#
# 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
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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#

import logging
import unittest

import apache_beam as beam
from apache_beam.runners.trivial_runner import TrivialRunner
from apache_beam.testing.util import assert_that
from apache_beam.testing.util import equal_to


class TrivialRunnerTest(unittest.TestCase):
  def test_trivial(self):
    # The most trivial pipeline, to ensure at least something is working.
    # (Notably avoids the non-trivial complexity within assert_that.)
    with beam.Pipeline(runner=TrivialRunner()) as p:
      _ = p | beam.Impulse()

  def test_assert_that(self):
    # If this fails, the other tests may be vacuous.
    with self.assertRaisesRegex(Exception, 'Failed assert'):
      with beam.Pipeline(runner=TrivialRunner()) as p:
        assert_that(p | beam.Impulse(), equal_to(['a']))

  def test_impulse(self):
    with beam.Pipeline(runner=TrivialRunner()) as p:
      assert_that(p | beam.Impulse(), equal_to([b'']))

  def test_create(self):
    with beam.Pipeline(runner=TrivialRunner()) as p:
      assert_that(p | beam.Create(['a', 'b']), equal_to(['a', 'b']))

  def test_flatten(self):
    with beam.Pipeline(runner=TrivialRunner()) as p:
      # Disabling reshuffle here (and elsewhere) just to give a simpler graph
      # for debugging.
      ab = p | 'AB' >> beam.Create(['a', 'b'], reshuffle=False)
      c = p | 'C' >> beam.Create(['c'], reshuffle=False)
      assert_that((ab, c, c) | beam.Flatten(), equal_to(['a', 'b', 'c', 'c']))

  def test_map(self):
    with beam.Pipeline(runner=TrivialRunner()) as p:
      assert_that(
          p | beam.Create(['a', 'b'], reshuffle=False) | beam.Map(str.upper),
          equal_to(['A', 'B']))

  def test_gbk(self):
    with beam.Pipeline(runner=TrivialRunner()) as p:
      result = (
          p
          | beam.Create([('a', 1), ('b', 2), ('b', 3)], reshuffle=False)
          | beam.GroupByKey()
          | beam.MapTuple(lambda k, vs: (k, sorted(vs))))
      assert_that(result, equal_to([('a', [1]), ('b', [2, 3])]))


if __name__ == '__main__':
  logging.getLogger().setLevel(logging.INFO)
  unittest.main()