# Copyright 2017 The TensorFlow Authors. All Rights Reserved.
#
# Licensed 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.
# See the License for the specific language governing permissions and
# limitations under the License.
# ==============================================================================
"""Tests for exceptions module."""

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

from tensorflow.python.autograph.operators import exceptions
from tensorflow.python.framework import constant_op
from tensorflow.python.framework import errors_impl
from tensorflow.python.platform import test


class ExceptionsTest(test.TestCase):

  def test_assert_tf_untriggered(self):
    with self.cached_session() as sess:
      t = exceptions.assert_stmt(
          constant_op.constant(True), lambda: constant_op.constant('ignored'))
      sess.run(t)

  def test_assert_tf_triggered(self):
    with self.cached_session() as sess:
      t = exceptions.assert_stmt(
          constant_op.constant(False),
          lambda: constant_op.constant('test message'))

      with self.assertRaisesRegexp(errors_impl.InvalidArgumentError,
                                   'test message'):
        sess.run(t)

  def test_assert_tf_multiple_printed_values(self):
    two_tensors = [
        constant_op.constant('test message'),
        constant_op.constant('another message')
    ]
    with self.cached_session() as sess:
      t = exceptions.assert_stmt(
          constant_op.constant(False), lambda: two_tensors)

      with self.assertRaisesRegexp(errors_impl.InvalidArgumentError,
                                   'test message.*another message'):
        sess.run(t)

  def test_assert_python_untriggered(self):
    side_effect_trace = []

    def expression_with_side_effects():
      side_effect_trace.append(object())
      return 'test message'

    exceptions.assert_stmt(True, expression_with_side_effects)

    self.assertListEqual(side_effect_trace, [])

  def test_assert_python_triggered(self):
    if not __debug__:
      # Python assertions only be tested when in debug mode.
      return

    side_effect_trace = []
    tracer = object()

    def expression_with_side_effects():
      side_effect_trace.append(tracer)
      return 'test message'

    with self.assertRaisesRegexp(AssertionError, 'test message'):
      exceptions.assert_stmt(False, expression_with_side_effects)
    self.assertListEqual(side_effect_trace, [tracer])


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