rstdocs/examples/iterqueue_test.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf8 -*-
   3
   4 # iterqueue_test.py
   5 # *****************
   6 # Test the iterator wrappers from iterqueue.py
   7 # ============================================
   8 #
   9 # .. contents::
  10 #
  11 # ::
  12
  13 import sys, itertools
  14 import iterqueue
  15 from iterqueue import *
  16
  17 # Get and sort the wrapper classes
  18 # --------------------------------
  19 #
  20 # List all iterator wrapper objects::
  21
  22 wrappers = [obj for obj in iterqueue.__dict__.values()
  23             if is_iterator_wrapper(obj)]
  24 # print "\n".join(repr(wrapper) for wrapper in wrappers)
  25
  26 # List iterator wrappers that provide a `peek` method::
  27
  28 peekables = [obj for obj in wrappers if is_peekable(obj)]
  29 # print "Peekables"
  30 # print "\n".join(repr(peekable) for peekable in peekables)
  31
  32 # List iterator wrappers that provide a `push` method::
  33
  34 pushables = [obj for obj in wrappers if is_pushable(obj)]
  35 # print "Pushables"
  36 # print "\n".join(repr(pushable) for pushable in pushables)
  37
  38 # List iterator wrappers that provide a test for "values available"::
  39
  40 state_reporters = [obj for obj in wrappers if is_state_reporting(obj)]
  41 # print "State Reporters"
  42 # print "\n".join(repr(state_reporter) for state_reporter in state_reporters)
  43
  44 # List iterator wrappers that implement the "queue" methods::
  45
  46 iqueues = [obj for obj in wrappers if is_iterator_queue(obj)]
  47 # print "Iterator Queues"
  48 # print "\n".join(repr(iqueue) for iqueue in iqueues)
  49
  50
  51 # Test Wrappers
  52 # -------------
  53 #
  54 # Test the basic iterator features of an iterator wrapper. ::
  55
  56 class Test_Wrappers:
  57     """Test the wrapping of iterator wrappers"""
  58     def wrap_ok(self, wrapper, base):
  59         """iterating over the wrapper should return the same
  60         as iterating over base
  61         """
  62         print wrapper
  63         assert list(wrapper(base)) == list(base)
  64         assert [i for i in wrapper(base)] == [i for i in base]
  65
  66     def test_wrappers(self, base=xrange(3)):
  67         for wrapper in wrappers:
  68             yield self.wrap_ok, wrapper, base
  69
  70
  71 # Test Peekables
  72 # --------------
  73 #
  74 # ::
  75
  76 class Test_Peekables:
  77     """Test the peek method of iterator wrappers"""
  78     def peek_ok(self, wrapper, base):
  79         """peek() should return next value but not advance the iterator"""
  80         print wrapper
  81         print wrapper.peek
  82         it = wrapper(base)
  83         it.peek()
  84         first = it.peek()
  85         print first
  86         assert first == 0
  87         # peek() must not "use up" values
  88         result = list(it)
  89         print result
  90         assert result == list(base)
  91
  92     def test_peekables(self, base=xrange(3)):
  93         """Test generator for peekable iterator wrappers"""
  94         for wrapper in peekables:
  95             yield self.peek_ok, wrapper, base
  96
  97 # Test Pushables
  98 # --------------
  99 #
 100 # ::
 101
 102 class Test_Pushables:
 103     """Test the push method of iterator wrappers"""
 104
 105     def push_ok(self, wrapper, base):
 106         """push(value) shall prepend `value` to iterator"""
 107         print wrapper.push
 108         it = wrapper(base)
 109         it.push(9)
 110         result = list(it)
 111         print result
 112         assert result == [9] + list(base)
 113
 114     def push_while_iterating_ok(self, wrapper):
 115         """push shall work even in an iteration loop"""
 116         print wrapper
 117         it = wrapper(xrange(3))
 118         result = []
 119         for i in it:
 120             if i == 1:
 121                 it.push("xx")
 122             result.append(i)
 123         assert result == [0, 1, 'xx', 2]
 124
 125     def test_pushables(self, base=xrange(3)):
 126         """Test generator for pushable iterator wrappers"""
 127         for wrapper in pushables:
 128             if not hasattr(wrapper, "push"):
 129                 wrapper.push = wrapper.appendleft
 130             yield self.push_ok, wrapper, base
 131             yield self.push_while_iterating_ok, wrapper
 132
 133
 134 # Test Iterator Queue
 135 # -------------------
 136 #
 137 # ::
 138
 139 class TestIteratorQueue:
 140     """Test the queueing methods of iterator queues"""
 141     #
 142     def extend_ok(self, wrapper, base):
 143         """extend(iterable) shall append `iterable` to iterator"""
 144         print wrapper
 145         it = wrapper(base)
 146         it.extend([9])
 147         assert list(it) == list(base) + [9]
 148
 149     def extendleft_ok(self, wrapper, base):
 150         """extendleft(iterable) shall prepend `iterable` to iterator"""
 151         print wrapper
 152         it = wrapper(base)
 153         it.extendleft([9])
 154         result = [i for i in it]
 155         print result
 156         assert result == [9] + list(base)
 157
 158     def append_ok(self, wrapper, base):
 159         """append(value) shall append `value` to iterator"""
 160         print wrapper
 161         it = wrapper(base)
 162         it.append(9)
 163         result = list(it)
 164         print result
 165         assert result == list(base) + [9]
 166
 167     def test_iqueues(self, base=xrange(3)):
 168         """Test generator for iterator-queue wrappers"""
 169         for wrapper in iqueues:
 170             yield self.extend_ok, wrapper, base
 171             yield self.extendleft_ok, wrapper, base
 172             yield self.append_ok, wrapper, base
 173
 174
 175 # Test State Reporters
 176 # --------------------
 177 #
 178 # ::
 179
 180 class Test_StateReporters:
 181     """Test the state reporting when converted to bool"""
 182     def bool_ok(self, wrapper):
 183         """Empty iterator should evaluate to False
 184            Non-empty iterator should evaluate to True
 185            the evaluation should not advance the iterator
 186            """
 187         base = xrange(3) # make sure it is not empty!
 188         it0 = wrapper([])
 189         assert bool(it0) == False
 190         assert list(it0) == []
 191         it1 = wrapper(base)
 192         assert bool(it1) == True
 193         assert list(it1) == list(base)
 194         assert bool(wrapper(iter([]))) == False
 195         assert bool(wrapper(iter([1]))) == True
 196
 197     def test_iqueues(self):
 198         """Test generator for iterator-queue wrappers"""
 199         for wrapper in state_reporters:
 200             yield self.bool_ok, wrapper
 201
 202
 203 if __name__ == "__main__":
 204     import nose
 205     # this doesnot show any effect :-(
 206     nose.configure(["test.py", "--detailed-errors"])
 207     nose.runmodule() # requires nose 0.9.1