#
# Licensed to the Apache Software Foundation (ASF) under one or more
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# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
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"""Tests for decorators module."""

# pytype: skip-file

from __future__ import absolute_import

import re
import sys
import unittest

import future.tests.base  # pylint: disable=unused-import

from apache_beam.typehints import Any
from apache_beam.typehints import List
from apache_beam.typehints import WithTypeHints
from apache_beam.typehints import decorators
from apache_beam.typehints import typehints


class IOTypeHintsTest(unittest.TestCase):
  def test_get_signature(self):
    # Basic coverage only to make sure function works in Py2 and Py3.
    def fn(a, b=1, *c, **d):
      return a, b, c, d

    s = decorators.get_signature(fn)
    self.assertListEqual(list(s.parameters), ['a', 'b', 'c', 'd'])

  def test_get_signature_builtin(self):
    # Tests a builtin function for 3.7+ and fallback result for older versions.
    s = decorators.get_signature(list)
    if sys.version_info < (3, 7):
      self.assertListEqual(
          list(s.parameters),
          ['_', '__unknown__varargs', '__unknown__keywords'])
    else:
      self.assertListEqual(list(s.parameters), ['iterable'])
    self.assertEqual(s.return_annotation, List[Any])

  def test_from_callable_without_annotations(self):
    # Python 2 doesn't support annotations. See decorators_test_py3.py for that.
    def fn(a, b=None, *args, **kwargs):
      return a, b, args, kwargs

    th = decorators.IOTypeHints.from_callable(fn)
    self.assertIsNone(th)

  def test_from_callable_builtin(self):
    th = decorators.IOTypeHints.from_callable(len)
    self.assertIsNone(th)

  def test_from_callable_method_descriptor(self):
    # from_callable() injects an annotation in this special type of builtin.
    th = decorators.IOTypeHints.from_callable(str.strip)
    if sys.version_info >= (3, 7):
      self.assertEqual(th.input_types, ((str, Any), {}))
    else:
      self.assertEqual(
          th.input_types,
          ((str, decorators._ANY_VAR_POSITIONAL), {
              '__unknown__keywords': decorators._ANY_VAR_KEYWORD
          }))
    self.assertEqual(th.output_types, ((Any, ), {}))

  def test_strip_iterable_not_simple_output_noop(self):
    th = decorators.IOTypeHints(
        input_types=None, output_types=((int, str), {}), origin=[])
    th = th.strip_iterable()
    self.assertEqual(((int, str), {}), th.output_types)

  def _test_strip_iterable(self, before, expected_after):
    th = decorators.IOTypeHints(
        input_types=None, output_types=((before, ), {}), origin=[])
    after = th.strip_iterable()
    self.assertEqual(((expected_after, ), {}), after.output_types)

  def _test_strip_iterable_fail(self, before):
    with self.assertRaisesRegex(ValueError, r'not iterable'):
      self._test_strip_iterable(before, None)

  def test_strip_iterable(self):
    self._test_strip_iterable(None, None)
    self._test_strip_iterable(typehints.Any, typehints.Any)
    self._test_strip_iterable(typehints.Iterable[str], str)
    self._test_strip_iterable(typehints.List[str], str)
    self._test_strip_iterable(typehints.Iterator[str], str)
    self._test_strip_iterable(typehints.Generator[str], str)
    self._test_strip_iterable(typehints.Tuple[str], str)
    self._test_strip_iterable(
        typehints.Tuple[str, int], typehints.Union[str, int])
    self._test_strip_iterable(typehints.Tuple[str, ...], str)
    self._test_strip_iterable(typehints.KV[str, int], typehints.Union[str, int])
    self._test_strip_iterable(typehints.Set[str], str)

    self._test_strip_iterable_fail(typehints.Union[str, int])
    self._test_strip_iterable_fail(typehints.Optional[str])
    self._test_strip_iterable_fail(typehints.WindowedValue[str])  # type: ignore[misc]
    self._test_strip_iterable_fail(typehints.Dict[str, int])

  def test_make_traceback(self):
    origin = ''.join(
        decorators.IOTypeHints.empty().with_input_types(str).origin)
    self.assertRegex(origin, __name__)
    # TODO: use self.assertNotRegex once py2 support is removed.
    self.assertIsNone(re.search(r'\b_make_traceback', origin), msg=origin)

  def test_origin(self):
    th = decorators.IOTypeHints.empty()
    self.assertListEqual([], th.origin)
    th = th.with_input_types(str)
    self.assertRegex(th.debug_str(), r'with_input_types')
    th = th.with_output_types(str)
    self.assertRegex(th.debug_str(), r'(?s)with_output_types.*with_input_types')

    th = decorators.IOTypeHints.empty().with_output_types(str)
    th2 = decorators.IOTypeHints.empty().with_input_types(int)
    th = th.with_defaults(th2)
    self.assertRegex(th.debug_str(), r'(?s)based on:.*\'str\'.*and:.*\'int\'')

  def test_with_defaults_noop_does_not_grow_origin(self):
    th = decorators.IOTypeHints.empty()
    expected_id = id(th)
    th = th.with_defaults(None)
    self.assertEqual(expected_id, id(th))
    th = th.with_defaults(decorators.IOTypeHints.empty())
    self.assertEqual(expected_id, id(th))

    th = th.with_input_types(str)
    expected_id = id(th)
    th = th.with_defaults(th)
    self.assertEqual(expected_id, id(th))

    th2 = th.with_output_types(int)
    th = th.with_defaults(th2)
    self.assertNotEqual(expected_id, id(th))


class WithTypeHintsTest(unittest.TestCase):
  def test_get_type_hints_no_settings(self):
    class Base(WithTypeHints):
      pass

    th = Base().get_type_hints()
    self.assertEqual(th.input_types, None)
    self.assertEqual(th.output_types, None)

  def test_get_type_hints_class_decorators(self):
    @decorators.with_input_types(int, str)
    @decorators.with_output_types(int)
    class Base(WithTypeHints):
      pass

    th = Base().get_type_hints()
    self.assertEqual(th.input_types, ((int, str), {}))
    self.assertEqual(th.output_types, ((int, ), {}))

  def test_get_type_hints_class_defaults(self):
    class Base(WithTypeHints):
      def default_type_hints(self):
        return decorators.IOTypeHints(
            input_types=((int, str), {}), output_types=((int, ), {}), origin=[])

    th = Base().get_type_hints()
    self.assertEqual(th.input_types, ((int, str), {}))
    self.assertEqual(th.output_types, ((int, ), {}))

  def test_get_type_hints_precedence_defaults_over_decorators(self):
    @decorators.with_input_types(int)
    @decorators.with_output_types(str)
    class Base(WithTypeHints):
      def default_type_hints(self):
        return decorators.IOTypeHints(
            input_types=((float, ), {}), output_types=None, origin=[])

    th = Base().get_type_hints()
    self.assertEqual(th.input_types, ((float, ), {}))
    self.assertEqual(th.output_types, ((str, ), {}))

  def test_get_type_hints_precedence_instance_over_defaults(self):
    class Base(WithTypeHints):
      def default_type_hints(self):
        return decorators.IOTypeHints(
            input_types=((float, ), {}), output_types=((str, ), {}), origin=[])

    th = Base().with_input_types(int).get_type_hints()
    self.assertEqual(th.input_types, ((int, ), {}))
    self.assertEqual(th.output_types, ((str, ), {}))

  def test_inherits_does_not_modify(self):
    # See BEAM-8629.
    @decorators.with_output_types(int)
    class Subclass(WithTypeHints):
      def __init__(self):
        pass  # intentionally avoiding super call

    # These should be equal, but not the same object lest mutating the instance
    # mutates the class.
    self.assertIsNot(
        Subclass()._get_or_create_type_hints(), Subclass._type_hints)
    self.assertEqual(Subclass().get_type_hints(), Subclass._type_hints)
    self.assertNotEqual(
        Subclass().with_input_types(str)._type_hints, Subclass._type_hints)


class DecoratorsTest(unittest.TestCase):
  def tearDown(self):
    decorators._disable_from_callable = False

  def test_disable_type_annotations(self):
    self.assertFalse(decorators._disable_from_callable)
    decorators.disable_type_annotations()
    self.assertTrue(decorators._disable_from_callable)


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