summaryrefslogtreecommitdiff
path: root/Lib/test/test_codeccallbacks.py
blob: 84804bb0dafa51692a1611104812eee41fbcaaac (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
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
import codecs
import html.entities
import sys
import test.support
import unicodedata
import unittest
import warnings

try:
    import ctypes
except ImportError:
    ctypes = None
    SIZEOF_WCHAR_T = -1
else:
    SIZEOF_WCHAR_T = ctypes.sizeof(ctypes.c_wchar)

class PosReturn:
    # this can be used for configurable callbacks

    def __init__(self):
        self.pos = 0

    def handle(self, exc):
        oldpos = self.pos
        realpos = oldpos
        if realpos<0:
            realpos = len(exc.object) + realpos
        # if we don't advance this time, terminate on the next call
        # otherwise we'd get an endless loop
        if realpos <= exc.start:
            self.pos = len(exc.object)
        return ("<?>", oldpos)

# A UnicodeEncodeError object with a bad start attribute
class BadStartUnicodeEncodeError(UnicodeEncodeError):
    def __init__(self):
        UnicodeEncodeError.__init__(self, "ascii", "", 0, 1, "bad")
        self.start = []

# A UnicodeEncodeError object with a bad object attribute
class BadObjectUnicodeEncodeError(UnicodeEncodeError):
    def __init__(self):
        UnicodeEncodeError.__init__(self, "ascii", "", 0, 1, "bad")
        self.object = []

# A UnicodeDecodeError object without an end attribute
class NoEndUnicodeDecodeError(UnicodeDecodeError):
    def __init__(self):
        UnicodeDecodeError.__init__(self, "ascii", bytearray(b""), 0, 1, "bad")
        del self.end

# A UnicodeDecodeError object with a bad object attribute
class BadObjectUnicodeDecodeError(UnicodeDecodeError):
    def __init__(self):
        UnicodeDecodeError.__init__(self, "ascii", bytearray(b""), 0, 1, "bad")
        self.object = []

# A UnicodeTranslateError object without a start attribute
class NoStartUnicodeTranslateError(UnicodeTranslateError):
    def __init__(self):
        UnicodeTranslateError.__init__(self, "", 0, 1, "bad")
        del self.start

# A UnicodeTranslateError object without an end attribute
class NoEndUnicodeTranslateError(UnicodeTranslateError):
    def __init__(self):
        UnicodeTranslateError.__init__(self,  "", 0, 1, "bad")
        del self.end

# A UnicodeTranslateError object without an object attribute
class NoObjectUnicodeTranslateError(UnicodeTranslateError):
    def __init__(self):
        UnicodeTranslateError.__init__(self, "", 0, 1, "bad")
        del self.object

class CodecCallbackTest(unittest.TestCase):

    def test_xmlcharrefreplace(self):
        # replace unencodable characters which numeric character entities.
        # For ascii, latin-1 and charmaps this is completely implemented
        # in C and should be reasonably fast.
        s = "\u30b9\u30d1\u30e2 \xe4nd eggs"
        self.assertEqual(
            s.encode("ascii", "xmlcharrefreplace"),
            b"&#12473;&#12497;&#12514; &#228;nd eggs"
        )
        self.assertEqual(
            s.encode("latin-1", "xmlcharrefreplace"),
            b"&#12473;&#12497;&#12514; \xe4nd eggs"
        )

    def test_xmlcharnamereplace(self):
        # This time use a named character entity for unencodable
        # characters, if one is available.

        def xmlcharnamereplace(exc):
            if not isinstance(exc, UnicodeEncodeError):
                raise TypeError("don't know how to handle %r" % exc)
            l = []
            for c in exc.object[exc.start:exc.end]:
                try:
                    l.append("&%s;" % html.entities.codepoint2name[ord(c)])
                except KeyError:
                    l.append("&#%d;" % ord(c))
            return ("".join(l), exc.end)

        codecs.register_error(
            "test.xmlcharnamereplace", xmlcharnamereplace)

        sin = "\xab\u211c\xbb = \u2329\u1234\u20ac\u232a"
        sout = b"&laquo;&real;&raquo; = &lang;&#4660;&euro;&rang;"
        self.assertEqual(sin.encode("ascii", "test.xmlcharnamereplace"), sout)
        sout = b"\xab&real;\xbb = &lang;&#4660;&euro;&rang;"
        self.assertEqual(sin.encode("latin-1", "test.xmlcharnamereplace"), sout)
        sout = b"\xab&real;\xbb = &lang;&#4660;\xa4&rang;"
        self.assertEqual(sin.encode("iso-8859-15", "test.xmlcharnamereplace"), sout)

    def test_uninamereplace(self):
        # We're using the names from the unicode database this time,
        # and we're doing "syntax highlighting" here, i.e. we include
        # the replaced text in ANSI escape sequences. For this it is
        # useful that the error handler is not called for every single
        # unencodable character, but for a complete sequence of
        # unencodable characters, otherwise we would output many
        # unnecessary escape sequences.

        def uninamereplace(exc):
            if not isinstance(exc, UnicodeEncodeError):
                raise TypeError("don't know how to handle %r" % exc)
            l = []
            for c in exc.object[exc.start:exc.end]:
                l.append(unicodedata.name(c, "0x%x" % ord(c)))
            return ("\033[1m%s\033[0m" % ", ".join(l), exc.end)

        codecs.register_error(
            "test.uninamereplace", uninamereplace)

        sin = "\xac\u1234\u20ac\u8000"
        sout = b"\033[1mNOT SIGN, ETHIOPIC SYLLABLE SEE, EURO SIGN, CJK UNIFIED IDEOGRAPH-8000\033[0m"
        self.assertEqual(sin.encode("ascii", "test.uninamereplace"), sout)

        sout = b"\xac\033[1mETHIOPIC SYLLABLE SEE, EURO SIGN, CJK UNIFIED IDEOGRAPH-8000\033[0m"
        self.assertEqual(sin.encode("latin-1", "test.uninamereplace"), sout)

        sout = b"\xac\033[1mETHIOPIC SYLLABLE SEE\033[0m\xa4\033[1mCJK UNIFIED IDEOGRAPH-8000\033[0m"
        self.assertEqual(sin.encode("iso-8859-15", "test.uninamereplace"), sout)

    def test_backslashescape(self):
        # Does the same as the "unicode-escape" encoding, but with different
        # base encodings.
        sin = "a\xac\u1234\u20ac\u8000\U0010ffff"
        sout = b"a\\xac\\u1234\\u20ac\\u8000\\U0010ffff"
        self.assertEqual(sin.encode("ascii", "backslashreplace"), sout)

        sout = b"a\xac\\u1234\\u20ac\\u8000\\U0010ffff"
        self.assertEqual(sin.encode("latin-1", "backslashreplace"), sout)

        sout = b"a\xac\\u1234\xa4\\u8000\\U0010ffff"
        self.assertEqual(sin.encode("iso-8859-15", "backslashreplace"), sout)

    def test_decoding_callbacks(self):
        # This is a test for a decoding callback handler
        # that allows the decoding of the invalid sequence
        # "\xc0\x80" and returns "\x00" instead of raising an error.
        # All other illegal sequences will be handled strictly.
        def relaxedutf8(exc):
            if not isinstance(exc, UnicodeDecodeError):
                raise TypeError("don't know how to handle %r" % exc)
            if exc.object[exc.start:exc.start+2] == b"\xc0\x80":
                return ("\x00", exc.start+2) # retry after two bytes
            else:
                raise exc

        codecs.register_error("test.relaxedutf8", relaxedutf8)

        # all the "\xc0\x80" will be decoded to "\x00"
        sin = b"a\x00b\xc0\x80c\xc3\xbc\xc0\x80\xc0\x80"
        sout = "a\x00b\x00c\xfc\x00\x00"
        self.assertEqual(sin.decode("utf-8", "test.relaxedutf8"), sout)

        # "\xc0\x81" is not valid and a UnicodeDecodeError will be raised
        sin = b"\xc0\x80\xc0\x81"
        self.assertRaises(UnicodeDecodeError, sin.decode,
                          "utf-8", "test.relaxedutf8")

    def test_charmapencode(self):
        # For charmap encodings the replacement string will be
        # mapped through the encoding again. This means, that
        # to be able to use e.g. the "replace" handler, the
        # charmap has to have a mapping for "?".
        charmap = dict((ord(c), bytes(2*c.upper(), 'ascii')) for c in "abcdefgh")
        sin = "abc"
        sout = b"AABBCC"
        self.assertEqual(codecs.charmap_encode(sin, "strict", charmap)[0], sout)

        sin = "abcA"
        self.assertRaises(UnicodeError, codecs.charmap_encode, sin, "strict", charmap)

        charmap[ord("?")] = b"XYZ"
        sin = "abcDEF"
        sout = b"AABBCCXYZXYZXYZ"
        self.assertEqual(codecs.charmap_encode(sin, "replace", charmap)[0], sout)

        charmap[ord("?")] = "XYZ" # wrong type in mapping
        self.assertRaises(TypeError, codecs.charmap_encode, sin, "replace", charmap)

    def test_decodeunicodeinternal(self):
        with test.support.check_warnings(('unicode_internal codec has been '
                                          'deprecated', DeprecationWarning)):
            self.assertRaises(
                UnicodeDecodeError,
                b"\x00\x00\x00\x00\x00".decode,
                "unicode-internal",
            )
        if SIZEOF_WCHAR_T == 4:
            def handler_unicodeinternal(exc):
                if not isinstance(exc, UnicodeDecodeError):
                    raise TypeError("don't know how to handle %r" % exc)
                return ("\x01", 1)

            with test.support.check_warnings(('unicode_internal codec has been '
                                              'deprecated', DeprecationWarning)):
                self.assertEqual(
                    b"\x00\x00\x00\x00\x00".decode("unicode-internal", "ignore"),
                    "\u0000"
                )

                self.assertEqual(
                    b"\x00\x00\x00\x00\x00".decode("unicode-internal", "replace"),
                    "\u0000\ufffd"
                )

                codecs.register_error("test.hui", handler_unicodeinternal)

                self.assertEqual(
                    b"\x00\x00\x00\x00\x00".decode("unicode-internal", "test.hui"),
                    "\u0000\u0001\u0000"
                )

    def test_callbacks(self):
        def handler1(exc):
            r = range(exc.start, exc.end)
            if isinstance(exc, UnicodeEncodeError):
                l = ["<%d>" % ord(exc.object[pos]) for pos in r]
            elif isinstance(exc, UnicodeDecodeError):
                l = ["<%d>" % exc.object[pos] for pos in r]
            else:
                raise TypeError("don't know how to handle %r" % exc)
            return ("[%s]" % "".join(l), exc.end)

        codecs.register_error("test.handler1", handler1)

        def handler2(exc):
            if not isinstance(exc, UnicodeDecodeError):
                raise TypeError("don't know how to handle %r" % exc)
            l = ["<%d>" % exc.object[pos] for pos in range(exc.start, exc.end)]
            return ("[%s]" % "".join(l), exc.end+1) # skip one character

        codecs.register_error("test.handler2", handler2)

        s = b"\x00\x81\x7f\x80\xff"

        self.assertEqual(
            s.decode("ascii", "test.handler1"),
            "\x00[<129>]\x7f[<128>][<255>]"
        )
        self.assertEqual(
            s.decode("ascii", "test.handler2"),
            "\x00[<129>][<128>]"
        )

        self.assertEqual(
            b"\\u3042\u3xxx".decode("unicode-escape", "test.handler1"),
            "\u3042[<92><117><51>]xxx"
        )

        self.assertEqual(
            b"\\u3042\u3xx".decode("unicode-escape", "test.handler1"),
            "\u3042[<92><117><51>]xx"
        )

        self.assertEqual(
            codecs.charmap_decode(b"abc", "test.handler1", {ord("a"): "z"})[0],
            "z[<98>][<99>]"
        )

        self.assertEqual(
            "g\xfc\xdfrk".encode("ascii", "test.handler1"),
            b"g[<252><223>]rk"
        )

        self.assertEqual(
            "g\xfc\xdf".encode("ascii", "test.handler1"),
            b"g[<252><223>]"
        )

    def test_longstrings(self):
        # test long strings to check for memory overflow problems
        errors = [ "strict", "ignore", "replace", "xmlcharrefreplace",
                   "backslashreplace"]
        # register the handlers under different names,
        # to prevent the codec from recognizing the name
        for err in errors:
            codecs.register_error("test." + err, codecs.lookup_error(err))
        l = 1000
        errors += [ "test." + err for err in errors ]
        for uni in [ s*l for s in ("x", "\u3042", "a\xe4") ]:
            for enc in ("ascii", "latin-1", "iso-8859-1", "iso-8859-15",
                        "utf-8", "utf-7", "utf-16", "utf-32"):
                for err in errors:
                    try:
                        uni.encode(enc, err)
                    except UnicodeError:
                        pass

    def check_exceptionobjectargs(self, exctype, args, msg):
        # Test UnicodeError subclasses: construction, attribute assignment and __str__ conversion
        # check with one missing argument
        self.assertRaises(TypeError, exctype, *args[:-1])
        # check with one argument too much
        self.assertRaises(TypeError, exctype, *(args + ["too much"]))
        # check with one argument of the wrong type
        wrongargs = [ "spam", b"eggs", b"spam", 42, 1.0, None ]
        for i in range(len(args)):
            for wrongarg in wrongargs:
                if type(wrongarg) is type(args[i]):
                    continue
                # build argument array
                callargs = []
                for j in range(len(args)):
                    if i==j:
                        callargs.append(wrongarg)
                    else:
                        callargs.append(args[i])
                self.assertRaises(TypeError, exctype, *callargs)

        # check with the correct number and type of arguments
        exc = exctype(*args)
        self.assertEqual(str(exc), msg)

    def test_unicodeencodeerror(self):
        self.check_exceptionobjectargs(
            UnicodeEncodeError,
            ["ascii", "g\xfcrk", 1, 2, "ouch"],
            "'ascii' codec can't encode character '\\xfc' in position 1: ouch"
        )
        self.check_exceptionobjectargs(
            UnicodeEncodeError,
            ["ascii", "g\xfcrk", 1, 4, "ouch"],
            "'ascii' codec can't encode characters in position 1-3: ouch"
        )
        self.check_exceptionobjectargs(
            UnicodeEncodeError,
            ["ascii", "\xfcx", 0, 1, "ouch"],
            "'ascii' codec can't encode character '\\xfc' in position 0: ouch"
        )
        self.check_exceptionobjectargs(
            UnicodeEncodeError,
            ["ascii", "\u0100x", 0, 1, "ouch"],
            "'ascii' codec can't encode character '\\u0100' in position 0: ouch"
        )
        self.check_exceptionobjectargs(
            UnicodeEncodeError,
            ["ascii", "\uffffx", 0, 1, "ouch"],
            "'ascii' codec can't encode character '\\uffff' in position 0: ouch"
        )
        if SIZEOF_WCHAR_T == 4:
            self.check_exceptionobjectargs(
                UnicodeEncodeError,
                ["ascii", "\U00010000x", 0, 1, "ouch"],
                "'ascii' codec can't encode character '\\U00010000' in position 0: ouch"
            )

    def test_unicodedecodeerror(self):
        self.check_exceptionobjectargs(
            UnicodeDecodeError,
            ["ascii", bytearray(b"g\xfcrk"), 1, 2, "ouch"],
            "'ascii' codec can't decode byte 0xfc in position 1: ouch"
        )
        self.check_exceptionobjectargs(
            UnicodeDecodeError,
            ["ascii", bytearray(b"g\xfcrk"), 1, 3, "ouch"],
            "'ascii' codec can't decode bytes in position 1-2: ouch"
        )

    def test_unicodetranslateerror(self):
        self.check_exceptionobjectargs(
            UnicodeTranslateError,
            ["g\xfcrk", 1, 2, "ouch"],
            "can't translate character '\\xfc' in position 1: ouch"
        )
        self.check_exceptionobjectargs(
            UnicodeTranslateError,
            ["g\u0100rk", 1, 2, "ouch"],
            "can't translate character '\\u0100' in position 1: ouch"
        )
        self.check_exceptionobjectargs(
            UnicodeTranslateError,
            ["g\uffffrk", 1, 2, "ouch"],
            "can't translate character '\\uffff' in position 1: ouch"
        )
        if SIZEOF_WCHAR_T == 4:
            self.check_exceptionobjectargs(
                UnicodeTranslateError,
                ["g\U00010000rk", 1, 2, "ouch"],
                "can't translate character '\\U00010000' in position 1: ouch"
            )
        self.check_exceptionobjectargs(
            UnicodeTranslateError,
            ["g\xfcrk", 1, 3, "ouch"],
            "can't translate characters in position 1-2: ouch"
        )

    def test_badandgoodstrictexceptions(self):
        # "strict" complains about a non-exception passed in
        self.assertRaises(
            TypeError,
            codecs.strict_errors,
            42
        )
        # "strict" complains about the wrong exception type
        self.assertRaises(
            Exception,
            codecs.strict_errors,
            Exception("ouch")
        )

        # If the correct exception is passed in, "strict" raises it
        self.assertRaises(
            UnicodeEncodeError,
            codecs.strict_errors,
            UnicodeEncodeError("ascii", "\u3042", 0, 1, "ouch")
        )

    def test_badandgoodignoreexceptions(self):
        # "ignore" complains about a non-exception passed in
        self.assertRaises(
           TypeError,
           codecs.ignore_errors,
           42
        )
        # "ignore" complains about the wrong exception type
        self.assertRaises(
           TypeError,
           codecs.ignore_errors,
           UnicodeError("ouch")
        )
        # If the correct exception is passed in, "ignore" returns an empty replacement
        self.assertEqual(
            codecs.ignore_errors(
                UnicodeEncodeError("ascii", "\u3042", 0, 1, "ouch")),
            ("", 1)
        )
        self.assertEqual(
            codecs.ignore_errors(
                UnicodeDecodeError("ascii", bytearray(b"\xff"), 0, 1, "ouch")),
            ("", 1)
        )
        self.assertEqual(
            codecs.ignore_errors(
                UnicodeTranslateError("\u3042", 0, 1, "ouch")),
            ("", 1)
        )

    def test_badandgoodreplaceexceptions(self):
        # "replace" complains about a non-exception passed in
        self.assertRaises(
           TypeError,
           codecs.replace_errors,
           42
        )
        # "replace" complains about the wrong exception type
        self.assertRaises(
           TypeError,
           codecs.replace_errors,
           UnicodeError("ouch")
        )
        self.assertRaises(
            TypeError,
            codecs.replace_errors,
            BadObjectUnicodeEncodeError()
        )
        self.assertRaises(
            TypeError,
            codecs.replace_errors,
            BadObjectUnicodeDecodeError()
        )
        # With the correct exception, "replace" returns an "?" or "\ufffd" replacement
        self.assertEqual(
            codecs.replace_errors(
                UnicodeEncodeError("ascii", "\u3042", 0, 1, "ouch")),
            ("?", 1)
        )
        self.assertEqual(
            codecs.replace_errors(
                UnicodeDecodeError("ascii", bytearray(b"\xff"), 0, 1, "ouch")),
            ("\ufffd", 1)
        )
        self.assertEqual(
            codecs.replace_errors(
                UnicodeTranslateError("\u3042", 0, 1, "ouch")),
            ("\ufffd", 1)
        )

    def test_badandgoodxmlcharrefreplaceexceptions(self):
        # "xmlcharrefreplace" complains about a non-exception passed in
        self.assertRaises(
           TypeError,
           codecs.xmlcharrefreplace_errors,
           42
        )
        # "xmlcharrefreplace" complains about the wrong exception types
        self.assertRaises(
           TypeError,
           codecs.xmlcharrefreplace_errors,
           UnicodeError("ouch")
        )
        # "xmlcharrefreplace" can only be used for encoding
        self.assertRaises(
            TypeError,
            codecs.xmlcharrefreplace_errors,
            UnicodeDecodeError("ascii", bytearray(b"\xff"), 0, 1, "ouch")
        )
        self.assertRaises(
            TypeError,
            codecs.xmlcharrefreplace_errors,
            UnicodeTranslateError("\u3042", 0, 1, "ouch")
        )
        # Use the correct exception
        cs = (0, 1, 9, 10, 99, 100, 999, 1000, 9999, 10000, 0x3042)
        s = "".join(chr(c) for c in cs)
        self.assertEqual(
            codecs.xmlcharrefreplace_errors(
                UnicodeEncodeError("ascii", s, 0, len(s), "ouch")
            ),
            ("".join("&#%d;" % ord(c) for c in s), len(s))
        )

    def test_badandgoodbackslashreplaceexceptions(self):
        # "backslashreplace" complains about a non-exception passed in
        self.assertRaises(
           TypeError,
           codecs.backslashreplace_errors,
           42
        )
        # "backslashreplace" complains about the wrong exception types
        self.assertRaises(
           TypeError,
           codecs.backslashreplace_errors,
           UnicodeError("ouch")
        )
        # "backslashreplace" can only be used for encoding
        self.assertRaises(
            TypeError,
            codecs.backslashreplace_errors,
            UnicodeDecodeError("ascii", bytearray(b"\xff"), 0, 1, "ouch")
        )
        self.assertRaises(
            TypeError,
            codecs.backslashreplace_errors,
            UnicodeTranslateError("\u3042", 0, 1, "ouch")
        )
        # Use the correct exception
        self.assertEqual(
            codecs.backslashreplace_errors(
                UnicodeEncodeError("ascii", "\u3042", 0, 1, "ouch")),
            ("\\u3042", 1)
        )
        self.assertEqual(
            codecs.backslashreplace_errors(
                UnicodeEncodeError("ascii", "\x00", 0, 1, "ouch")),
            ("\\x00", 1)
        )
        self.assertEqual(
            codecs.backslashreplace_errors(
                UnicodeEncodeError("ascii", "\xff", 0, 1, "ouch")),
            ("\\xff", 1)
        )
        self.assertEqual(
            codecs.backslashreplace_errors(
                UnicodeEncodeError("ascii", "\u0100", 0, 1, "ouch")),
            ("\\u0100", 1)
        )
        self.assertEqual(
            codecs.backslashreplace_errors(
                UnicodeEncodeError("ascii", "\uffff", 0, 1, "ouch")),
            ("\\uffff", 1)
        )
        if SIZEOF_WCHAR_T > 0:
            self.assertEqual(
                codecs.backslashreplace_errors(
                    UnicodeEncodeError("ascii", "\U00010000",
                                       0, 1, "ouch")),
                ("\\U00010000", 1)
            )
            self.assertEqual(
                codecs.backslashreplace_errors(
                    UnicodeEncodeError("ascii", "\U0010ffff",
                                       0, 1, "ouch")),
                ("\\U0010ffff", 1)
            )
            # Lone surrogates (regardless of unicode width)
            self.assertEqual(
                codecs.backslashreplace_errors(
                    UnicodeEncodeError("ascii", "\ud800", 0, 1, "ouch")),
                ("\\ud800", 1)
            )
            self.assertEqual(
                codecs.backslashreplace_errors(
                    UnicodeEncodeError("ascii", "\udfff", 0, 1, "ouch")),
                ("\\udfff", 1)
            )

    def test_badhandlerresults(self):
        results = ( 42, "foo", (1,2,3), ("foo", 1, 3), ("foo", None), ("foo",), ("foo", 1, 3), ("foo", None), ("foo",) )
        encs = ("ascii", "latin-1", "iso-8859-1", "iso-8859-15")

        for res in results:
            codecs.register_error("test.badhandler", lambda x: res)
            for enc in encs:
                self.assertRaises(
                    TypeError,
                    "\u3042".encode,
                    enc,
                    "test.badhandler"
                )
            for (enc, bytes) in (
                ("ascii", b"\xff"),
                ("utf-8", b"\xff"),
                ("utf-7", b"+x-"),
                ("unicode-internal", b"\x00"),
            ):
                with test.support.check_warnings():
                    # unicode-internal has been deprecated
                    self.assertRaises(
                        TypeError,
                        bytes.decode,
                        enc,
                        "test.badhandler"
                    )

    def test_lookup(self):
        self.assertEqual(codecs.strict_errors, codecs.lookup_error("strict"))
        self.assertEqual(codecs.ignore_errors, codecs.lookup_error("ignore"))
        self.assertEqual(codecs.strict_errors, codecs.lookup_error("strict"))
        self.assertEqual(
            codecs.xmlcharrefreplace_errors,
            codecs.lookup_error("xmlcharrefreplace")
        )
        self.assertEqual(
            codecs.backslashreplace_errors,
            codecs.lookup_error("backslashreplace")
        )

    def test_unencodablereplacement(self):
        def unencrepl(exc):
            if isinstance(exc, UnicodeEncodeError):
                return ("\u4242", exc.end)
            else:
                raise TypeError("don't know how to handle %r" % exc)
        codecs.register_error("test.unencreplhandler", unencrepl)
        for enc in ("ascii", "iso-8859-1", "iso-8859-15"):
            self.assertRaises(
                UnicodeEncodeError,
                "\u4242".encode,
                enc,
                "test.unencreplhandler"
            )

    def test_badregistercall(self):
        # enhance coverage of:
        # Modules/_codecsmodule.c::register_error()
        # Python/codecs.c::PyCodec_RegisterError()
        self.assertRaises(TypeError, codecs.register_error, 42)
        self.assertRaises(TypeError, codecs.register_error, "test.dummy", 42)

    def test_badlookupcall(self):
        # enhance coverage of:
        # Modules/_codecsmodule.c::lookup_error()
        self.assertRaises(TypeError, codecs.lookup_error)

    def test_unknownhandler(self):
        # enhance coverage of:
        # Modules/_codecsmodule.c::lookup_error()
        self.assertRaises(LookupError, codecs.lookup_error, "test.unknown")

    def test_xmlcharrefvalues(self):
        # enhance coverage of:
        # Python/codecs.c::PyCodec_XMLCharRefReplaceErrors()
        # and inline implementations
        v = (1, 5, 10, 50, 100, 500, 1000, 5000, 10000, 50000)
        if SIZEOF_WCHAR_T == 4:
            v += (100000, 500000, 1000000)
        s = "".join([chr(x) for x in v])
        codecs.register_error("test.xmlcharrefreplace", codecs.xmlcharrefreplace_errors)
        for enc in ("ascii", "iso-8859-15"):
            for err in ("xmlcharrefreplace", "test.xmlcharrefreplace"):
                s.encode(enc, err)

    def test_decodehelper(self):
        # enhance coverage of:
        # Objects/unicodeobject.c::unicode_decode_call_errorhandler()
        # and callers
        self.assertRaises(LookupError, b"\xff".decode, "ascii", "test.unknown")

        def baddecodereturn1(exc):
            return 42
        codecs.register_error("test.baddecodereturn1", baddecodereturn1)
        self.assertRaises(TypeError, b"\xff".decode, "ascii", "test.baddecodereturn1")
        self.assertRaises(TypeError, b"\\".decode, "unicode-escape", "test.baddecodereturn1")
        self.assertRaises(TypeError, b"\\x0".decode, "unicode-escape", "test.baddecodereturn1")
        self.assertRaises(TypeError, b"\\x0y".decode, "unicode-escape", "test.baddecodereturn1")
        self.assertRaises(TypeError, b"\\Uffffeeee".decode, "unicode-escape", "test.baddecodereturn1")
        self.assertRaises(TypeError, b"\\uyyyy".decode, "raw-unicode-escape", "test.baddecodereturn1")

        def baddecodereturn2(exc):
            return ("?", None)
        codecs.register_error("test.baddecodereturn2", baddecodereturn2)
        self.assertRaises(TypeError, b"\xff".decode, "ascii", "test.baddecodereturn2")

        handler = PosReturn()
        codecs.register_error("test.posreturn", handler.handle)

        # Valid negative position
        handler.pos = -1
        self.assertEqual(b"\xff0".decode("ascii", "test.posreturn"), "<?>0")

        # Valid negative position
        handler.pos = -2
        self.assertEqual(b"\xff0".decode("ascii", "test.posreturn"), "<?><?>")

        # Negative position out of bounds
        handler.pos = -3
        self.assertRaises(IndexError, b"\xff0".decode, "ascii", "test.posreturn")

        # Valid positive position
        handler.pos = 1
        self.assertEqual(b"\xff0".decode("ascii", "test.posreturn"), "<?>0")

        # Largest valid positive position (one beyond end of input)
        handler.pos = 2
        self.assertEqual(b"\xff0".decode("ascii", "test.posreturn"), "<?>")

        # Invalid positive position
        handler.pos = 3
        self.assertRaises(IndexError, b"\xff0".decode, "ascii", "test.posreturn")

        # Restart at the "0"
        handler.pos = 6
        self.assertEqual(b"\\uyyyy0".decode("raw-unicode-escape", "test.posreturn"), "<?>0")

        class D(dict):
            def __getitem__(self, key):
                raise ValueError
        self.assertRaises(UnicodeError, codecs.charmap_decode, b"\xff", "strict", {0xff: None})
        self.assertRaises(ValueError, codecs.charmap_decode, b"\xff", "strict", D())
        self.assertRaises(TypeError, codecs.charmap_decode, b"\xff", "strict", {0xff: sys.maxunicode+1})

    def test_encodehelper(self):
        # enhance coverage of:
        # Objects/unicodeobject.c::unicode_encode_call_errorhandler()
        # and callers
        self.assertRaises(LookupError, "\xff".encode, "ascii", "test.unknown")

        def badencodereturn1(exc):
            return 42
        codecs.register_error("test.badencodereturn1", badencodereturn1)
        self.assertRaises(TypeError, "\xff".encode, "ascii", "test.badencodereturn1")

        def badencodereturn2(exc):
            return ("?", None)
        codecs.register_error("test.badencodereturn2", badencodereturn2)
        self.assertRaises(TypeError, "\xff".encode, "ascii", "test.badencodereturn2")

        handler = PosReturn()
        codecs.register_error("test.posreturn", handler.handle)

        # Valid negative position
        handler.pos = -1
        self.assertEqual("\xff0".encode("ascii", "test.posreturn"), b"<?>0")

        # Valid negative position
        handler.pos = -2
        self.assertEqual("\xff0".encode("ascii", "test.posreturn"), b"<?><?>")

        # Negative position out of bounds
        handler.pos = -3
        self.assertRaises(IndexError, "\xff0".encode, "ascii", "test.posreturn")

        # Valid positive position
        handler.pos = 1
        self.assertEqual("\xff0".encode("ascii", "test.posreturn"), b"<?>0")

        # Largest valid positive position (one beyond end of input
        handler.pos = 2
        self.assertEqual("\xff0".encode("ascii", "test.posreturn"), b"<?>")

        # Invalid positive position
        handler.pos = 3
        self.assertRaises(IndexError, "\xff0".encode, "ascii", "test.posreturn")

        handler.pos = 0

        class D(dict):
            def __getitem__(self, key):
                raise ValueError
        for err in ("strict", "replace", "xmlcharrefreplace", "backslashreplace", "test.posreturn"):
            self.assertRaises(UnicodeError, codecs.charmap_encode, "\xff", err, {0xff: None})
            self.assertRaises(ValueError, codecs.charmap_encode, "\xff", err, D())
            self.assertRaises(TypeError, codecs.charmap_encode, "\xff", err, {0xff: 300})

    def test_translatehelper(self):
        # enhance coverage of:
        # Objects/unicodeobject.c::unicode_encode_call_errorhandler()
        # and callers
        # (Unfortunately the errors argument is not directly accessible
        # from Python, so we can't test that much)
        class D(dict):
            def __getitem__(self, key):
                raise ValueError
        #self.assertRaises(ValueError, "\xff".translate, D())
        self.assertRaises(TypeError, "\xff".translate, {0xff: sys.maxunicode+1})
        self.assertRaises(TypeError, "\xff".translate, {0xff: ()})

    def test_bug828737(self):
        charmap = {
            ord("&"): "&amp;",
            ord("<"): "&lt;",
            ord(">"): "&gt;",
            ord('"'): "&quot;",
        }

        for n in (1, 10, 100, 1000):
            text = 'abc<def>ghi'*n
            text.translate(charmap)

    def test_mutatingdecodehandler(self):
        baddata = [
            ("ascii", b"\xff"),
            ("utf-7", b"++"),
            ("utf-8",  b"\xff"),
            ("utf-16", b"\xff"),
            ("utf-32", b"\xff"),
            ("unicode-escape", b"\\u123g"),
            ("raw-unicode-escape", b"\\u123g"),
            ("unicode-internal", b"\xff"),
        ]

        def replacing(exc):
            if isinstance(exc, UnicodeDecodeError):
                exc.object = 42
                return ("\u4242", 0)
            else:
                raise TypeError("don't know how to handle %r" % exc)
        codecs.register_error("test.replacing", replacing)

        with test.support.check_warnings():
            # unicode-internal has been deprecated
            for (encoding, data) in baddata:
                with self.assertRaises(TypeError):
                    data.decode(encoding, "test.replacing")

        def mutating(exc):
            if isinstance(exc, UnicodeDecodeError):
                exc.object[:] = b""
                return ("\u4242", 0)
            else:
                raise TypeError("don't know how to handle %r" % exc)
        codecs.register_error("test.mutating", mutating)
        # If the decoder doesn't pick up the modified input the following
        # will lead to an endless loop
        with test.support.check_warnings():
            # unicode-internal has been deprecated
            for (encoding, data) in baddata:
                with self.assertRaises(TypeError):
                    data.decode(encoding, "test.replacing")


if __name__ == "__main__":
    unittest.main()