summaryrefslogtreecommitdiffstats
path: root/Lib/test/test_file.py
blob: a57ab4315838088fbaa2fb45d7a03dfbdf592245 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
import sys
import os
import unittest
from array import array
from weakref import proxy

from test.test_support import TESTFN, findfile, run_unittest
from UserList import UserList

class AutoFileTests(unittest.TestCase):
    # file tests for which a test file is automatically set up

    def setUp(self):
        self.f = open(TESTFN, 'wb')

    def tearDown(self):
        if self.f:
            self.f.close()
        os.remove(TESTFN)

    def testWeakRefs(self):
        # verify weak references
        p = proxy(self.f)
        p.write('teststring')
        self.assertEquals(self.f.tell(), p.tell())
        self.f.close()
        self.f = None
        self.assertRaises(ReferenceError, getattr, p, 'tell')

    def testAttributes(self):
        # verify expected attributes exist
        f = self.f
        f.name     # merely shouldn't blow up
        f.mode     # ditto
        f.closed   # ditto

        # verify the others aren't
        for attr in 'name', 'mode', 'closed':
            self.assertRaises((AttributeError, TypeError), setattr, f, attr, 'oops')

    def testReadinto(self):
        # verify readinto
        self.f.write('12')
        self.f.close()
        a = array('c', 'x'*10)
        self.f = open(TESTFN, 'rb')
        n = self.f.readinto(a)
        self.assertEquals('12', a.tostring()[:n])

    def testReadinto_text(self):
        # verify readinto refuses text files
        a = array('c', 'x'*10)
        self.f.close()
        self.f = open(TESTFN, 'r')
        self.assertRaises(TypeError, self.f.readinto, a)

    def testWritelinesUserList(self):
        # verify writelines with instance sequence
        l = UserList(['1', '2'])
        self.f.writelines(l)
        self.f.close()
        self.f = open(TESTFN, 'rb')
        buf = self.f.read()
        self.assertEquals(buf, '12')

    def testWritelinesIntegers(self):
        # verify writelines with integers
        self.assertRaises(TypeError, self.f.writelines, [1, 2, 3])

    def testWritelinesIntegersUserList(self):
        # verify writelines with integers in UserList
        l = UserList([1,2,3])
        self.assertRaises(TypeError, self.f.writelines, l)

    def testWritelinesNonString(self):
        # verify writelines with non-string object
        class NonString:
            pass

        self.assertRaises(TypeError, self.f.writelines,
                          [NonString(), NonString()])

    def testRepr(self):
        # verify repr works
        self.assert_(repr(self.f).startswith("<open file '" + TESTFN))

    def testErrors(self):
        f = self.f
        self.assertEquals(f.name, TESTFN)
        self.assert_(not f.isatty())
        self.assert_(not f.closed)

        self.assertRaises(TypeError, f.readinto, "")
        f.close()
        self.assert_(f.closed)

    def testMethods(self):
        methods = ['fileno', 'flush', 'isatty', 'next', 'read', 'readinto',
                   'readline', 'readlines', 'seek', 'tell', 'truncate',
                   'write', '__iter__']
        if sys.platform.startswith('atheos'):
            methods.remove('truncate')

        # __exit__ should close the file
        self.f.__exit__(None, None, None)
        self.assert_(self.f.closed)

        for methodname in methods:
            method = getattr(self.f, methodname)
            # should raise on closed file
            self.assertRaises(ValueError, method)
        self.assertRaises(ValueError, self.f.writelines, [])

        # file is closed, __exit__ shouldn't do anything
        self.assertEquals(self.f.__exit__(None, None, None), None)
        # it must also return None if an exception was given
        try:
            1/0
        except:
            self.assertEquals(self.f.__exit__(*sys.exc_info()), None)


class OtherFileTests(unittest.TestCase):

    def testModeStrings(self):
        # check invalid mode strings
        for mode in ("", "aU", "wU+"):
            try:
                f = open(TESTFN, mode)
            except ValueError:
                pass
            else:
                f.close()
                self.fail('%r is an invalid file mode' % mode)

    def testStdin(self):
        # This causes the interpreter to exit on OSF1 v5.1.
        if sys.platform != 'osf1V5':
            self.assertRaises(IOError, sys.stdin.seek, -1)
        else:
            print((
                '  Skipping sys.stdin.seek(-1), it may crash the interpreter.'
                ' Test manually.'), file=sys.__stdout__)
        self.assertRaises(IOError, sys.stdin.truncate)

    def testUnicodeOpen(self):
        # verify repr works for unicode too
        f = open(unicode(TESTFN), "w")
        self.assert_(repr(f).startswith("<open file u'" + TESTFN))
        f.close()
        os.unlink(TESTFN)

    def testBadModeArgument(self):
        # verify that we get a sensible error message for bad mode argument
        bad_mode = "qwerty"
        try:
            f = open(TESTFN, bad_mode)
        except ValueError as msg:
            if msg.message != 0:
                s = str(msg)
                if s.find(TESTFN) != -1 or s.find(bad_mode) == -1:
                    self.fail("bad error message for invalid mode: %s" % s)
            # if msg[0] == 0, we're probably on Windows where there may be
            # no obvious way to discover why open() failed.
        else:
            f.close()
            self.fail("no error for invalid mode: %s" % bad_mode)

    def testSetBufferSize(self):
        # make sure that explicitly setting the buffer size doesn't cause
        # misbehaviour especially with repeated close() calls
        for s in (-1, 0, 1, 512):
            try:
                f = open(TESTFN, 'w', s)
                f.write(str(s))
                f.close()
                f.close()
                f = open(TESTFN, 'r', s)
                d = int(f.read())
                f.close()
                f.close()
            except IOError as msg:
                self.fail('error setting buffer size %d: %s' % (s, str(msg)))
            self.assertEquals(d, s)

    def testTruncateOnWindows(self):
        os.unlink(TESTFN)

        def bug801631():
            # SF bug <http://www.python.org/sf/801631>
            # "file.truncate fault on windows"
            f = open(TESTFN, 'wb')
            f.write('12345678901')   # 11 bytes
            f.close()

            f = open(TESTFN,'rb+')
            data = f.read(5)
            if data != '12345':
                self.fail("Read on file opened for update failed %r" % data)
            if f.tell() != 5:
                self.fail("File pos after read wrong %d" % f.tell())

            f.truncate()
            if f.tell() != 5:
                self.fail("File pos after ftruncate wrong %d" % f.tell())

            f.close()
            size = os.path.getsize(TESTFN)
            if size != 5:
                self.fail("File size after ftruncate wrong %d" % size)

        try:
            bug801631()
        finally:
            os.unlink(TESTFN)

    def testIteration(self):
        # Test the complex interaction when mixing file-iteration and the
        # various read* methods. Ostensibly, the mixture could just be tested
        # to work when it should work according to the Python language,
        # instead of fail when it should fail according to the current CPython
        # implementation.  People don't always program Python the way they
        # should, though, and the implemenation might change in subtle ways,
        # so we explicitly test for errors, too; the test will just have to
        # be updated when the implementation changes.
        dataoffset = 16384
        filler = "ham\n"
        assert not dataoffset % len(filler), \
            "dataoffset must be multiple of len(filler)"
        nchunks = dataoffset // len(filler)
        testlines = [
            "spam, spam and eggs\n",
            "eggs, spam, ham and spam\n",
            "saussages, spam, spam and eggs\n",
            "spam, ham, spam and eggs\n",
            "spam, spam, spam, spam, spam, ham, spam\n",
            "wonderful spaaaaaam.\n"
        ]
        methods = [("readline", ()), ("read", ()), ("readlines", ()),
                   ("readinto", (array("c", " "*100),))]

        try:
            # Prepare the testfile
            bag = open(TESTFN, "wb")
            bag.write(filler * nchunks)
            bag.writelines(testlines)
            bag.close()
            # Test for appropriate errors mixing read* and iteration
            for methodname, args in methods:
                f = open(TESTFN, 'rb')
                if f.next() != filler:
                    self.fail, "Broken testfile"
                meth = getattr(f, methodname)
                try:
                    meth(*args)
                except ValueError:
                    pass
                else:
                    self.fail("%s%r after next() didn't raise ValueError" %
                                     (methodname, args))
                f.close()

            # Test to see if harmless (by accident) mixing of read* and
            # iteration still works. This depends on the size of the internal
            # iteration buffer (currently 8192,) but we can test it in a
            # flexible manner.  Each line in the bag o' ham is 4 bytes
            # ("h", "a", "m", "\n"), so 4096 lines of that should get us
            # exactly on the buffer boundary for any power-of-2 buffersize
            # between 4 and 16384 (inclusive).
            f = open(TESTFN, 'rb')
            for i in range(nchunks):
                f.next()
            testline = testlines.pop(0)
            try:
                line = f.readline()
            except ValueError:
                self.fail("readline() after next() with supposedly empty "
                          "iteration-buffer failed anyway")
            if line != testline:
                self.fail("readline() after next() with empty buffer "
                          "failed. Got %r, expected %r" % (line, testline))
            testline = testlines.pop(0)
            buf = array("c", "\x00" * len(testline))
            try:
                f.readinto(buf)
            except ValueError:
                self.fail("readinto() after next() with supposedly empty "
                          "iteration-buffer failed anyway")
            line = buf.tostring()
            if line != testline:
                self.fail("readinto() after next() with empty buffer "
                          "failed. Got %r, expected %r" % (line, testline))

            testline = testlines.pop(0)
            try:
                line = f.read(len(testline))
            except ValueError:
                self.fail("read() after next() with supposedly empty "
                          "iteration-buffer failed anyway")
            if line != testline:
                self.fail("read() after next() with empty buffer "
                          "failed. Got %r, expected %r" % (line, testline))
            try:
                lines = f.readlines()
            except ValueError:
                self.fail("readlines() after next() with supposedly empty "
                          "iteration-buffer failed anyway")
            if lines != testlines:
                self.fail("readlines() after next() with empty buffer "
                          "failed. Got %r, expected %r" % (line, testline))
            # Reading after iteration hit EOF shouldn't hurt either
            f = open(TESTFN, 'rb')
            try:
                for line in f:
                    pass
                try:
                    f.readline()
                    f.readinto(buf)
                    f.read()
                    f.readlines()
                except ValueError:
                    self.fail("read* failed after next() consumed file")
            finally:
                f.close()
        finally:
            os.unlink(TESTFN)


def test_main():
    # Historically, these tests have been sloppy about removing TESTFN.
    # So get rid of it no matter what.
    try:
        run_unittest(AutoFileTests, OtherFileTests)
    finally:
        if os.path.exists(TESTFN):
            os.unlink(TESTFN)

if __name__ == '__main__':
    test_main()