Lib/test/test_univnewlines.py

   1 # Tests universal newline support for both reading and parsing files.
   2
   3 # NOTE: this file tests the new `io` library backported from Python 3.x.
   4 # Similar tests for the builtin file object can be found in test_univnewlines2k.py.
   5
   6 from __future__ import print_function
   7 from __future__ import unicode_literals
   8
   9 import io
  10 import _pyio as pyio
  11 import unittest
  12 import os
  13 import sys
  14 from test import test_support as support
  15
  16 if not hasattr(sys.stdin, 'newlines'):
  17     raise unittest.SkipTest(
  18         "This Python does not have universal newline support")
  19
  20 FATX = 'x' * (2**14)
  21
  22 DATA_TEMPLATE = [
  23     "line1=1",
  24     "line2='this is a very long line designed to go past any default " +
  25         "buffer limits that exist in io.py but we also want to test " +
  26         "the uncommon case, naturally.'",
  27     "def line3():pass",
  28     "line4 = '%s'" % FATX,
  29     ]
  30
  31 DATA_LF = "\n".join(DATA_TEMPLATE) + "\n"
  32 DATA_CR = "\r".join(DATA_TEMPLATE) + "\r"
  33 DATA_CRLF = "\r\n".join(DATA_TEMPLATE) + "\r\n"
  34
  35 # Note that DATA_MIXED also tests the ability to recognize a lone \r
  36 # before end-of-file.
  37 DATA_MIXED = "\n".join(DATA_TEMPLATE) + "\r"
  38 DATA_SPLIT = [x + "\n" for x in DATA_TEMPLATE]
  39
  40 class TestGenericUnivNewlines(unittest.TestCase):
  41     # use a class variable DATA to define the data to write to the file
  42     # and a class variable NEWLINE to set the expected newlines value
  43     READMODE = 'r'
  44     WRITEMODE = 'wb'
  45
  46     def setUp(self):
  47         data = self.DATA
  48         if "b" in self.WRITEMODE:
  49             data = data.encode("ascii")
  50         with self.open(support.TESTFN, self.WRITEMODE) as fp:
  51             fp.write(data)
  52
  53     def tearDown(self):
  54         try:
  55             os.unlink(support.TESTFN)
  56         except:
  57             pass
  58
  59     def test_read(self):
  60         with self.open(support.TESTFN, self.READMODE) as fp:
  61             data = fp.read()
  62         self.assertEqual(data, DATA_LF)
  63         self.assertEqual(set(fp.newlines), set(self.NEWLINE))
  64
  65     def test_readlines(self):
  66         with self.open(support.TESTFN, self.READMODE) as fp:
  67             data = fp.readlines()
  68         self.assertEqual(data, DATA_SPLIT)
  69         self.assertEqual(set(fp.newlines), set(self.NEWLINE))
  70
  71     def test_readline(self):
  72         with self.open(support.TESTFN, self.READMODE) as fp:
  73             data = []
  74             d = fp.readline()
  75             while d:
  76                 data.append(d)
  77                 d = fp.readline()
  78         self.assertEqual(data, DATA_SPLIT)
  79         self.assertEqual(set(fp.newlines), set(self.NEWLINE))
  80
  81     def test_seek(self):
  82         with self.open(support.TESTFN, self.READMODE) as fp:
  83             fp.readline()
  84             pos = fp.tell()
  85             data = fp.readlines()
  86             self.assertEqual(data, DATA_SPLIT[1:])
  87             fp.seek(pos)
  88             data = fp.readlines()
  89         self.assertEqual(data, DATA_SPLIT[1:])
  90
  91
  92 class TestCRNewlines(TestGenericUnivNewlines):
  93     NEWLINE = '\r'
  94     DATA = DATA_CR
  95
  96 class TestLFNewlines(TestGenericUnivNewlines):
  97     NEWLINE = '\n'
  98     DATA = DATA_LF
  99
 100 class TestCRLFNewlines(TestGenericUnivNewlines):
 101     NEWLINE = '\r\n'
 102     DATA = DATA_CRLF
 103
 104     def test_tell(self):
 105         with self.open(support.TESTFN, self.READMODE) as fp:
 106             self.assertEqual(repr(fp.newlines), repr(None))
 107             data = fp.readline()
 108             pos = fp.tell()
 109         self.assertEqual(repr(fp.newlines), repr(self.NEWLINE))
 110
 111 class TestMixedNewlines(TestGenericUnivNewlines):
 112     NEWLINE = ('\r', '\n')
 113     DATA = DATA_MIXED
 114
 115
 116 def test_main():
 117     base_tests = (TestCRNewlines,
 118                   TestLFNewlines,
 119                   TestCRLFNewlines,
 120                   TestMixedNewlines)
 121     tests = []
 122     # Test the C and Python implementations.
 123     for test in base_tests:
 124         class CTest(test):
 125             open = io.open
 126         CTest.__name__ = str("C" + test.__name__)
 127         class PyTest(test):
 128             open = staticmethod(pyio.open)
 129         PyTest.__name__ = str("Py" + test.__name__)
 130         tests.append(CTest)
 131         tests.append(PyTest)
 132     support.run_unittest(*tests)
 133
 134 if __name__ == '__main__':
 135     test_main()