cpython/Lib/test/test_StringIO.py

128 lines
3.6 KiB
Python

# Tests StringIO and cStringIO
import sys
import unittest
import io
from test import test_support
class TestGenericStringIO:
# use a class variable CLASS to define which class is being tested
CLASS = None
# Line of data to test as string
_line = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!'
# Constructor to use for the test data (._line is passed to this
# constructor)
constructor = str
def setUp(self):
self._line = self.constructor(self._line)
self._lines = self.constructor((self._line + '\n') * 5)
self._fp = self.CLASS(self._lines)
def test_reads(self):
eq = self.assertEqual
self.assertRaises(TypeError, self._fp.seek)
eq(self._fp.read(10), self._line[:10])
eq(self._fp.readline(), self._line[10:] + '\n')
eq(len(self._fp.readlines(60)), 2)
def test_writes(self):
f = self.CLASS()
self.assertRaises(TypeError, f.seek)
f.write(self._line[:6])
f.seek(3)
f.write(self._line[20:26])
f.write(self._line[52])
self.assertEqual(f.getvalue(), 'abcuvwxyz!')
def test_writelines(self):
f = self.CLASS()
f.writelines([self._line[0], self._line[1], self._line[2]])
f.seek(0)
self.assertEqual(f.getvalue(), 'abc')
def test_writelines_error(self):
def errorGen():
yield 'a'
raise KeyboardInterrupt()
f = self.CLASS()
self.assertRaises(KeyboardInterrupt, f.writelines, errorGen())
def test_truncate(self):
eq = self.assertEqual
f = self.CLASS()
f.write(self._lines)
f.seek(10)
f.truncate()
eq(f.getvalue(), 'abcdefghij')
f.truncate(5)
eq(f.getvalue(), 'abcde')
f.write('xyz')
eq(f.getvalue(), 'abcdexyz')
self.assertRaises(ValueError, f.truncate, -1)
f.close()
self.assertRaises(ValueError, f.write, 'frobnitz')
def test_closed_flag(self):
f = self.CLASS()
self.assertEqual(f.closed, False)
f.close()
self.assertEqual(f.closed, True)
f = self.CLASS(self.constructor("abc"))
self.assertEqual(f.closed, False)
f.close()
self.assertEqual(f.closed, True)
def test_isatty(self):
f = self.CLASS()
self.assertRaises(TypeError, f.isatty, None)
self.assertEqual(f.isatty(), False)
f.close()
self.assertRaises(ValueError, f.isatty)
def test_iterator(self):
eq = self.assertEqual
unless = self.failUnless
eq(iter(self._fp), self._fp)
# Does this object support the iteration protocol?
unless(hasattr(self._fp, '__iter__'))
unless(hasattr(self._fp, '__next__'))
i = 0
for line in self._fp:
eq(line, self._line + '\n')
i += 1
eq(i, 5)
self._fp.close()
self.assertRaises(StopIteration, next, self._fp)
class TestioStringIO(TestGenericStringIO, unittest.TestCase):
CLASS = io.StringIO
def test_unicode(self):
if not test_support.have_unicode: return
# The StringIO module also supports concatenating Unicode
# snippets to larger Unicode strings. This is tested by this
# method. Note that cStringIO does not support this extension.
f = self.CLASS()
f.write(self._line[:6])
f.seek(3)
f.write(str(self._line[20:26]))
f.write(str(self._line[52]))
s = f.getvalue()
self.assertEqual(s, str('abcuvwxyz!'))
self.assertEqual(type(s), str)
def test_main():
test_support.run_unittest(TestioStringIO)
if __name__ == '__main__':
test_main()