test_textwrap.py 29.8 KB
Newer Older
Greg Ward's avatar
Greg Ward committed
1
#
2
# Test suite for the textwrap module.
Greg Ward's avatar
Greg Ward committed
3 4 5 6 7 8 9 10
#
# Original tests written by Greg Ward <gward@python.net>.
# Converted to PyUnit by Peter Hansen <peter@engcorp.com>.
# Currently maintained by Greg Ward.
#
# $Id$
#

11
import unittest
12
from test import support
13

14
from textwrap import TextWrapper, wrap, fill, dedent, indent
15 16


17
class BaseTestCase(unittest.TestCase):
18 19 20 21 22 23 24
    '''Parent class with utility methods for textwrap tests.'''

    def show(self, textin):
        if isinstance(textin, list):
            result = []
            for i in range(len(textin)):
                result.append("  %d: %r" % (i, textin[i]))
25
            result = "\n".join(result) if result else "  no lines"
26
        elif isinstance(textin, str):
27 28 29 30 31
            result = "  %s\n" % repr(textin)
        return result


    def check(self, result, expect):
32
        self.assertEqual(result, expect,
33 34
            'expected:\n%s\nbut got:\n%s' % (
                self.show(expect), self.show(result)))
35

36 37
    def check_wrap(self, text, width, expect, **kwargs):
        result = wrap(text, width, **kwargs)
38 39
        self.check(result, expect)

40 41
    def check_split(self, text, expect):
        result = self.wrapper._split(text)
42 43 44
        self.assertEqual(result, expect,
                         "\nexpected %r\n"
                         "but got  %r" % (expect, result))
45

46

47
class WrapTestCase(BaseTestCase):
48 49

    def setUp(self):
50
        self.wrapper = TextWrapper(width=45)
51

52
    def test_simple(self):
53
        # Simple case: just words, spaces, and a bit of punctuation
54

55
        text = "Hello there, how are you this fine day?  I'm glad to hear it!"
56

57 58 59 60 61 62 63 64 65 66 67
        self.check_wrap(text, 12,
                        ["Hello there,",
                         "how are you",
                         "this fine",
                         "day?  I'm",
                         "glad to hear",
                         "it!"])
        self.check_wrap(text, 42,
                        ["Hello there, how are you this fine day?",
                         "I'm glad to hear it!"])
        self.check_wrap(text, 80, [text])
68

69 70 71 72 73 74 75 76 77
    def test_empty_string(self):
        # Check that wrapping the empty string returns an empty list.
        self.check_wrap("", 6, [])
        self.check_wrap("", 6, [], drop_whitespace=False)

    def test_empty_string_with_initial_indent(self):
        # Check that the empty string is not indented.
        self.check_wrap("", 6, [], initial_indent="++")
        self.check_wrap("", 6, [], initial_indent="++", drop_whitespace=False)
78

79
    def test_whitespace(self):
80
        # Whitespace munging and end-of-sentence detection
81

82
        text = """\
83 84 85 86 87 88 89
This is a paragraph that already has
line breaks.  But some of its lines are much longer than the others,
so it needs to be wrapped.
Some lines are \ttabbed too.
What a mess!
"""

90 91 92 93 94 95
        expect = ["This is a paragraph that already has line",
                  "breaks.  But some of its lines are much",
                  "longer than the others, so it needs to be",
                  "wrapped.  Some lines are  tabbed too.  What a",
                  "mess!"]

96 97
        wrapper = TextWrapper(45, fix_sentence_endings=True)
        result = wrapper.wrap(text)
98 99
        self.check(result, expect)

100
        result = wrapper.fill(text)
101 102
        self.check(result, '\n'.join(expect))

103 104 105 106 107 108 109 110
        text = "\tTest\tdefault\t\ttabsize."
        expect = ["        Test    default         tabsize."]
        self.check_wrap(text, 80, expect)

        text = "\tTest\tcustom\t\ttabsize."
        expect = ["    Test    custom      tabsize."]
        self.check_wrap(text, 80, expect, tabsize=4)

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
    def test_fix_sentence_endings(self):
        wrapper = TextWrapper(60, fix_sentence_endings=True)

        # SF #847346: ensure that fix_sentence_endings=True does the
        # right thing even on input short enough that it doesn't need to
        # be wrapped.
        text = "A short line. Note the single space."
        expect = ["A short line.  Note the single space."]
        self.check(wrapper.wrap(text), expect)

        # Test some of the hairy end cases that _fix_sentence_endings()
        # is supposed to handle (the easy stuff is tested in
        # test_whitespace() above).
        text = "Well, Doctor? What do you think?"
        expect = ["Well, Doctor?  What do you think?"]
        self.check(wrapper.wrap(text), expect)

        text = "Well, Doctor?\nWhat do you think?"
        self.check(wrapper.wrap(text), expect)

        text = 'I say, chaps! Anyone for "tennis?"\nHmmph!'
        expect = ['I say, chaps!  Anyone for "tennis?"  Hmmph!']
        self.check(wrapper.wrap(text), expect)

        wrapper.width = 20
        expect = ['I say, chaps!', 'Anyone for "tennis?"', 'Hmmph!']
        self.check(wrapper.wrap(text), expect)

        text = 'And she said, "Go to hell!"\nCan you believe that?'
        expect = ['And she said, "Go to',
                  'hell!"  Can you',
                  'believe that?']
        self.check(wrapper.wrap(text), expect)

        wrapper.width = 60
        expect = ['And she said, "Go to hell!"  Can you believe that?']
        self.check(wrapper.wrap(text), expect)
Tim Peters's avatar
Tim Peters committed
148

Christian Heimes's avatar
Christian Heimes committed
149 150 151 152
        text = 'File stdio.h is nice.'
        expect = ['File stdio.h is nice.']
        self.check(wrapper.wrap(text), expect)

153
    def test_wrap_short(self):
154
        # Wrapping to make short lines longer
155

156
        text = "This is a\nshort paragraph."
157

158 159 160
        self.check_wrap(text, 20, ["This is a short",
                                   "paragraph."])
        self.check_wrap(text, 40, ["This is a short paragraph."])
161 162


163 164 165 166 167 168 169 170 171 172
    def test_wrap_short_1line(self):
        # Test endcases

        text = "This is a short line."

        self.check_wrap(text, 30, ["This is a short line."])
        self.check_wrap(text, 30, ["(1) This is a short line."],
                        initial_indent="(1) ")


173
    def test_hyphenated(self):
174
        # Test breaking hyphenated words
175

176 177
        text = ("this-is-a-useful-feature-for-"
                "reformatting-posts-from-tim-peters'ly")
178

179 180 181 182 183 184 185 186 187
        self.check_wrap(text, 40,
                        ["this-is-a-useful-feature-for-",
                         "reformatting-posts-from-tim-peters'ly"])
        self.check_wrap(text, 41,
                        ["this-is-a-useful-feature-for-",
                         "reformatting-posts-from-tim-peters'ly"])
        self.check_wrap(text, 42,
                        ["this-is-a-useful-feature-for-reformatting-",
                         "posts-from-tim-peters'ly"])
188

189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206
    def test_hyphenated_numbers(self):
        # Test that hyphenated numbers (eg. dates) are not broken like words.
        text = ("Python 1.0.0 was released on 1994-01-26.  Python 1.0.1 was\n"
                "released on 1994-02-15.")

        self.check_wrap(text, 30, ['Python 1.0.0 was released on',
                                   '1994-01-26.  Python 1.0.1 was',
                                   'released on 1994-02-15.'])
        self.check_wrap(text, 40, ['Python 1.0.0 was released on 1994-01-26.',
                                   'Python 1.0.1 was released on 1994-02-15.'])

        text = "I do all my shopping at 7-11."
        self.check_wrap(text, 25, ["I do all my shopping at",
                                   "7-11."])
        self.check_wrap(text, 27, ["I do all my shopping at",
                                   "7-11."])
        self.check_wrap(text, 29, ["I do all my shopping at 7-11."])

207
    def test_em_dash(self):
208
        # Test text with em-dashes
209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224
        text = "Em-dashes should be written -- thus."
        self.check_wrap(text, 25,
                        ["Em-dashes should be",
                         "written -- thus."])

        # Probe the boundaries of the properly written em-dash,
        # ie. " -- ".
        self.check_wrap(text, 29,
                        ["Em-dashes should be written",
                         "-- thus."])
        expect = ["Em-dashes should be written --",
                  "thus."]
        self.check_wrap(text, 30, expect)
        self.check_wrap(text, 35, expect)
        self.check_wrap(text, 36,
                        ["Em-dashes should be written -- thus."])
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
        # The improperly written em-dash is handled too, because
        # it's adjacent to non-whitespace on both sides.
        text = "You can also do--this or even---this."
        expect = ["You can also do",
                  "--this or even",
                  "---this."]
        self.check_wrap(text, 15, expect)
        self.check_wrap(text, 16, expect)
        expect = ["You can also do--",
                  "this or even---",
                  "this."]
        self.check_wrap(text, 17, expect)
        self.check_wrap(text, 19, expect)
        expect = ["You can also do--this or even",
                  "---this."]
        self.check_wrap(text, 29, expect)
        self.check_wrap(text, 31, expect)
        expect = ["You can also do--this or even---",
                  "this."]
        self.check_wrap(text, 32, expect)
        self.check_wrap(text, 35, expect)

        # All of the above behaviour could be deduced by probing the
        # _split() method.
        text = "Here's an -- em-dash and--here's another---and another!"
        expect = ["Here's", " ", "an", " ", "--", " ", "em-", "dash", " ",
                  "and", "--", "here's", " ", "another", "---",
                  "and", " ", "another!"]
254
        self.check_split(text, expect)
255

256 257 258
        text = "and then--bam!--he was gone"
        expect = ["and", " ", "then", "--", "bam!", "--",
                  "he", " ", "was", " ", "gone"]
259
        self.check_split(text, expect)
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
    def test_unix_options (self):
        # Test that Unix-style command-line options are wrapped correctly.
        # Both Optik (OptionParser) and Docutils rely on this behaviour!

        text = "You should use the -n option, or --dry-run in its long form."
        self.check_wrap(text, 20,
                        ["You should use the",
                         "-n option, or --dry-",
                         "run in its long",
                         "form."])
        self.check_wrap(text, 21,
                        ["You should use the -n",
                         "option, or --dry-run",
                         "in its long form."])
        expect = ["You should use the -n option, or",
                  "--dry-run in its long form."]
        self.check_wrap(text, 32, expect)
        self.check_wrap(text, 34, expect)
        self.check_wrap(text, 35, expect)
        self.check_wrap(text, 38, expect)
        expect = ["You should use the -n option, or --dry-",
                  "run in its long form."]
        self.check_wrap(text, 39, expect)
        self.check_wrap(text, 41, expect)
        expect = ["You should use the -n option, or --dry-run",
                  "in its long form."]
        self.check_wrap(text, 42, expect)

290 291 292 293
        # Again, all of the above can be deduced from _split().
        text = "the -n option, or --dry-run or --dryrun"
        expect = ["the", " ", "-n", " ", "option,", " ", "or", " ",
                  "--dry-", "run", " ", "or", " ", "--dryrun"]
294 295 296 297 298 299 300 301 302 303
        self.check_split(text, expect)

    def test_funky_hyphens (self):
        # Screwy edge cases cooked up by David Goodger.  All reported
        # in SF bug #596434.
        self.check_split("what the--hey!", ["what", " ", "the", "--", "hey!"])
        self.check_split("what the--", ["what", " ", "the--"])
        self.check_split("what the--.", ["what", " ", "the--."])
        self.check_split("--text--.", ["--text--."])

304 305 306 307
        # When I first read bug #596434, this is what I thought David
        # was talking about.  I was wrong; these have always worked
        # fine.  The real problem is tested in test_funky_parens()
        # below...
308 309
        self.check_split("--option", ["--option"])
        self.check_split("--option-opt", ["--option-", "opt"])
310 311 312
        self.check_split("foo --option-opt bar",
                         ["foo", " ", "--option-", "opt", " ", "bar"])

313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329
    def test_punct_hyphens(self):
        # Oh bother, SF #965425 found another problem with hyphens --
        # hyphenated words in single quotes weren't handled correctly.
        # In fact, the bug is that *any* punctuation around a hyphenated
        # word was handled incorrectly, except for a leading "--", which
        # was special-cased for Optik and Docutils.  So test a variety
        # of styles of punctuation around a hyphenated word.
        # (Actually this is based on an Optik bug report, #813077).
        self.check_split("the 'wibble-wobble' widget",
                         ['the', ' ', "'wibble-", "wobble'", ' ', 'widget'])
        self.check_split('the "wibble-wobble" widget',
                         ['the', ' ', '"wibble-', 'wobble"', ' ', 'widget'])
        self.check_split("the (wibble-wobble) widget",
                         ['the', ' ', "(wibble-", "wobble)", ' ', 'widget'])
        self.check_split("the ['wibble-wobble'] widget",
                         ['the', ' ', "['wibble-", "wobble']", ' ', 'widget'])

330 331 332 333 334 335 336 337 338 339 340 341
    def test_funky_parens (self):
        # Second part of SF bug #596434: long option strings inside
        # parentheses.
        self.check_split("foo (--option) bar",
                         ["foo", " ", "(--option)", " ", "bar"])

        # Related stuff -- make sure parens work in simpler contexts.
        self.check_split("foo (bar) baz",
                         ["foo", " ", "(bar)", " ", "baz"])
        self.check_split("blah (ding dong), wubba",
                         ["blah", " ", "(ding", " ", "dong),",
                          " ", "wubba"])
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
    def test_drop_whitespace_false(self):
        # Check that drop_whitespace=False preserves whitespace.
        # SF patch #1581073
        text = " This is a    sentence with     much whitespace."
        self.check_wrap(text, 10,
                        [" This is a", "    ", "sentence ",
                         "with     ", "much white", "space."],
                        drop_whitespace=False)

    def test_drop_whitespace_false_whitespace_only(self):
        # Check that drop_whitespace=False preserves a whitespace-only string.
        self.check_wrap("   ", 6, ["   "], drop_whitespace=False)

    def test_drop_whitespace_false_whitespace_only_with_indent(self):
        # Check that a whitespace-only string gets indented (when
        # drop_whitespace is False).
        self.check_wrap("   ", 6, ["     "], drop_whitespace=False,
                        initial_indent="  ")

    def test_drop_whitespace_whitespace_only(self):
        # Check drop_whitespace on a whitespace-only string.
        self.check_wrap("  ", 6, [])

    def test_drop_whitespace_leading_whitespace(self):
        # Check that drop_whitespace does not drop leading whitespace (if
        # followed by non-whitespace).
369 370 371 372 373 374 375 376
        # SF bug #622849 reported inconsistent handling of leading
        # whitespace; let's test that a bit, shall we?
        text = " This is a sentence with leading whitespace."
        self.check_wrap(text, 50,
                        [" This is a sentence with leading whitespace."])
        self.check_wrap(text, 30,
                        [" This is a sentence with", "leading whitespace."])

377 378 379 380 381 382
    def test_drop_whitespace_whitespace_line(self):
        # Check that drop_whitespace skips the whole line if a non-leading
        # line consists only of whitespace.
        text = "abcd    efgh"
        # Include the result for drop_whitespace=False for comparison.
        self.check_wrap(text, 6, ["abcd", "    ", "efgh"],
383
                        drop_whitespace=False)
384 385 386 387 388 389 390 391 392 393 394 395 396 397
        self.check_wrap(text, 6, ["abcd", "efgh"])

    def test_drop_whitespace_whitespace_only_with_indent(self):
        # Check that initial_indent is not applied to a whitespace-only
        # string.  This checks a special case of the fact that dropping
        # whitespace occurs before indenting.
        self.check_wrap("  ", 6, [], initial_indent="++")

    def test_drop_whitespace_whitespace_indent(self):
        # Check that drop_whitespace does not drop whitespace indents.
        # This checks a special case of the fact that dropping whitespace
        # occurs before indenting.
        self.check_wrap("abcd efgh", 6, ["  abcd", "  efgh"],
                        initial_indent="  ", subsequent_indent="  ")
398

399
    def test_split(self):
400 401
        # Ensure that the standard _split() method works as advertised
        # in the comments
402

403
        text = "Hello there -- you goof-ball, use the -b option!"
404

405
        result = self.wrapper._split(text)
406 407 408 409
        self.check(result,
             ["Hello", " ", "there", " ", "--", " ", "you", " ", "goof-",
              "ball,", " ", "use", " ", "the", " ", "-b", " ",  "option!"])

410 411 412 413 414 415 416 417
    def test_break_on_hyphens(self):
        # Ensure that the break_on_hyphens attributes work
        text = "yaba daba-doo"
        self.check_wrap(text, 10, ["yaba daba-", "doo"],
                        break_on_hyphens=True)
        self.check_wrap(text, 10, ["yaba", "daba-doo"],
                        break_on_hyphens=False)

418 419 420 421 422 423
    def test_bad_width(self):
        # Ensure that width <= 0 is caught.
        text = "Whatever, it doesn't matter."
        self.assertRaises(ValueError, wrap, text, 0)
        self.assertRaises(ValueError, wrap, text, -1)

424 425 426 427 428 429 430 431
    def test_no_split_at_umlaut(self):
        text = "Die Empf\xe4nger-Auswahl"
        self.check_wrap(text, 13, ["Die", "Empf\xe4nger-", "Auswahl"])

    def test_umlaut_followed_by_dash(self):
        text = "aa \xe4\xe4-\xe4\xe4"
        self.check_wrap(text, 7, ["aa \xe4\xe4-", "\xe4\xe4"])

432

433 434 435
class LongWordTestCase (BaseTestCase):
    def setUp(self):
        self.wrapper = TextWrapper()
436
        self.text = '''\
437 438 439
Did you say "supercalifragilisticexpialidocious?"
How *do* you spell that odd word, anyways?
'''
440 441

    def test_break_long(self):
442
        # Wrap text with long words and lots of punctuation
443 444

        self.check_wrap(self.text, 30,
445 446 447 448
                        ['Did you say "supercalifragilis',
                         'ticexpialidocious?" How *do*',
                         'you spell that odd word,',
                         'anyways?'])
449
        self.check_wrap(self.text, 50,
450 451
                        ['Did you say "supercalifragilisticexpialidocious?"',
                         'How *do* you spell that odd word, anyways?'])
452

453 454 455 456 457 458 459 460 461 462
        # SF bug 797650.  Prevent an infinite loop by making sure that at
        # least one character gets split off on every pass.
        self.check_wrap('-'*10+'hello', 10,
                        ['----------',
                         '               h',
                         '               e',
                         '               l',
                         '               l',
                         '               o'],
                        subsequent_indent = ' '*15)
463

464 465 466 467 468 469 470 471 472 473 474 475 476
        # bug 1146.  Prevent a long word to be wrongly wrapped when the
        # preceding word is exactly one character shorter than the width
        self.check_wrap(self.text, 12,
                        ['Did you say ',
                         '"supercalifr',
                         'agilisticexp',
                         'ialidocious?',
                         '" How *do*',
                         'you spell',
                         'that odd',
                         'word,',
                         'anyways?'])

477 478
    def test_nobreak_long(self):
        # Test with break_long_words disabled
479 480
        self.wrapper.break_long_words = 0
        self.wrapper.width = 30
481 482 483 484
        expect = ['Did you say',
                  '"supercalifragilisticexpialidocious?"',
                  'How *do* you spell that odd',
                  'word, anyways?'
485
                  ]
486
        result = self.wrapper.wrap(self.text)
487 488 489
        self.check(result, expect)

        # Same thing with kwargs passed to standalone wrap() function.
490
        result = wrap(self.text, width=30, break_long_words=0)
491 492 493
        self.check(result, expect)


494
class IndentTestCases(BaseTestCase):
495 496 497

    # called before each test method
    def setUp(self):
498
        self.text = '''\
499 500 501 502
This paragraph will be filled, first without any indentation,
and then with some (including a hanging indent).'''


503
    def test_fill(self):
504
        # Test the fill() method
505 506 507 508 509 510

        expect = '''\
This paragraph will be filled, first
without any indentation, and then with
some (including a hanging indent).'''

511
        result = fill(self.text, 40)
512 513 514
        self.check(result, expect)


515
    def test_initial_indent(self):
516
        # Test initial_indent parameter
517

518 519 520 521
        expect = ["     This paragraph will be filled,",
                  "first without any indentation, and then",
                  "with some (including a hanging indent)."]
        result = wrap(self.text, 40, initial_indent="     ")
522 523
        self.check(result, expect)

524 525
        expect = "\n".join(expect)
        result = fill(self.text, 40, initial_indent="     ")
526 527 528
        self.check(result, expect)


529
    def test_subsequent_indent(self):
530
        # Test subsequent_indent parameter
531 532 533 534 535 536 537

        expect = '''\
  * This paragraph will be filled, first
    without any indentation, and then
    with some (including a hanging
    indent).'''

538 539
        result = fill(self.text, 40,
                      initial_indent="  * ", subsequent_indent="    ")
540 541 542
        self.check(result, expect)


543 544 545 546
# Despite the similar names, DedentTestCase is *not* the inverse
# of IndentTestCase!
class DedentTestCase(unittest.TestCase):

547 548
    def assertUnchanged(self, text):
        """assert that dedent() has no effect on 'text'"""
549
        self.assertEqual(text, dedent(text))
550

551 552 553
    def test_dedent_nomargin(self):
        # No lines indented.
        text = "Hello there.\nHow are you?\nOh good, I'm glad."
554
        self.assertUnchanged(text)
555 556 557

        # Similar, with a blank line.
        text = "Hello there.\n\nBoo!"
558
        self.assertUnchanged(text)
559 560 561

        # Some lines indented, but overall margin is still zero.
        text = "Hello there.\n  This is indented."
562
        self.assertUnchanged(text)
563 564 565

        # Again, add a blank line.
        text = "Hello there.\n\n  Boo!\n"
566
        self.assertUnchanged(text)
567 568 569 570 571

    def test_dedent_even(self):
        # All lines indented by two spaces.
        text = "  Hello there.\n  How are ya?\n  Oh good."
        expect = "Hello there.\nHow are ya?\nOh good."
572
        self.assertEqual(expect, dedent(text))
573 574 575 576

        # Same, with blank lines.
        text = "  Hello there.\n\n  How are ya?\n  Oh good.\n"
        expect = "Hello there.\n\nHow are ya?\nOh good.\n"
577
        self.assertEqual(expect, dedent(text))
578 579 580 581

        # Now indent one of the blank lines.
        text = "  Hello there.\n  \n  How are ya?\n  Oh good.\n"
        expect = "Hello there.\n\nHow are ya?\nOh good.\n"
582
        self.assertEqual(expect, dedent(text))
583 584 585 586 587 588 589 590 591 592 593 594 595

    def test_dedent_uneven(self):
        # Lines indented unevenly.
        text = '''\
        def foo():
            while 1:
                return foo
        '''
        expect = '''\
def foo():
    while 1:
        return foo
'''
596
        self.assertEqual(expect, dedent(text))
597 598 599 600

        # Uneven indentation with a blank line.
        text = "  Foo\n    Bar\n\n   Baz\n"
        expect = "Foo\n  Bar\n\n Baz\n"
601
        self.assertEqual(expect, dedent(text))
602 603 604 605

        # Uneven indentation with a whitespace-only line.
        text = "  Foo\n    Bar\n \n   Baz\n"
        expect = "Foo\n  Bar\n\n Baz\n"
606
        self.assertEqual(expect, dedent(text))
607 608 609 610 611

    # dedent() should not mangle internal tabs
    def test_dedent_preserve_internal_tabs(self):
        text = "  hello\tthere\n  how are\tyou?"
        expect = "hello\tthere\nhow are\tyou?"
612
        self.assertEqual(expect, dedent(text))
613 614 615

        # make sure that it preserves tabs when it's not making any
        # changes at all
616
        self.assertEqual(expect, dedent(expect))
617 618 619 620 621 622 623 624 625 626 627 628 629 630 631

    # dedent() should not mangle tabs in the margin (i.e.
    # tabs and spaces both count as margin, but are *not*
    # considered equivalent)
    def test_dedent_preserve_margin_tabs(self):
        text = "  hello there\n\thow are you?"
        self.assertUnchanged(text)

        # same effect even if we have 8 spaces
        text = "        hello there\n\thow are you?"
        self.assertUnchanged(text)

        # dedent() only removes whitespace that can be uniformly removed!
        text = "\thello there\n\thow are you?"
        expect = "hello there\nhow are you?"
632
        self.assertEqual(expect, dedent(text))
633 634

        text = "  \thello there\n  \thow are you?"
635
        self.assertEqual(expect, dedent(text))
636 637

        text = "  \t  hello there\n  \t  how are you?"
638
        self.assertEqual(expect, dedent(text))
639 640 641

        text = "  \thello there\n  \t  how are you?"
        expect = "hello there\n  how are you?"
642
        self.assertEqual(expect, dedent(text))
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
# Test textwrap.indent
class IndentTestCase(unittest.TestCase):
    # The examples used for tests. If any of these change, the expected
    # results in the various test cases must also be updated.
    # The roundtrip cases are separate, because textwrap.dedent doesn't
    # handle Windows line endings
    ROUNDTRIP_CASES = (
      # Basic test case
      "Hi.\nThis is a test.\nTesting.",
      # Include a blank line
      "Hi.\nThis is a test.\n\nTesting.",
      # Include leading and trailing blank lines
      "\nHi.\nThis is a test.\nTesting.\n",
    )
    CASES = ROUNDTRIP_CASES + (
      # Use Windows line endings
      "Hi.\r\nThis is a test.\r\nTesting.\r\n",
      # Pathological case
      "\nHi.\r\nThis is a test.\n\r\nTesting.\r\n\n",
    )

    def test_indent_nomargin_default(self):
        # indent should do nothing if 'prefix' is empty.
        for text in self.CASES:
            self.assertEqual(indent(text, ''), text)

    def test_indent_nomargin_explicit_default(self):
        # The same as test_indent_nomargin, but explicitly requesting
        # the default behaviour by passing None as the predicate
        for text in self.CASES:
            self.assertEqual(indent(text, '', None), text)

    def test_indent_nomargin_all_lines(self):
        # The same as test_indent_nomargin, but using the optional
        # predicate argument
        predicate = lambda line: True
        for text in self.CASES:
            self.assertEqual(indent(text, '', predicate), text)

    def test_indent_no_lines(self):
        # Explicitly skip indenting any lines
        predicate = lambda line: False
        for text in self.CASES:
            self.assertEqual(indent(text, '    ', predicate), text)

    def test_roundtrip_spaces(self):
        # A whitespace prefix should roundtrip with dedent
        for text in self.ROUNDTRIP_CASES:
            self.assertEqual(dedent(indent(text, '    ')), text)

    def test_roundtrip_tabs(self):
        # A whitespace prefix should roundtrip with dedent
        for text in self.ROUNDTRIP_CASES:
            self.assertEqual(dedent(indent(text, '\t\t')), text)

    def test_roundtrip_mixed(self):
        # A whitespace prefix should roundtrip with dedent
        for text in self.ROUNDTRIP_CASES:
            self.assertEqual(dedent(indent(text, ' \t  \t ')), text)

    def test_indent_default(self):
        # Test default indenting of lines that are not whitespace only
        prefix = '  '
        expected = (
          # Basic test case
          "  Hi.\n  This is a test.\n  Testing.",
          # Include a blank line
          "  Hi.\n  This is a test.\n\n  Testing.",
          # Include leading and trailing blank lines
          "\n  Hi.\n  This is a test.\n  Testing.\n",
          # Use Windows line endings
          "  Hi.\r\n  This is a test.\r\n  Testing.\r\n",
          # Pathological case
          "\n  Hi.\r\n  This is a test.\n\r\n  Testing.\r\n\n",
        )
        for text, expect in zip(self.CASES, expected):
            self.assertEqual(indent(text, prefix), expect)

    def test_indent_explicit_default(self):
        # Test default indenting of lines that are not whitespace only
        prefix = '  '
        expected = (
          # Basic test case
          "  Hi.\n  This is a test.\n  Testing.",
          # Include a blank line
          "  Hi.\n  This is a test.\n\n  Testing.",
          # Include leading and trailing blank lines
          "\n  Hi.\n  This is a test.\n  Testing.\n",
          # Use Windows line endings
          "  Hi.\r\n  This is a test.\r\n  Testing.\r\n",
          # Pathological case
          "\n  Hi.\r\n  This is a test.\n\r\n  Testing.\r\n\n",
        )
        for text, expect in zip(self.CASES, expected):
            self.assertEqual(indent(text, prefix, None), expect)

    def test_indent_all_lines(self):
        # Add 'prefix' to all lines, including whitespace-only ones.
        prefix = '  '
        expected = (
          # Basic test case
          "  Hi.\n  This is a test.\n  Testing.",
          # Include a blank line
          "  Hi.\n  This is a test.\n  \n  Testing.",
          # Include leading and trailing blank lines
          "  \n  Hi.\n  This is a test.\n  Testing.\n",
          # Use Windows line endings
          "  Hi.\r\n  This is a test.\r\n  Testing.\r\n",
          # Pathological case
          "  \n  Hi.\r\n  This is a test.\n  \r\n  Testing.\r\n  \n",
        )
        predicate = lambda line: True
        for text, expect in zip(self.CASES, expected):
            self.assertEqual(indent(text, prefix, predicate), expect)

    def test_indent_empty_lines(self):
        # Add 'prefix' solely to whitespace-only lines.
        prefix = '  '
        expected = (
          # Basic test case
          "Hi.\nThis is a test.\nTesting.",
          # Include a blank line
          "Hi.\nThis is a test.\n  \nTesting.",
          # Include leading and trailing blank lines
          "  \nHi.\nThis is a test.\nTesting.\n",
          # Use Windows line endings
          "Hi.\r\nThis is a test.\r\nTesting.\r\n",
          # Pathological case
          "  \nHi.\r\nThis is a test.\n  \r\nTesting.\r\n  \n",
        )
        predicate = lambda line: not line.strip()
        for text, expect in zip(self.CASES, expected):
            self.assertEqual(indent(text, prefix, predicate), expect)


780
def test_main():
781
    support.run_unittest(WrapTestCase,
782 783
                              LongWordTestCase,
                              IndentTestCases,
784 785
                              DedentTestCase,
                              IndentTestCase)
786

787
if __name__ == '__main__':
788
    test_main()