# ----------------------------------------------------------------------------
# Copyright (c) 2013--, scikit-bio development team.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file COPYING.txt, distributed with this software.
# ----------------------------------------------------------------------------

from io import StringIO
import io
import itertools
import os
import unittest
import warnings
import types
from tempfile import mkstemp

from skbio.io import (FormatIdentificationWarning, UnrecognizedFormatError,
                      ArgumentOverrideWarning, io_registry, sniff,
                      create_format)
from skbio.io.registry import (IORegistry, FileSentinel, Format,
                               DuplicateRegistrationError,
                               InvalidRegistrationError)
from skbio.util import get_data_path
from skbio.util._exception import TestingUtilError
from skbio import DNA, read, write


class TestClass:
    def __init__(self, l):
        self.list = l

    def __eq__(self, other):
        # They are only equal when the class is EXACTLY the same. We don't want
        # readers to return knockoff instances...
        return self.__class__ is other.__class__ and self.list == other.list

    def __repr__(self):
        return "%s(%s)" % (str(self.__class__.__name__), str(self.list))


class TestClassA(TestClass):
    pass


class TestClassB(TestClass):
    pass


class TestFormatAndIORegistry(unittest.TestCase):
    def test_add_duplicate_format(self):
        f = Format('Example')
        r = IORegistry()
        r.add_format(f)
        with self.assertRaises(DuplicateRegistrationError):
            r.add_format(Format('Example'))


class RegistryTest(unittest.TestCase):
    def setUp(self):
        self.registry = IORegistry()
        self.fd1, self.fp1 = mkstemp()
        self.fd2, self.fp2 = mkstemp()

    def tearDown(self):
        os.remove(self.fp1)
        os.close(self.fd1)
        os.remove(self.fp2)
        os.close(self.fd2)


class TestRegisterAndGetReader(RegistryTest):
    def test_get_reader_no_match(self):
        self.assertIs(None, self.registry.get_reader('not_a_format',
                                                     TestClass))

    def test_get_reader_when_only_writer_exists(self):
        format1 = self.registry.create_format('format1')

        @format1.writer(TestClass)
        def format_writer(fh):
            return

        self.assertEqual(None, self.registry.get_reader('format', TestClass))

    def test_register_reader_on_many(self):
        format1 = self.registry.create_format('format1')
        format2 = self.registry.create_format('format2')
        format3 = self.registry.create_format('format3')
        format4 = self.registry.create_format('format4', encoding='binary')
        format5 = self.registry.create_format('format5', encoding='binary')

        @format1.reader(TestClassA)
        def format1_reader(fh):
            return

        @format1.reader(TestClassB)
        def format1_reader_b(fh):
            return

        @format2.reader(TestClassA)
        def format2_reader(fh):
            return

        @format3.reader(TestClassB)
        def format3_reader(fh):
            return

        @format4.reader(TestClassA)
        def format4_reader(fh):
            return

        @format4.reader(TestClassB)
        def format4_reader_b(fh):
            return

        @format5.reader(None)
        def format5_reader(fh):
            return

        self.assertIs(format1_reader,
                      self.registry.get_reader('format1', TestClassA))

        self.assertIs(format1_reader_b,
                      self.registry.get_reader('format1', TestClassB))

        self.assertIs(format2_reader,
                      self.registry.get_reader('format2', TestClassA))

        self.assertIs(None, self.registry.get_reader('format2', TestClassB))

        self.assertIs(None, self.registry.get_reader('format3', TestClassA))

        self.assertIs(format3_reader,
                      self.registry.get_reader('format3', TestClassB))

        self.assertIs(format4_reader,
                      self.registry.get_reader('format4', TestClassA))

        self.assertIs(format4_reader_b,
                      self.registry.get_reader('format4', TestClassB))

        self.assertIs(format5_reader,
                      self.registry.get_reader('format5', None))

        self.assertIs(None, self.registry.get_reader('format5', TestClassA))

        self.assertIs(None, self.registry.get_reader('format5', TestClassB))

    def test_register_reader_over_existing(self):
        format1 = self.registry.create_format('format1')
        with self.assertRaises(DuplicateRegistrationError) as cm:
            @format1.reader(TestClassA)
            def format1_reader(fh):
                return

            @format1.reader(TestClassA)
            def duplicate_format1_reader(fh):
                return

        self.assertTrue('format1' in str(cm.exception))
        self.assertTrue('reader' in str(cm.exception))
        self.assertTrue(TestClassA.__name__ in str(cm.exception))

    def test_register_reader_over_existing_override(self):
        format1 = self.registry.create_format('format1')

        @format1.reader(TestClassA)
        def format1_reader(fh):
            return

        self.assertIs(format1_reader,
                      self.registry.get_reader('format1', TestClassA))

        @format1.reader(TestClassA, override=True)
        def duplicate_format1_reader(fh):
            return

        self.assertIs(duplicate_format1_reader,
                      self.registry.get_reader('format1', TestClassA))

    def test_mistype_reader_registration(self):
        format1 = self.registry.create_format('format1')

        with self.assertRaises(InvalidRegistrationError):
            @format1.reader
            def left_out_parens(fh):
                return


class TestRegisterAndGetWriter(RegistryTest):
    def test_get_writer_no_match(self):
        self.assertEqual(None, self.registry.get_writer('not_a_format',
                                                        TestClass))

    def test_get_writer_when_only_reader_exists(self):
        format = self.registry.create_format('format')

        @format.reader(TestClass)
        def format_reader(fh):
            return

        self.assertEqual(None, self.registry.get_writer('format', TestClass))

    def test_register_writer_on_many(self):
        format1 = self.registry.create_format('format1')
        format2 = self.registry.create_format('format2')
        format3 = self.registry.create_format('format3')
        format4 = self.registry.create_format('format4', encoding='binary')
        format5 = self.registry.create_format('format5', encoding='binary')

        @format1.writer(TestClassA)
        def format1_writer(obj, fh):
            return

        @format1.writer(TestClassB)
        def format1_writer_b(obj, fh):
            return

        @format2.writer(TestClassA)
        def format2_writer(obj, fh):
            return

        @format3.writer(TestClassB)
        def format3_writer(obj, fh):
            return

        @format4.writer(TestClassA)
        def format4_writer(fh):
            return

        @format4.writer(TestClassB)
        def format4_writer_b(fh):
            return

        @format5.writer(None)
        def format5_writer(fh):
            return

        self.assertEqual(format1_writer,
                         self.registry.get_writer('format1', TestClassA))

        self.assertEqual(format1_writer_b,
                         self.registry.get_writer('format1', TestClassB))

        self.assertEqual(format2_writer,
                         self.registry.get_writer('format2', TestClassA))

        self.assertEqual(None,
                         self.registry.get_writer('format2', TestClassB))

        self.assertEqual(None,
                         self.registry.get_writer('format3', TestClassA))

        self.assertEqual(format3_writer,
                         self.registry.get_writer('format3', TestClassB))

        self.assertIs(format4_writer,
                      self.registry.get_writer('format4', TestClassA))

        self.assertIs(format4_writer_b,
                      self.registry.get_writer('format4', TestClassB))

        self.assertIs(format5_writer,
                      self.registry.get_writer('format5', None))

        self.assertIs(None, self.registry.get_writer('format5', TestClassA))

        self.assertIs(None, self.registry.get_writer('format5', TestClassB))

    def test_register_writer_over_existing(self):
        format1 = self.registry.create_format('format1')
        with self.assertRaises(DuplicateRegistrationError) as cm:
            @format1.writer(TestClassA)
            def format1_writer(obj, fh):
                return

            @format1.writer(TestClassA)
            def duplicate_format1_writer(obj, fh):
                return

        self.assertTrue('format1' in str(cm.exception))
        self.assertTrue('writer' in str(cm.exception))
        self.assertTrue(TestClassA.__name__ in str(cm.exception))

    def test_register_writer_over_existing_override(self):
        format1 = self.registry.create_format('format1')

        @format1.writer(TestClassA)
        def format1_writer(obj, fh):
            return

        self.assertIs(format1_writer,
                      self.registry.get_writer('format1', TestClassA))

        @format1.writer(TestClassA, override=True)
        def duplicate_format1_writer(obj, fh):
            return

        self.assertIs(duplicate_format1_writer,
                      self.registry.get_writer('format1', TestClassA))

    def test_mistype_writer_registration(self):
        format1 = self.registry.create_format('format1')

        with self.assertRaises(InvalidRegistrationError):
            @format1.writer
            def left_out_parens(fh):
                return


class TestRegisterAndGetSniffer(RegistryTest):
    def test_get_sniffer_no_match(self):
        self.assertEqual(None, self.registry.get_sniffer('not_a_format'))

    def test_register_sniffer_on_many(self):
        format1 = self.registry.create_format('format1')
        format2 = self.registry.create_format('format2')
        format3 = self.registry.create_format('format3', encoding='binary')

        @format1.sniffer()
        def format1_sniffer(fh):
            return '1' in fh.readline(), {}

        @format2.sniffer()
        def format2_sniffer(fh):
            return '2' in fh.readline(), {}

        @format3.sniffer()
        def format3_sniffer(fh):
            return '3' in fh.readline(), {}

        self.assertEqual(format1_sniffer,
                         self.registry.get_sniffer('format1'))

        self.assertEqual(format2_sniffer,
                         self.registry.get_sniffer('format2'))

        self.assertEqual(format3_sniffer,
                         self.registry.get_sniffer('format3'))

    def test_register_sniffer_over_existing(self):
        format1 = self.registry.create_format('format1')

        with self.assertRaises(DuplicateRegistrationError) as cm:
            @format1.sniffer()
            def format1_sniffer(fh):
                return False, {}

            @format1.sniffer()
            def duplicate_format1_sniffer(fh):
                return False, {}

        self.assertTrue('format1' in str(cm.exception))

    def test_register_sniffer_over_existing_override(self):
        format1 = self.registry.create_format('format1')

        @format1.sniffer()
        def format1_sniffer(fh):
            return False, {}

        self.assertIs(self.registry.get_sniffer('format1'), format1_sniffer)

        @format1.sniffer(override=True)
        def duplicate_format1_sniffer(fh):
            return False, {}

        self.assertIs(self.registry.get_sniffer('format1'),
                      duplicate_format1_sniffer)

    def test_sniffer_warns_on_exception(self):
        format = self.registry.create_format('format')

        @format.sniffer()
        def format_sniffer(fh):
            raise TestingUtilError("Sniffer will return False and warn.")

        fh = StringIO()
        sniffer = self.registry.get_sniffer('format')
        with warnings.catch_warnings(record=True):
            warnings.simplefilter("error")
            with self.assertRaises(FormatIdentificationWarning):
                sniffer(fh)

        with warnings.catch_warnings(record=True):
            warnings.simplefilter("ignore")
            result, kwargs = sniffer(fh)
            self.assertFalse(result)
            self.assertEqual({}, kwargs)

        fh.close()

    def test_mistype_sniffer_registration(self):
        format1 = self.registry.create_format('format1')

        with self.assertRaises(InvalidRegistrationError):
            @format1.sniffer
            def left_out_parens(fh):
                return


class TestListReadFormats(RegistryTest):
    def test_no_read_formats(self):
        format1 = self.registry.create_format('format1')

        @format1.reader(TestClassA)
        def this_isnt_on_clsB(fh):
            return

        self.assertEqual([], self.registry.list_read_formats(TestClassB))

    def test_one_read_format(self):
        format1 = self.registry.create_format('format1')

        @format1.reader(TestClass)
        def format1_cls(fh):
            return

        self.assertEqual(['format1'],
                         self.registry.list_read_formats(TestClass))

    def test_many_read_formats(self):
        format1 = self.registry.create_format('format1')
        format2 = self.registry.create_format('format2')
        format3 = self.registry.create_format('format3', encoding='binary')
        format4 = self.registry.create_format('format4')
        format5 = self.registry.create_format('format5', encoding='binary')

        @format1.reader(TestClassA)
        def format1_clsA(fh):
            return

        @format2.reader(TestClassA)
        def format2_clsA(fh):
            return

        @format3.reader(TestClassA)
        def format3_clsA(fh):
            return

        @format3.reader(TestClassB)
        def format3_clsB(fh):
            return

        @format4.reader(TestClassB)
        def format4_clsB(fh):
            return

        @format5.writer(TestClassA)
        def format5_clsA(fh):
            return

        formats = self.registry.list_read_formats(TestClassA)
        self.assertTrue('format1' in formats)
        self.assertTrue('format2' in formats)
        self.assertTrue('format3' in formats)
        self.assertTrue('format4' not in formats)
        self.assertTrue('format5' not in formats)


class TestListWriteFormats(RegistryTest):
    def test_no_write_formats(self):
        format1 = self.registry.create_format('format1')

        @format1.writer(TestClassA)
        def this_isnt_on_clsB(fh):
            return

        self.assertEqual([], self.registry.list_write_formats(TestClassB))

    def test_one_write_format(self):
        format1 = self.registry.create_format('format1')

        @format1.writer(TestClass)
        def format1_cls(fh):
            return

        self.assertEqual(['format1'],
                         self.registry.list_write_formats(TestClass))

    def test_many_write_formats(self):
        format1 = self.registry.create_format('format1')
        format2 = self.registry.create_format('format2')
        format3 = self.registry.create_format('format3', encoding='binary')
        format4 = self.registry.create_format('format4')
        format5 = self.registry.create_format('format5', encoding='binary')

        @format1.writer(TestClassA)
        def format1_clsA(fh):
            return

        @format2.writer(TestClassA)
        def format2_clsA(fh):
            return

        @format3.writer(TestClassA)
        def format3_clsA(fh):
            return

        @format3.writer(TestClassB)
        def format3_clsB(fh):
            return

        @format4.writer(TestClassB)
        def format4_clsB(fh):
            return

        @format5.reader(TestClassA)
        def format5_clsA(fh):
            return

        formats = self.registry.list_write_formats(TestClassA)

        self.assertTrue('format1' in formats)
        self.assertTrue('format2' in formats)
        self.assertTrue('format3' in formats)
        self.assertTrue('format4' not in formats)
        self.assertTrue('format5' not in formats)


class TestSniff(RegistryTest):
    def setUp(self):
        super(TestSniff, self).setUp()
        format1 = self.registry.create_format('format1')
        format2 = self.registry.create_format('format2')
        format3 = self.registry.create_format('format3')
        format4 = self.registry.create_format('format4')
        # No sniffer for this format:
        self.registry.create_format('format5')

        @format1.sniffer()
        def format1_sniffer(fh):
            return '1' in fh.readline(), {}

        @format2.sniffer()
        def format2_sniffer(fh):
            return '2' in fh.readline(), {}

        @format3.sniffer()
        def format3_sniffer(fh):
            return '3' in fh.readline(), {}

        @format4.sniffer()
        def format4_sniffer(fh):
            return '4' in fh.readline(), {}

        @format3.reader(TestClass)
        def reader3(fh):
            return

        @format4.reader(TestClass)
        def reader4(fh):
            return

    def test_no_matches(self):
        fh = StringIO("no matches here")
        with self.assertRaises(UnrecognizedFormatError) as cm:
            self.registry.sniff(fh)
        self.assertTrue(str(fh) in str(cm.exception))

        fh.close()

    def test_one_match(self):
        fh = StringIO("contains a 3")
        self.assertEqual('format3', self.registry.sniff(fh)[0])

    def test_many_matches(self):
        fh = StringIO("1234 will match all")
        with self.assertRaises(UnrecognizedFormatError) as cm:
            self.registry.sniff(fh)
        self.assertTrue("format1" in str(cm.exception))
        self.assertTrue("format2" in str(cm.exception))
        self.assertTrue("format3" in str(cm.exception))
        self.assertTrue("format4" in str(cm.exception))
        fh.close()

    def test_that_encoding_is_used(self):
        formatx = self.registry.create_format('formatx')

        fp = get_data_path('big5_file')

        @formatx.sniffer()
        def sniffer(fh):
            self.assertEqual('big5', fh.encoding)
            return True, {}

        fmt, _ = self.registry.sniff(fp, encoding='big5')
        self.assertEqual(fmt, 'formatx')

    def test_passing_newline_raises_error(self):
        formatx = self.registry.create_format('formatx')

        fp = get_data_path('real_file')

        @formatx.sniffer()
        def sniffer(fh):
            return True, {}

        with self.assertRaisesRegex(TypeError, '`newline`'):
            self.registry.sniff(fp, newline='\r')

    def test_non_default_encoding(self):
        big5_format = self.registry.create_format('big5_format',
                                                  encoding='big5')

        @big5_format.sniffer()
        def sniffer(fh):
            self.assertEqual(self._expected_encoding, fh.encoding)
            return True, {}

        self._expected_encoding = 'big5'
        fmt, _ = self.registry.sniff(self.fp1)
        self.assertEqual(fmt, 'big5_format')

        self._expected_encoding = 'UTF-8'
        fmt, _ = self.registry.sniff(self.fp1, encoding='UTF-8')
        self.assertEqual(fmt, 'big5_format')

    def test_non_default_newline(self):
        formatx = self.registry.create_format('formatx', newline='\r')

        fp = get_data_path('real_file')

        @formatx.sniffer()
        def sniffer(fh):
            self.assertEqual(fh.readlines(), ['a\nb\nc\nd\ne\n'])
            return True, {}

        fmt, _ = self.registry.sniff(fp)
        self.assertEqual(fmt, 'formatx')

    def test_position_not_mutated_real_file(self):
        formatx = self.registry.create_format('formatx')

        @formatx.sniffer()
        def sniffer(fh):
            return True, {}

        with io.open(get_data_path('real_file')) as fh:
            fh.seek(2)
            self.registry.sniff(fh)
            self.assertEqual(fh.tell(), 2)
            self.assertEqual('b\n', fh.readline())

    def test_position_not_mutated_fileish(self):
        formatx = self.registry.create_format('formatx')

        @formatx.sniffer()
        def sniffer(fh):
            return True, {}

        fh = StringIO('a\nb\nc\nd\n')
        fh.seek(2)
        self.registry.sniff(fh)
        self.assertEqual('b\n', fh.readline())

    def test_sniff_with_errors_in_sniffer(self):
        formatx = self.registry.create_format('formatx', encoding='ascii')

        @formatx.sniffer()
        def sniffer(fh):
            raise Exception("OH NO!")

        fp = get_data_path('big5_file')
        with warnings.catch_warnings(record=True):
            warnings.simplefilter('error')
            with self.assertRaises(FormatIdentificationWarning):
                fmt, _ = self.registry.sniff(fp)

    def test_sniff_with_encoding_errors(self):
        formatx = self.registry.create_format('formatx', encoding='ascii')

        @formatx.sniffer()
        def sniffer(fh):
            fh.read()
            return True, {}

        fp = get_data_path('big5_file')
        with self.assertRaises(UnrecognizedFormatError):
            fmt, _ = self.registry.sniff(fp, errors='strict')
        # errors is set to ignore by default, so our sniffer will return
        # true even though read() didn't entirely work for ascii
        fmt, _ = self.registry.sniff(fp)
        self.assertEqual(fmt, 'formatx')

    def test_binary_sniffer(self):
        binf = self.registry.create_format('binf', encoding='binary')

        @binf.sniffer()
        def sniffer(fh):
            self.assertIsInstance(fh, (io.BufferedReader, io.BufferedRandom))
            return True, {}

        fmt, _ = self.registry.sniff(self.fp1)
        self.assertEqual(fmt, 'binf')

    def test_text_sniffer(self):
        textf = self.registry.create_format('textf', encoding=None)

        @textf.sniffer()
        def sniffer(fh):
            self.assertIsInstance(fh, io.TextIOBase)
            return True, {}

        fmt, _ = self.registry.sniff(self.fp1)
        self.assertEqual(fmt, 'textf')

    def test_sniff_with_illegal_encoding(self):
        binf = self.registry.create_format('binf', encoding='binary')
        textf = self.registry.create_format('textf', encoding=None)

        @binf.sniffer()
        def binf_sniffer(fh):
            return True, {}

        @textf.sniffer()
        def textf_sniffer(fh):
            return True, {}

        # Should skip binary sniffers
        fmt, _ = self.registry.sniff(self.fp1, encoding=None)
        self.assertEqual(fmt, 'textf')
        # Should skip text sniffers
        fmt, _ = self.registry.sniff(self.fp1, encoding='binary')
        self.assertEqual(fmt, 'binf')

        with self.assertRaises(ValueError):
            self.registry.sniff(['some content\n'], encoding='binary')

        with self.assertRaises(ValueError):
            binf_sniffer(self.fp1, encoding=None)

        with self.assertRaises(ValueError):
            textf_sniffer(self.fp1, encoding='binary')

    def test_binary_fall_through(self):
        binf = self.registry.create_format('binf', encoding='binary')
        textf = self.registry.create_format('textf', encoding=None)

        @binf.sniffer()
        def binf_sniffer(fh):
            self._check_binf = True
            return False, {}

        @textf.sniffer()
        def textf_sniffer(fh):
            self._check_textf = True
            return True, {}

        self._check_binf = False
        self._check_textf = False

        fmt, _ = self.registry.sniff(self.fp1)
        self.assertEqual(fmt, 'textf')

        self.assertTrue(self._check_binf)
        self.assertTrue(self._check_textf)

    def test_sniff_gzip(self):
        expected = "This is some content\nIt occurs on more than one line\n"

        formata = self.registry.create_format('formata', encoding='binary')
        formatb = self.registry.create_format('formatb')
        formatc = self.registry.create_format('formatc')

        @formata.sniffer()
        def formata_sniffer(fh):
            self._check_f1 = True
            self.assertEqual(fh.read(), expected.encode('ascii'))
            return False, {}

        @formatb.sniffer()
        def formatb_sniffer(fh):
            self._check_f2 = True
            self.assertEqual(fh.read(), expected)
            return True, {}

        @formatc.sniffer()
        def formatc_sniffer(fh):
            self._check_f3 = True
            self.assertEqual(fh.read(), expected)
            return False, {}

        self._check_f1 = False
        self._check_f2 = False
        self._check_f3 = False
        self.registry.sniff(get_data_path('example_file.gz'))
        self.assertTrue(self._check_f1)
        self.assertTrue(self._check_f2)
        self.assertTrue(self._check_f3)

    def test_text_skip_binary(self):
        binf = self.registry.create_format('binf', encoding='binary')
        textf = self.registry.create_format('textf', encoding=None)

        @binf.sniffer()
        def binf_sniffer(fh):
            self._check_binf = True
            return True, {}

        @textf.sniffer()
        def textf_sniffer(fh):
            self._check_textf = True
            return True, {}

        self._check_binf = False
        self._check_textf = False

        fmt, _ = self.registry.sniff(['text'])
        self.assertEqual(fmt, 'textf')

        self.assertFalse(self._check_binf)
        self.assertTrue(self._check_textf)

        self._check_binf = False
        self._check_textf = False

        fmt, _ = self.registry.sniff(self.fp1, encoding=None)
        self.assertEqual(fmt, 'textf')

        self.assertFalse(self._check_binf)
        self.assertTrue(self._check_textf)

    def test_text_skip_text(self):
        binf = self.registry.create_format('binf', encoding='binary')
        textf = self.registry.create_format('textf', encoding=None)

        @binf.sniffer()
        def binf_sniffer(fh):
            self._check_binf = True
            return True, {}

        @textf.sniffer()
        def textf_sniffer(fh):
            self._check_textf = True
            return True, {}

        self._check_binf = False
        self._check_textf = False

        fmt, _ = self.registry.sniff(self.fp1, encoding='binary')
        self.assertEqual(fmt, 'binf')

        self.assertTrue(self._check_binf)
        self.assertFalse(self._check_textf)


class TestRead(RegistryTest):
    def test_format_and_into_are_none(self):
        fh = StringIO()
        with self.assertRaises(ValueError):
            self.registry.read(fh)

        fh.close()

    def test_format_is_none(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO('1\n2\n3\n4')

        @format1.sniffer()
        def sniffer(fh):
            return '1' in fh.readline(), {}

        @format1.reader(TestClass)
        def reader(fh):
            self.assertIsInstance(fh, io.TextIOBase)
            return TestClass([int(x) for x in fh.read().split('\n')])

        instance = self.registry.read(fh, into=TestClass)
        self.assertEqual(TestClass([1, 2, 3, 4]), instance)
        fh.close()

    def test_into_is_none_and_no_generator_reader(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO('1\n2\n3\n4')

        @format1.reader(TestClass)
        def reader(fh):
            self.assertIsInstance(fh, io.TextIOBase)
            return

        with self.assertRaisesRegex(UnrecognizedFormatError,
                                    "Cannot read 'format1'.*Possible.*include"
                                    ": TestClass"):
            self.registry.read(fh, format='format1')

    def test_into_is_none(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO('1\n2\n3\n4')

        @format1.reader(None)
        def reader(fh):
            self.assertIsInstance(fh, io.TextIOBase)
            yield from [int(x) for x in fh.read().split('\n')]

        generator = self.registry.read(fh, format='format1')
        self.assertIsInstance(generator, types.GeneratorType)
        first_run = True
        for a, b in zip(generator, [1, 2, 3, 4]):
            if first_run:
                fh.seek(3)
                first_run = False
            self.assertEqual(a, b)
            self.assertEqual(3, fh.tell())
        fh.close()

    def test_into_is_none_real_file(self):
        format1 = self.registry.create_format('format1')

        fp = self.fp1
        with open(fp, 'w') as fh:
            fh.write('1\n2\n3\n4')

        self._test_fh = None

        @format1.reader(None)
        def reader(fh):
            self._test_fh = fh
            yield from [int(x) for x in fh.read().split('\n')]

        generator = self.registry.read(fp, format='format1')
        for a, b in itertools.zip_longest(generator, [1, 2, 3, 4]):
            self.assertEqual(a, b)
        self.assertTrue(self._test_fh.closed)

    def test_reader_does_not_exist(self):
        fh = StringIO()
        with self.assertRaises(UnrecognizedFormatError) as cm:
            self.registry.read(fh, format='not_a_format', into=TestClass)

        self.assertTrue(TestClass.__name__ in str(cm.exception))
        self.assertTrue('not_a_format' in str(cm.exception))

        with self.assertRaises(UnrecognizedFormatError) as cm:
            self.registry.read(fh, format='not_a_format2')

        self.assertTrue('generator' in str(cm.exception))
        self.assertTrue('not_a_format2' in str(cm.exception))

    def test_reader_exists_with_verify_true(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO('1\n2\n3\n4')

        @format1.sniffer()
        def sniffer(fh):
            self.was_verified = True
            return '1' in fh.readline(), {}

        @format1.reader(TestClass)
        def reader(fh):
            return TestClass([int(x) for x in fh.read().split('\n')])

        self.was_verified = False
        instance = self.registry.read(fh, format='format1', into=TestClass,
                                      verify=True)
        self.assertEqual(TestClass([1, 2, 3, 4]), instance)
        self.assertTrue(self.was_verified)

        # Remove if read-context management is support in the future.
        fh.seek(0)

        self.was_verified = False
        instance = self.registry.read(fh, format='format1', into=TestClass)
        self.assertEqual(TestClass([1, 2, 3, 4]), instance)
        self.assertTrue(self.was_verified)

        fh.close()

    def test_warning_raised(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO('1\n2\n3\n4')

        @format1.sniffer()
        def sniffer(fh):
            self.was_verified = True
            return False, {}

        @format1.reader(TestClass)
        def reader(fh):
            return TestClass([int(x) for x in fh.read().split('\n')])

        with warnings.catch_warnings(record=True):
            warnings.simplefilter("error")
            with self.assertRaises(FormatIdentificationWarning):
                self.was_verified = False
                instance = self.registry.read(fh, format='format1',
                                              into=TestClass, verify=True)
                self.assertEqual(TestClass([1, 2, 3, 4]), instance)
                self.assertTrue(self.was_verified)

        with warnings.catch_warnings(record=True):
            warnings.simplefilter("error")
            with self.assertRaises(FormatIdentificationWarning):
                self.was_verified = False
                instance = self.registry.read(fh, format='format1',
                                              into=TestClass)
                self.assertEqual(TestClass([1, 2, 3, 4]), instance)
                self.assertTrue(self.was_verified)

        fh.close()

    def test_reader_exists_with_verify_false(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO('1\n2\n3\n4')

        @format1.sniffer()
        def sniffer(fh):
            self.was_verified = True
            return '1' in fh.readline(), {}

        @format1.reader(TestClass)
        def reader(fh):
            return TestClass([int(x) for x in fh.read().split('\n')])

        self.was_verified = False
        instance = self.registry.read(fh, format='format1', into=TestClass,
                                      verify=False)
        self.assertEqual(TestClass([1, 2, 3, 4]), instance)
        self.assertFalse(self.was_verified)
        fh.close()

    def test_reader_exists_real_file(self):
        format1 = self.registry.create_format('format1')

        fp = self.fp1
        with open(fp, 'w') as fh:
            fh.write('1\n2\n3\n4')

        @format1.sniffer()
        def sniffer(fh):
            return '1' in fh.readline(), {}

        @format1.reader(TestClass)
        def reader(fh):
            return TestClass([int(x) for x in fh.read().split('\n')])

        instance = self.registry.read(fp, format='format1', into=TestClass)
        self.assertEqual(TestClass([1, 2, 3, 4]), instance)

    def test_read_kwargs_passed_generator(self):
        format1 = self.registry.create_format('format1')

        @format1.sniffer()
        def sniffer(fh):
            return True, {'arg1': 15, 'arg2': 'abc'}

        @format1.reader(None)
        def reader(fh, **kwargs):
            self.assertEqual(kwargs['arg1'], 15)
            self.assertEqual(kwargs['arg2'], 'abc')
            self.assertEqual(kwargs['arg3'], [1])
            yield

        next(self.registry.read(StringIO(), format='format1', arg3=[1]))

    def test_read_kwargs_passed_and_override(self):
        format1 = self.registry.create_format('format1')

        @format1.sniffer()
        def sniffer(fh):
            return True, {'arg1': 15, 'arg2': 'abc', 'override': 30}

        @format1.reader(TestClass)
        def reader(fh, **kwargs):
            self.assertEqual(kwargs['arg1'], 15)
            self.assertEqual(kwargs['arg2'], 'abc')
            self.assertEqual(kwargs['arg3'], [1])
            return

        self.registry.read(StringIO('notempty'), into=TestClass, arg3=[1])

        with warnings.catch_warnings(record=True):
            warnings.simplefilter("error")
            # Should raise no warning and thus no error.
            self.registry.read(StringIO('notempty'), into=TestClass, arg3=[1],
                               override=30)
            # Should raise a warning and thus an error.
            with self.assertRaises(ArgumentOverrideWarning):
                self.registry.read(StringIO('notempty'), into=TestClass,
                                   arg3=[1], override=100)

    def test_that_encoding_is_used(self):
        format1 = self.registry.create_format('format1')

        fp = get_data_path('big5_file')

        @format1.sniffer()
        def sniffer(fh):
            return '\u4f60' in fh.readline(), {}

        @format1.reader(TestClass)
        def reader(fh):
            self.assertEqual(self._expected_enc, fh.encoding)
            return TestClass(fh.readlines())

        @format1.reader(None)
        def reader_gen(fh):
            self.assertEqual(self._expected_enc, fh.encoding)
            yield TestClass(fh.readlines())

        self._expected_enc = 'big5'
        instance = self.registry.read(fp, into=TestClass, encoding='big5')
        self.assertEqual(TestClass(['\u4f60\u597d\n']), instance)

        self._expected_enc = 'big5'
        gen = self.registry.read(fp, format='format1', encoding='big5')
        self.assertEqual(TestClass(['\u4f60\u597d\n']), next(gen))

    def test_non_default_encoding(self):
        format1 = self.registry.create_format('format1', encoding='big5')

        fp = get_data_path('big5_file')

        @format1.sniffer()
        def sniffer(fh):
            return True, {}

        @format1.reader(TestClass)
        def reader(fh):
            self.assertEqual(self._expected_enc, fh.encoding)
            return TestClass(fh.readlines())

        @format1.reader(None)
        def reader_gen(fh):
            self.assertEqual(self._expected_enc, fh.encoding)
            yield TestClass(fh.readlines())

        self._expected_enc = 'big5'
        instance = self.registry.read(fp, into=TestClass)
        self.assertEqual(TestClass(['\u4f60\u597d\n']), instance)

        gen = self.registry.read(fp, format='format1')
        self.assertEqual(TestClass(['\u4f60\u597d\n']), next(gen))
        gen.close()

        self._expected_enc = 'utf8'
        with self.assertRaises(UnicodeDecodeError):
            self.registry.read(fp, into=TestClass, encoding='utf8')

        with self.assertRaises(UnicodeDecodeError):
            self.registry.read(fp, format='format1', encoding='utf8')

    def test_passing_newline_raises_error(self):
        formatx = self.registry.create_format('formatx')

        fp = get_data_path('real_file')

        @formatx.sniffer()
        def sniffer(fh):
            return True, {}

        @formatx.reader(TestClass)
        def reader(fh):
            return TestClass(fh.readlines())

        @formatx.reader(None)
        def reader_gen(fh):
            yield TestClass(fh.readlines())

        with self.assertRaisesRegex(TypeError, '`newline`'):
            self.registry.read(fp, into=TestClass, newline='\r')

        with self.assertRaisesRegex(TypeError, '`newline`'):
            self.registry.read(fp, format='formatx', newline='\r')

    def test_non_default_newline(self):
        formatx = self.registry.create_format('formatx', newline='\r')

        fp = get_data_path('real_file')

        @formatx.sniffer()
        def sniffer(fh):
            return True, {}

        @formatx.reader(TestClass)
        def reader(fh):
            return TestClass(fh.readlines())

        @formatx.reader(None)
        def reader_gen(fh):
            yield TestClass(fh.readlines())

        instance = self.registry.read(fp, into=TestClass)
        self.assertEqual(instance, TestClass(['a\nb\nc\nd\ne\n']))

        gen = self.registry.read(fp, format='formatx')
        self.assertEqual(next(gen), TestClass(['a\nb\nc\nd\ne\n']))
        gen.close()

    def test_file_sentinel_many(self):
        format1 = self.registry.create_format('format1')

        extra = get_data_path('real_file')
        extra_2 = get_data_path('real_file_2')
        fh = StringIO('1\n2\n3\n4')

        @format1.sniffer()
        def sniffer(fh):
            return '1' in fh.readline(), {}

        @format1.reader(TestClass)
        def reader(fh, extra=FileSentinel, other=2, extra_2=FileSentinel):
            self.assertEqual('a\nb\nc\nd\ne\n', extra.read())
            self.assertEqual('!\n@\n#\n$\n%\nThe realest.\n', extra_2.read())
            return TestClass([int(x) for x in fh.read().split('\n')])

        instance = self.registry.read(fh, format='format1', into=TestClass,
                                      extra=extra, extra_2=extra_2)
        self.assertEqual(TestClass([1, 2, 3, 4]), instance)

        fh.close()

    def test_file_sentinel_converted_to_none(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO('1\n2\n3\n4')

        @format1.sniffer()
        def sniffer(fh):
            return '1' in fh.readline(), {}

        @format1.reader(TestClass)
        def reader(fh, extra=FileSentinel, other=2, extra_2=FileSentinel):
            self.assertIsNone(extra)
            self.assertIsNone(extra_2)
            return TestClass([int(x) for x in fh.read().split('\n')])

        instance = self.registry.read(fh, format='format1', into=TestClass)
        self.assertEqual(TestClass([1, 2, 3, 4]), instance)

        fh.close()

    def test_file_sentinel_pass_none(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO('1\n2\n3\n4')

        @format1.sniffer()
        def sniffer(fh):
            return '1' in fh.readline(), {}

        @format1.reader(TestClass)
        def reader(fh, extra=FileSentinel, other=2, extra_2=FileSentinel):
            self.assertIsNone(extra)
            self.assertIsNone(extra_2)
            return TestClass([int(x) for x in fh.read().split('\n')])

        instance = self.registry.read(fh, format='format1', into=TestClass,
                                      extra=None)
        self.assertEqual(TestClass([1, 2, 3, 4]), instance)

        fh.close()

    def test_file_sentinel_generator_many(self):
        format1 = self.registry.create_format('format1')

        extra = get_data_path('real_file')
        extra_2 = get_data_path('real_file_2')
        fh = StringIO('1\n2\n3\n4')

        @format1.sniffer()
        def sniffer(fh):
            return '1' in fh.readline(), {}

        @format1.reader(None)
        def reader(fh, extra=FileSentinel, other=2, extra_2=FileSentinel):
            self.assertEqual('a\nb\nc\nd\ne\n', extra.read())
            self.assertEqual('!\n@\n#\n$\n%\nThe realest.\n', extra_2.read())
            yield TestClass([int(x) for x in fh.read().split('\n')])

        gen = self.registry.read(fh, format='format1', extra=extra,
                                 extra_2=extra_2)
        self.assertEqual(TestClass([1, 2, 3, 4]), next(gen))

        fh.close()

    def test_file_sentinel_converted_to_none_generator(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO('1\n2\n3\n4')

        @format1.sniffer()
        def sniffer(fh):
            return '1' in fh.readline(), {}

        @format1.reader(None)
        def reader(fh, extra=FileSentinel, other=2, extra_2=FileSentinel):
            self.assertIsNone(extra)
            self.assertIsNone(extra_2)
            yield TestClass([int(x) for x in fh.read().split('\n')])

        gen = self.registry.read(fh, format='format1')
        self.assertEqual(TestClass([1, 2, 3, 4]), next(gen))

        fh.close()

    def test_file_sentinel_pass_none_generator(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO('1\n2\n3\n4')

        @format1.sniffer()
        def sniffer(fh):
            return '1' in fh.readline(), {}

        @format1.reader(None)
        def reader(fh, extra=FileSentinel, other=2, extra_2=FileSentinel):
            self.assertIsNone(extra)
            self.assertIsNone(extra_2)
            yield TestClass([int(x) for x in fh.read().split('\n')])

        gen = self.registry.read(fh, format='format1', extra=None)
        self.assertEqual(TestClass([1, 2, 3, 4]), next(gen))

        fh.close()

    def test_read_with_illegal_encoding(self):
        binf = self.registry.create_format('binf', encoding='binary')
        textf = self.registry.create_format('textf', encoding=None)

        @binf.sniffer()
        def binf_sniffer(fh):
            return True, {}

        @binf.reader(TestClass)
        def binf_reader(fh):
            return TestClass(['bin'])

        @binf.reader(None)
        def binf_reader_gen(fh):
            yield TestClass(['bin'])

        @textf.sniffer()
        def textf_sniffer(fh):
            return True, {}

        @textf.reader(TestClass)
        def textf_reader(fh):
            return TestClass(['text'])

        @textf.reader(None)
        def textf_reader_gen(fh):
            yield TestClass(['text'])

        # Should skip binary sniffers
        instance = self.registry.read(self.fp1, encoding=None, into=TestClass)
        self.assertEqual(instance, TestClass(['text']))
        gen = self.registry.read(self.fp1, encoding=None, format='textf')
        self.assertEqual(next(gen), TestClass(['text']))
        gen.close()
        # Should skip text sniffers
        instance = self.registry.read(self.fp1, encoding='binary',
                                      into=TestClass)
        self.assertEqual(instance, TestClass(['bin']))
        gen = self.registry.read(self.fp1, encoding='binary', format='binf')
        self.assertEqual(next(gen), TestClass(['bin']))
        gen.close()

        with self.assertRaises(ValueError):
            self.registry.read(['some content\n'], encoding='binary',
                               into=TestClass)

        with self.assertRaises(ValueError):
            self.registry.read(['some content\n'], format='textf',
                               encoding='binary', into=TestClass)

        with self.assertRaises(ValueError):
            self.registry.read(['some content\n'], format='textf',
                               encoding='binary', verify=False, into=TestClass)

        with self.assertRaises(ValueError):
            self.registry.read(['some content\n'], format='textf',
                               encoding='binary')

        with self.assertRaises(ValueError):
            self.registry.read(['some content\n'], format='textf',
                               encoding='binary', verify=False)

        with self.assertRaises(ValueError):
            self.registry.read(self.fp1, format='binf',
                               encoding=None, into=TestClass)

        with self.assertRaises(ValueError):
            self.registry.read(self.fp1, format='binf',
                               encoding=None, verify=False, into=TestClass)

        with self.assertRaises(ValueError):
            self.registry.read(self.fp1, format='binf',
                               encoding=None)

        with self.assertRaises(ValueError):
            self.registry.read(self.fp1, format='binf',
                               encoding=None, verify=False)

    def test_read_with_binary_encoding(self):
        binf = self.registry.create_format('binf', encoding='binary')

        @binf.reader(TestClass)
        def reader1(fh):
            self.assertIsInstance(fh, (io.BufferedReader, io.BufferedRandom))
            return TestClass(['woo'])

        @binf.reader(None)
        def reader2(fh):
            self.assertIsInstance(fh, (io.BufferedReader, io.BufferedRandom))
            yield TestClass(['woo'])

        instance = self.registry.read(self.fp1, format='binf', verify=False,
                                      into=TestClass)
        self.assertEqual(TestClass(['woo']), instance)

        gen = self.registry.read(self.fp1, format='binf', verify=False,
                                 into=None)
        self.assertEqual(TestClass(['woo']), next(gen))
        gen.close()

    def test_io_kwargs_passed(self):
        format1 = self.registry.create_format('format1')

        @format1.sniffer()
        def sniffer(fh):
            return True, {}

        @format1.reader(TestClass)
        def reader1(fh):
            self.assertEqual(fh.errors, 'replace')
            return TestClass(['woo'])

        @format1.reader(None)
        def reader1_gen(fh):
            self.assertEqual(fh.errors, 'replace')
            yield TestClass(['woo'])

        obj = self.registry.read(self.fp1, into=TestClass, errors='replace')
        self.assertEqual(obj, TestClass(['woo']))
        gen = self.registry.read(self.fp1, format='format1', errors='replace')
        self.assertEqual(next(gen), TestClass(['woo']))
        gen.close()

    def test_read_empty_file_gen_with_format(self):
        format1 = self.registry.create_format('format1')

        @format1.sniffer()
        def sniffer(fh):
            return True, {}

        @format1.reader(None)
        def reader1(fh):
            return
            yield

        with io.StringIO("") as fh:
            gen = self.registry.read(fh, format='format1')

        self.assertEqual(list(gen), [])


class TestWrite(RegistryTest):
    def test_writer_does_not_exist(self):
        fh = StringIO()
        with self.assertRaises(UnrecognizedFormatError) as cm:
            self.registry.write({}, format='not_a_format', into=fh)

        self.assertTrue('not_a_format' in str(cm.exception))
        self.assertTrue(str(fh) in str(cm.exception))
        fh.close()

    def test_writer_exists(self):
        format1 = self.registry.create_format('format1')

        obj = TestClass(['1', '2', '3', '4'])
        fh = StringIO()

        @format1.writer(TestClass)
        def writer(obj, fh):
            self.assertIsInstance(fh, io.TextIOBase)
            fh.write('\n'.join(obj.list))

        self.registry.write(obj, format='format1', into=fh)
        fh.seek(0)
        self.assertEqual("1\n2\n3\n4", fh.read())
        fh.close()

    def test_writer_exists_real_file(self):
        format1 = self.registry.create_format('format1')

        obj = TestClass(['1', '2', '3', '4'])
        fp = self.fp1

        @format1.writer(TestClass)
        def writer(obj, fh):
            self.assertIsInstance(fh, io.TextIOBase)
            fh.write('\n'.join(obj.list))

        self.registry.write(obj, format='format1', into=fp)

        with io.open(fp) as fh:
            self.assertEqual("1\n2\n3\n4", fh.read())

    def test_writer_passed_kwargs(self):
        format1 = self.registry.create_format('format1')

        @format1.reader(None)
        def reader(fh):
            yield

        @format1.writer(None)
        def writer(obj, fh, **kwargs):
            self.assertEqual(kwargs['passed'], True)

        generator = self.registry.get_reader('format1', None)([])
        self.registry.write(generator, format='format1',
                            into=StringIO(), passed=True)

    def test_that_encoding_is_used(self):
        format1 = self.registry.create_format('format1')

        obj = TestClass(['\u4f60\u597d\n'])  # Ni Hau
        fp = self.fp1

        @format1.writer(TestClass)
        def writer(obj, fh):
            fh.write(''.join(obj.list))
            self.assertEqual(self._expected_encoding, fh.encoding)

        self._expected_encoding = 'big5'
        self.registry.write(obj, format='format1', into=fp, encoding='big5')

        with io.open(fp, mode='rb') as fh:
            # This would have been b'\xe4\xbd\xa0\xe5\xa5\xbd\n' in utf8
            self.assertEqual(b'\xa7A\xa6n\n', fh.read())

    def test_non_default_encoding(self):
        format1 = self.registry.create_format('format1', encoding='big5')

        obj = TestClass(['\u4f60\u597d\n'])  # Ni Hau
        fp = self.fp1

        @format1.writer(TestClass)
        def writer(obj, fh):
            fh.write(''.join(obj.list))
            self.assertEqual(self._expected_encoding, fh.encoding)

        self._expected_encoding = 'big5'
        self.registry.write(obj, format='format1', into=fp)

        with io.open(fp, mode='rb') as fh:
            self.assertEqual(b'\xa7A\xa6n\n', fh.read())

        self._expected_encoding = 'utf8'
        self.registry.write(obj, format='format1', into=fp, encoding='utf8')

        with io.open(fp, mode='rb') as fh:
            self.assertEqual(b'\xe4\xbd\xa0\xe5\xa5\xbd\n', fh.read())

    def test_that_newline_is_used(self):
        format1 = self.registry.create_format('format1')

        obj = TestClass(['a\n', 'b\n', 'c\n'])
        fp = self.fp1

        @format1.writer(TestClass)
        def writer(obj, fh):
            fh.write(''.join(obj.list))

        self.registry.write(obj, format='format1', into=fp, newline='\r')

        with io.open(fp, mode='rb') as fh:
            self.assertEqual(b'a\rb\rc\r', fh.read())

    def test_non_default_newline(self):
        format1 = self.registry.create_format('format1', newline='\r')

        obj = TestClass(['a\n', 'b\n', 'c\n'])
        fp = self.fp1

        @format1.writer(TestClass)
        def writer(obj, fh):
            fh.write(''.join(obj.list))

        self.registry.write(obj, format='format1', into=fp)

        with io.open(fp, mode='rb') as fh:
            self.assertEqual(b'a\rb\rc\r', fh.read())

        self.registry.write(obj, format='format1', into=fp, newline='\n')

        with io.open(fp, mode='rb') as fh:
            self.assertEqual(b'a\nb\nc\n', fh.read())

    def test_file_sentinel_many(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO()

        @format1.writer(TestClass)
        def writer(obj, fh, extra=FileSentinel, other=2, extra_2=FileSentinel):
            extra.write('oh yeah...')
            extra_2.write('oh no...')

        self.registry.write(TestClass([]), format='format1', into=fh,
                            extra=self.fp1, extra_2=self.fp2)
        with open(self.fp1) as f1:
            self.assertEqual('oh yeah...', f1.read())

        with open(self.fp2) as f2:
            self.assertEqual('oh no...', f2.read())

        fh.close()

    def test_file_sentinel_converted_to_none(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO()

        @format1.writer(TestClass)
        def writer(obj, fh, extra=FileSentinel, other=2, extra_2=FileSentinel):
            self.assertIsNone(extra)
            self.assertIsNone(extra_2)

        self.registry.write(TestClass([]), format='format1', into=fh)

        fh.close()

    def test_file_sentinel_pass_none(self):
        format1 = self.registry.create_format('format1')

        fh = StringIO()

        @format1.writer(TestClass)
        def writer(obj, fh, extra=FileSentinel, other=2, extra_2=FileSentinel):
            self.assertIsNone(extra)
            self.assertIsNone(extra_2)

        self.registry.write(TestClass([]), format='format1', into=fh,
                            extra=None)

        fh.close()

    def test_write_with_illegal_encoding(self):
        binf = self.registry.create_format('binf', encoding='binary')
        textf = self.registry.create_format('textf', encoding=None)

        @binf.writer(TestClass)
        def writer(obj, fh):
            pass

        @textf.writer(TestClass)
        def writer2(obj, fh):
            pass

        with self.assertRaises(ValueError):
            self.registry.write(TestClass([]), into=self.fp1, format='binf',
                                encoding=None)

        with self.assertRaises(ValueError):
            self.registry.write(TestClass([]), into=self.fp1, format='textf',
                                encoding='binary')

    def test_write_binary_format(self):
        format1 = self.registry.create_format('format1', encoding='binary')

        obj = TestClass([b'a\n', b'b\n', b'c\n'])
        fp = self.fp1

        @format1.writer(TestClass)
        def writer(obj, fh):
            self.assertIsInstance(fh, (io.BufferedWriter, io.BufferedRandom))
            fh.write(b''.join(obj.list))

        self.registry.write(obj, format='format1', into=fp)

        with io.open(fp, mode='rb') as fh:
            self.assertEqual(b'a\nb\nc\n', fh.read())

    def test_io_kwargs_passed(self):
        format1 = self.registry.create_format('format1', encoding='ascii')

        obj = TestClass(['a\n', 'b\n', 'c\n'])
        fp = self.fp1
        f = io.BytesIO()

        @format1.writer(TestClass)
        def writer(obj, fh):
            iterator = iter(obj.list)
            fh.write(next(iterator))
            fh.flush()  # Flush should be a noop for bz2
            for l in iterator:
                fh.write(l)

        self.registry.write(obj, format='format1', into=fp, compression='bz2')
        self.registry.write(obj, format='format1', into=f, compression='bz2')
        expected = (
            b'BZh91AY&SY\x03\x89\x0c\xa6\x00\x00\x01\xc1\x00\x00\x108\x00 \x00'
            b'!\x9ah3M\x1c\xb7\x8b\xb9"\x9c(H\x01\xc4\x86S\x00')

        with io.open(fp, mode='rb') as fh:
            self.assertEqual(expected, fh.read())

        self.assertEqual(expected, f.getvalue())


class TestMonkeyPatch(RegistryTest):
    def setUp(self):
        super(TestMonkeyPatch, self).setUp()

        class UnassumingClass:
            pass

        class ClassWithDefault:
            default_write_format = 'favfmt'

        class NoMonkeySee:
            pass

        self.unassuming_class = UnassumingClass
        self.class_with_default = ClassWithDefault
        self.no_monkey_see = NoMonkeySee

    def test_no_readers_writers(self):
        self.registry.monkey_patch()
        self.assertFalse(hasattr(self.unassuming_class, 'read'))
        self.assertFalse(hasattr(self.unassuming_class, 'write'))
        self.assertFalse(hasattr(self.class_with_default, 'read'))
        self.assertFalse(hasattr(self.class_with_default, 'write'))

    def test_readers_only(self):
        favfmt = self.registry.create_format('favfmt')
        favfmt2 = self.registry.create_format('favfmt2')

        @favfmt.reader(self.unassuming_class)
        def fvfmt_to_unasumming_class(fh):
            return

        @favfmt.reader(None)
        def fvfmt_to_gen(fh):
            yield

        @favfmt2.reader(self.unassuming_class)
        def fvfmt2_to_unasumming_class(fh):
            return

        self.registry.monkey_patch()

        self.assertTrue(hasattr(self.unassuming_class, 'read'))
        self.assertFalse(hasattr(self.unassuming_class, 'write'))
        self.assertFalse(hasattr(self.class_with_default, 'read'))
        self.assertFalse(hasattr(self.class_with_default, 'write'))

        self.assertIn('favfmt', self.unassuming_class.read.__doc__)
        self.assertIn('favfmt2', self.unassuming_class.read.__doc__)

    def test_writers_only(self):
        favfmt = self.registry.create_format('favfmt')
        favfmt2 = self.registry.create_format('favfmt2')

        @favfmt.writer(self.class_with_default)
        def favfmt_writer(fh):
            pass

        @favfmt.writer(None)
        def gen_to_favfmt(fh):
            pass

        @favfmt2.writer(self.class_with_default)
        def favfmt2_writer(fh):
            pass

        self.registry.monkey_patch()

        self.assertFalse(hasattr(self.unassuming_class, 'read'))
        self.assertFalse(hasattr(self.unassuming_class, 'write'))
        self.assertFalse(hasattr(self.class_with_default, 'read'))
        self.assertTrue(hasattr(self.class_with_default, 'write'))

        self.assertIn('favfmt', self.class_with_default.write.__doc__)
        self.assertIn('favfmt2', self.class_with_default.write.__doc__)

    def test_writers_no_default_format(self):
        favfmt = self.registry.create_format('favfmt')
        favfmt2 = self.registry.create_format('favfmt2')

        @favfmt.writer(self.unassuming_class)
        def favfmt_writer(fh):
            pass

        @favfmt.writer(None)
        def gen_to_favfmt(fh):
            pass

        @favfmt2.writer(self.unassuming_class)
        def favfmt2_writer(fh):
            pass
        with self.assertRaises(NotImplementedError) as cm:
            self.registry.monkey_patch()

        self.assertIn('default_write_format', str(cm.exception))

    def test_readers_writers(self):
        favfmt = self.registry.create_format('favfmt')
        favfmt2 = self.registry.create_format('favfmt2')

        @favfmt.reader(self.unassuming_class)
        def fvfmt_to_unasumming_class(fh):
            return

        @favfmt.reader(self.class_with_default)
        def fvfmt_to_class_w_default(fh):
            return

        @favfmt.reader(None)
        def fvfmt_to_gen(fh):
            yield

        @favfmt2.reader(self.unassuming_class)
        def fvfmt2_to_unasumming_class(fh):
            return

        @favfmt2.reader(self.class_with_default)
        def fvfmt2_to_class_w_default(fh):
            return

        @favfmt.writer(self.class_with_default)
        def favfmt_writer(fh):
            pass

        @favfmt.writer(None)
        def gen_to_favfmt(fh):
            pass

        @favfmt2.writer(self.class_with_default)
        def favfmt2_writer(fh):
            pass

        @favfmt2.reader(self.no_monkey_see, monkey_patch=True)
        def favfmt2_to_monkey(fh):
            pass

        @favfmt2.writer(self.no_monkey_see, monkey_patch=False)
        def monkey_to_favfmt2(fh):
            pass

        self.registry.monkey_patch()

        self.assertTrue(hasattr(self.unassuming_class, 'read'))
        self.assertFalse(hasattr(self.unassuming_class, 'write'))

        self.assertTrue(hasattr(self.class_with_default, 'read'))
        self.assertTrue(hasattr(self.class_with_default, 'write'))

        self.assertTrue(hasattr(self.no_monkey_see, 'read'))
        self.assertFalse(hasattr(self.no_monkey_see, 'write'))

        self.assertIn('favfmt', self.unassuming_class.read.__doc__)
        self.assertIn('favfmt2', self.unassuming_class.read.__doc__)

        self.assertIn('favfmt', self.class_with_default.read.__doc__)
        self.assertIn('favfmt2', self.class_with_default.read.__doc__)

        self.assertIn('favfmt', self.class_with_default.write.__doc__)
        self.assertIn('favfmt2', self.class_with_default.write.__doc__)

        self.assertIn('favfmt2', self.no_monkey_see.read.__doc__)

    def test_read_kwargs_passed(self):
        favfmt = self.registry.create_format('favfmt')
        self.was_called = False

        @favfmt.sniffer()
        def fvfmt_sniffer(fh):
            return True, {}

        @favfmt.reader(self.class_with_default)
        def fvfmt_to_class_w_default(fh, **kwargs):
            self.assertEqual('a', kwargs['a'])
            self.assertEqual(123, kwargs['b'])
            self.was_called = True

        self.registry.monkey_patch()
        fh = StringIO('notempty')
        self.class_with_default.read(fh, a='a', b=123)

        self.assertTrue(self.was_called)
        fh.close()

    def test_write_kwargs_passed(self):
        favfmt = self.registry.create_format('favfmt')
        self.was_called = False

        @favfmt.writer(self.class_with_default)
        def favfmt_writer(obj, fh, **kwargs):
            self.assertEqual('a', kwargs['a'])
            self.assertEqual(123, kwargs['b'])
            self.was_called = True

        self.registry.monkey_patch()
        fh = StringIO()
        self.class_with_default().write(fh, a='a', b=123)

        self.assertTrue(self.was_called)
        fh.close()


class TestModuleFunctions(unittest.TestCase):

    def test_sniff_matches(self):
        exp = io_registry.sniff(['(a, b);'])
        result = sniff(['(a, b);'])
        self.assertEqual(exp, result)
        self.assertEqual('newick', exp[0])
        self.assertEqual({}, exp[1])

    def test_read_matches(self):
        input = ['>\n', 'ACGT\n']
        exp = io_registry.read(input, into=DNA)
        result = read(input, into=DNA)
        self.assertEqual(exp, result)
        self.assertEqual(exp, DNA('ACGT', metadata={'id': '',
                                                    'description': ''}))

    def test_write_matches(self):
        input = DNA('ACGT')
        exp = io_registry.write(input, format='fasta', into=[])
        result = write(input, format='fasta', into=[])
        self.assertEqual(exp, result)
        self.assertEqual(exp, ['>\n', 'ACGT\n'])

    def test_create_format_matches(self):
        with self.assertRaises(DuplicateRegistrationError):
            io_registry.create_format('fasta')

        with self.assertRaises(DuplicateRegistrationError):
            create_format('fasta')

if __name__ == '__main__':
    unittest.main()
