def test_stream(self):
# guess content types from extension
descriptor = AttachableDescriptor(io.BytesIO(b'Simple text'), extension='.txt')
self.assertIsInstance(descriptor, StreamDescriptor)
self.assertEqual(descriptor.content_type, 'text/plain')
descriptor.seek(2)
self.assertEqual(descriptor.tell(), 2)
descriptor.seek(0, os.SEEK_END)
self.assertEqual(descriptor.tell(), 11)
# guess extension from original filename
descriptor = AttachableDescriptor(io.BytesIO(b'Simple text'), original_filename='letter.pdf')
self.assertEqual(descriptor.extension, '.pdf')
# guess extension from content type
descriptor = AttachableDescriptor(io.BytesIO(b'Simple text'), content_type='application/json')
self.assertEqual(descriptor.extension, '.json')
self.assertRaises(DescriptorOperationError, lambda: descriptor.filename)
def test_non_seekable(self):
class NonSeekableStream(io.BytesIO):
def seekable(self, *args, **kwargs):
return False
inp = b'abcdefghijklmnopqrstuvwxyz'
descriptor = AttachableDescriptor(NonSeekableStream(inp),
header_buffer_size=10)
# Fetching header, it forces to cache header_buffer_size bytes from
# header.
buffer = descriptor.get_header_buffer()
self.assertEqual(buffer, b'abcdefghij')
# fetching again to test the cache functionality
buffer = descriptor.get_header_buffer()
self.assertEqual(buffer, b'abcdefghij')
out = b''
out += descriptor.read(9)
self.assertEqual(descriptor.tell(), 9)
out += descriptor.read(11)
self.assertEqual(descriptor.tell(), 20)
out += descriptor.read(10)
self.assertEqual(out, inp)
# Max length error
descriptor = AttachableDescriptor(NonSeekableStream(inp),
header_buffer_size=24,
max_length=20)
buffer = descriptor.get_header_buffer()
self.assertEqual(buffer, b'abcdefghijklmnopqrstuvwx')
self.assertRaises(MaximumLengthIsReachedError, descriptor.read, 1)
# Test getting header buffer after read on non-seekable streams.
descriptor = AttachableDescriptor(NonSeekableStream(inp),
header_buffer_size=10,
max_length=20)
self.assertEqual(descriptor.read(10), b'abcdefghij')
self.assertRaises(DescriptorOperationError,
descriptor.get_header_buffer)