import imghdr
import io
import os
import unittest
import warnings
from test.support import findfile, TESTFN, unlink
TEST_FILES = (
('python.png', 'png'),
('python.gif', 'gif'),
('python.bmp', 'bmp'),
('python.ppm', 'ppm'),
('python.pgm', 'pgm'),
('python.pbm', 'pbm'),
('python.jpg', 'jpeg'),
('python.ras', 'rast'),
('python.sgi', 'rgb'),
('python.tiff', 'tiff'),
('python.xbm', 'xbm')
)
class UnseekableIO(io.FileIO):
def tell(self):
raise io.UnsupportedOperation
def seek(self, *args, **kwargs):
raise io.UnsupportedOperation
class TestImghdr(unittest.TestCase):
@classmethod
def setUpClass(cls):
cls.testfile = findfile('python.png', subdir='imghdrdata')
with open(cls.testfile, 'rb') as stream:
cls.testdata = stream.read()
def tearDown(self):
unlink(TESTFN)
def test_data(self):
for filename, expected in TEST_FILES:
filename = findfile(filename, subdir='imghdrdata')
self.assertEqual(imghdr.what(filename), expected)
with open(filename, 'rb') as stream:
self.assertEqual(imghdr.what(stream), expected)
with open(filename, 'rb') as stream:
data = stream.read()
self.assertEqual(imghdr.what(None, data), expected)
self.assertEqual(imghdr.what(None, bytearray(data)), expected)
def test_register_test(self):
def test_jumbo(h, file):
if h.startswith(b'eggs'):
return 'ham'
imghdr.tests.append(test_jumbo)
self.addCleanup(imghdr.tests.pop)
self.assertEqual(imghdr.what(None, b'eggs'), 'ham')
def test_file_pos(self):
with open(TESTFN, 'wb') as stream:
stream.write(b'ababagalamaga')
pos = stream.tell()
stream.write(self.testdata)
with open(TESTFN, 'rb') as stream:
stream.seek(pos)
self.assertEqual(imghdr.what(stream), 'png')
self.assertEqual(stream.tell(), pos)
def test_bad_args(self):
with self.assertRaises(TypeError):
imghdr.what()
with self.assertRaises(AttributeError):
imghdr.what(None)
with self.assertRaises(TypeError):
imghdr.what(self.testfile, 1)
with self.assertRaises(AttributeError):
imghdr.what(os.fsencode(self.testfile))
with open(self.testfile, 'rb') as f:
with self.assertRaises(AttributeError):
imghdr.what(f.fileno())
def test_invalid_headers(self):
for header in (b'\211PN\r\n',
b'\001\331',
b'\x59\xA6',
b'cutecat',
b'000000JFI',
b'GIF80'):
self.assertIsNone(imghdr.what(None, header))
def test_string_data(self):
with warnings.catch_warnings():
warnings.simplefilter("ignore", BytesWarning)
for filename, _ in TEST_FILES:
filename = findfile(filename, subdir='imghdrdata')
with open(filename, 'rb') as stream:
data = stream.read().decode('latin1')
with self.assertRaises(TypeError):
imghdr.what(io.StringIO(data))
with self.assertRaises(TypeError):
imghdr.what(None, data)
def test_missing_file(self):
with self.assertRaises(FileNotFoundError):
imghdr.what('missing')
def test_closed_file(self):
stream = open(self.testfile, 'rb')
stream.close()
with self.assertRaises(ValueError) as cm:
imghdr.what(stream)
stream = io.BytesIO(self.testdata)
stream.close()
with self.assertRaises(ValueError) as cm:
imghdr.what(stream)
def test_unseekable(self):
with open(TESTFN, 'wb') as stream:
stream.write(self.testdata)
with UnseekableIO(TESTFN, 'rb') as stream:
with self.assertRaises(io.UnsupportedOperation):
imghdr.what(stream)
def test_output_stream(self):
with open(TESTFN, 'wb') as stream:
stream.write(self.testdata)
stream.seek(0)
with self.assertRaises(OSError) as cm:
imghdr.what(stream)
if __name__ == '__main__':
unittest.main()