Issue #19990: Added tests for the imghdr module.
Based on patch by Claudiu Popa.
diff --git a/Lib/test/test_imghdr.py b/Lib/test/test_imghdr.py
new file mode 100644
index 0000000..9306d9b
--- /dev/null
+++ b/Lib/test/test_imghdr.py
@@ -0,0 +1,120 @@
+import imghdr
+import io
+import sys
+import unittest
+from test.test_support import findfile, TESTFN, unlink, run_unittest
+
+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)
+ ufilename = filename.decode(sys.getfilesystemencoding())
+ self.assertEqual(imghdr.what(ufilename), 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)
+
+ 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 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_missing_file(self):
+ with self.assertRaises(IOError):
+ 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(IOError) as cm:
+ imghdr.what(stream)
+
+def test_main():
+ run_unittest(TestImghdr)
+
+if __name__ == '__main__':
+ test_main()