sdks/python/apache_beam/internal/pickler_test.py

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#    http://www.apache.org/licenses/LICENSE-2.0
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"""Unit tests for the pickler module."""

from __future__ import absolute_import

import sys
import types
import unittest

from apache_beam.internal import module_test
from apache_beam.internal.pickler import dumps
from apache_beam.internal.pickler import loads


class PicklerTest(unittest.TestCase):

  NO_MAPPINGPROXYTYPE = not hasattr(types, "MappingProxyType")

  def test_basics(self):
    self.assertEqual([1, 'a', (u'z',)], loads(dumps([1, 'a', (u'z',)])))
    fun = lambda x: 'xyz-%s' % x
    self.assertEqual('xyz-abc', loads(dumps(fun))('abc'))

  def test_lambda_with_globals(self):
    """Tests that the globals of a function are preserved."""

    # The point of the test is that the lambda being called after unpickling
    # relies on having the re module being loaded.
    self.assertEqual(
        ['abc', 'def'],
        loads(dumps(module_test.get_lambda_with_globals()))('abc def'))

  def test_lambda_with_main_globals(self):
    self.assertEqual(unittest, loads(dumps(lambda: unittest))())

  def test_lambda_with_closure(self):
    """Tests that the closure of a function is preserved."""
    self.assertEqual(
        'closure: abc',
        loads(dumps(module_test.get_lambda_with_closure('abc')))())

  def test_class(self):
    """Tests that a class object is pickled correctly."""
    self.assertEqual(
        ['abc', 'def'],
        loads(dumps(module_test.Xyz))().foo('abc def'))

  def test_object(self):
    """Tests that a class instance is pickled correctly."""
    self.assertEqual(
        ['abc', 'def'],
        loads(dumps(module_test.XYZ_OBJECT)).foo('abc def'))

  def test_nested_class(self):
    """Tests that a nested class object is pickled correctly."""
    self.assertEqual(
        'X:abc',
        loads(dumps(module_test.TopClass.NestedClass('abc'))).datum)
    self.assertEqual(
        'Y:abc',
        loads(dumps(module_test.TopClass.MiddleClass.NestedClass('abc'))).datum)

  def test_dynamic_class(self):
    """Tests that a nested class object is pickled correctly."""
    self.assertEqual(
        'Z:abc',
        loads(dumps(module_test.create_class('abc'))).get())

  def test_generators(self):
    with self.assertRaises(TypeError):
      dumps((_ for _ in range(10)))

  def test_recursive_class(self):
    self.assertEqual('RecursiveClass:abc',
                     loads(dumps(module_test.RecursiveClass('abc').datum)))

  @unittest.skipIf(NO_MAPPINGPROXYTYPE, 'test if MappingProxyType introduced')
  def test_dump_and_load_mapping_proxy(self):
    self.assertEqual(
        'def', loads(dumps(types.MappingProxyType({'abc': 'def'})))['abc'])
    self.assertEqual(types.MappingProxyType,
                     type(loads(dumps(types.MappingProxyType({})))))

  # pylint: disable=exec-used
  @unittest.skipIf(sys.version_info < (3, 7), 'Python 3.7 or above only')
  def test_dataclass(self):
    exec('''
from apache_beam.internal.module_test import DataClass
self.assertEqual(DataClass(datum='abc'), loads(dumps(DataClass(datum='abc'))))
    ''')


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