported(f))
assert_true(nib.streamlines.detect_format(f) is tfile_cls)
# Good extension but wrong magic number
for ext, tfile_cls in nib.streamlines.FORMATS.items():
with tempfile.TemporaryFile(mode="w+b", suffix=ext) as f:
f.write(b"pass")
f.seek(0, os.SEEK_SET)
assert_false(nib.streamlines.is_supported(f))
assert_true(nib.streamlines.detect_format(f) is None)
# Wrong extension, string only
f = "my_tractogram.asd"
assert_false(nib.streamlines.is_supported(f))
assert_true(nib.streamlines.detect_format(f) is None)
# Good extension, string only
for ext, tfile_cls in nib.streamlines.FORMATS.items():
f = "my_tractogram" + ext
assert_true(nib.streamlines.is_supported(f))
assert_equal(nib.streamlines.detect_format(f), tfile_cls)
# Extension should not be case-sensitive.
for ext, tfile_cls in nib.streamlines.FORMATS.items():
f = "my_tractogram" + ext.upper()
assert_true(nib.streamlines.detect_format(f) is tfile_cls)
