deb-python-taskflow/taskflow/tests/unit/test_utils.py

# -*- coding: utf-8 -*-

#    Copyright (C) 2012 Yahoo! Inc. 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.

import collections
import inspect
import random
import string
import time

import six
import testscenarios

from taskflow import test
from taskflow.utils import misc
from taskflow.utils import threading_utils


class CachedPropertyTest(test.TestCase):
    def test_attribute_caching(self):

        class A(object):
            def __init__(self):
                self.call_counter = 0

            @misc.cachedproperty
            def b(self):
                self.call_counter += 1
                return 'b'

        a = A()
        self.assertEqual('b', a.b)
        self.assertEqual('b', a.b)
        self.assertEqual(1, a.call_counter)

    def test_custom_property(self):

        class A(object):
            @misc.cachedproperty('_c')
            def b(self):
                return 'b'

        a = A()
        self.assertEqual('b', a.b)
        self.assertEqual('b', a._c)

    def test_no_delete(self):

        def try_del(a):
            del a.b

        class A(object):
            @misc.cachedproperty
            def b(self):
                return 'b'

        a = A()
        self.assertEqual('b', a.b)
        self.assertRaises(AttributeError, try_del, a)
        self.assertEqual('b', a.b)

    def test_set(self):

        def try_set(a):
            a.b = 'c'

        class A(object):
            @misc.cachedproperty
            def b(self):
                return 'b'

        a = A()
        self.assertEqual('b', a.b)
        self.assertRaises(AttributeError, try_set, a)
        self.assertEqual('b', a.b)

    def test_documented_property(self):

        class A(object):
            @misc.cachedproperty
            def b(self):
                """I like bees."""
                return 'b'

        self.assertEqual("I like bees.", inspect.getdoc(A.b))

    def test_undocumented_property(self):

        class A(object):
            @misc.cachedproperty
            def b(self):
                return 'b'

        self.assertEqual(None, inspect.getdoc(A.b))

    def test_threaded_access_property(self):
        called = collections.deque()

        class A(object):
            @misc.cachedproperty
            def b(self):
                called.append(1)
                # NOTE(harlowja): wait for a little and give some time for
                # another thread to potentially also get in this method to
                # also create the same property...
                time.sleep(random.random() * 0.5)
                return 'b'

        a = A()
        threads = []
        try:
            for _i in range(0, 20):
                t = threading_utils.daemon_thread(lambda: a.b)
                threads.append(t)
            for t in threads:
                t.start()
        finally:
            while threads:
                t = threads.pop()
                t.join()

        self.assertEqual(1, len(called))
        self.assertEqual('b', a.b)


class UriParseTest(test.TestCase):
    def test_parse(self):
        url = "zookeeper://192.168.0.1:2181/a/b/?c=d"
        parsed = misc.parse_uri(url)
        self.assertEqual('zookeeper', parsed.scheme)
        self.assertEqual(2181, parsed.port)
        self.assertEqual('192.168.0.1', parsed.hostname)
        self.assertEqual('', parsed.fragment)
        self.assertEqual('/a/b/', parsed.path)
        self.assertEqual({'c': 'd'}, parsed.params())

    def test_port_provided(self):
        url = "rabbitmq://www.yahoo.com:5672"
        parsed = misc.parse_uri(url)
        self.assertEqual('rabbitmq', parsed.scheme)
        self.assertEqual('www.yahoo.com', parsed.hostname)
        self.assertEqual(5672, parsed.port)
        self.assertEqual('', parsed.path)

    def test_ipv6_host(self):
        url = "rsync://[2001:db8:0:1]:873"
        parsed = misc.parse_uri(url)
        self.assertEqual('rsync', parsed.scheme)
        self.assertEqual('2001:db8:0:1', parsed.hostname)
        self.assertEqual(873, parsed.port)

    def test_user_password(self):
        url = "rsync://test:test_pw@www.yahoo.com:873"
        parsed = misc.parse_uri(url)
        self.assertEqual('test', parsed.username)
        self.assertEqual('test_pw', parsed.password)
        self.assertEqual('www.yahoo.com', parsed.hostname)

    def test_user(self):
        url = "rsync://test@www.yahoo.com:873"
        parsed = misc.parse_uri(url)
        self.assertEqual('test', parsed.username)
        self.assertEqual(None, parsed.password)


class TestSequenceMinus(test.TestCase):

    def test_simple_case(self):
        result = misc.sequence_minus([1, 2, 3, 4], [2, 3])
        self.assertEqual(result, [1, 4])

    def test_subtrahend_has_extra_elements(self):
        result = misc.sequence_minus([1, 2, 3, 4], [2, 3, 5, 7, 13])
        self.assertEqual(result, [1, 4])

    def test_some_items_are_equal(self):
        result = misc.sequence_minus([1, 1, 1, 1], [1, 1, 3])
        self.assertEqual(result, [1, 1])

    def test_equal_items_not_continious(self):
        result = misc.sequence_minus([1, 2, 3, 1], [1, 3])
        self.assertEqual(result, [2, 1])


class TestReversedEnumerate(testscenarios.TestWithScenarios, test.TestCase):
    scenarios = [
        ('ten', {'sample': [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]}),
        ('empty', {'sample': []}),
        ('negative', {'sample': [-1, -2, -3]}),
        ('one', {'sample': [1]}),
        ('abc', {'sample': ['a', 'b', 'c']}),
        ('ascii_letters', {'sample': list(string.ascii_letters)}),
    ]

    def test_sample_equivalence(self):
        expected = list(reversed(list(enumerate(self.sample))))
        actual = list(misc.reverse_enumerate(self.sample))
        self.assertEqual(expected, actual)


class TestCountdownIter(test.TestCase):
    def test_expected_count(self):
        upper = 100
        it = misc.countdown_iter(upper)
        items = []
        for i in it:
            self.assertEqual(upper, i)
            upper -= 1
            items.append(i)
        self.assertEqual(0, upper)
        self.assertEqual(100, len(items))

    def test_no_count(self):
        it = misc.countdown_iter(0)
        self.assertEqual(0, len(list(it)))
        it = misc.countdown_iter(-1)
        self.assertEqual(0, len(list(it)))

    def test_expected_count_custom_decr(self):
        upper = 100
        it = misc.countdown_iter(upper, decr=2)
        items = []
        for i in it:
            self.assertEqual(upper, i)
            upper -= 2
            items.append(i)
        self.assertEqual(0, upper)
        self.assertEqual(50, len(items))

    def test_invalid_decr(self):
        it = misc.countdown_iter(10, -1)
        self.assertRaises(ValueError, six.next, it)


class TestClamping(test.TestCase):
    def test_simple_clamp(self):
        result = misc.clamp(1.0, 2.0, 3.0)
        self.assertEqual(result, 2.0)
        result = misc.clamp(4.0, 2.0, 3.0)
        self.assertEqual(result, 3.0)
        result = misc.clamp(3.0, 4.0, 4.0)
        self.assertEqual(result, 4.0)

    def test_invalid_clamp(self):
        self.assertRaises(ValueError, misc.clamp, 0.0, 2.0, 1.0)

    def test_clamped_callback(self):
        calls = []

        def on_clamped():
            calls.append(True)

        misc.clamp(-1, 0.0, 1.0, on_clamped=on_clamped)
        self.assertEqual(1, len(calls))
        calls.pop()

        misc.clamp(0.0, 0.0, 1.0, on_clamped=on_clamped)
        self.assertEqual(0, len(calls))

        misc.clamp(2, 0.0, 1.0, on_clamped=on_clamped)
        self.assertEqual(1, len(calls))