Merge branch 'tg/t-readme-updates'
[git/git.git] / t / README
1 Core GIT Tests
2 ==============
3
4 This directory holds many test scripts for core GIT tools. The
5 first part of this short document describes how to run the tests
6 and read their output.
7
8 When fixing the tools or adding enhancements, you are strongly
9 encouraged to add tests in this directory to cover what you are
10 trying to fix or enhance. The later part of this short document
11 describes how your test scripts should be organized.
12
13
14 Running Tests
15 -------------
16
17 The easiest way to run tests is to say "make". This runs all
18 the tests.
19
20 *** t0000-basic.sh ***
21 ok 1 - .git/objects should be empty after git init in an empty repo.
22 ok 2 - .git/objects should have 3 subdirectories.
23 ok 3 - success is reported like this
24 ...
25 ok 43 - very long name in the index handled sanely
26 # fixed 1 known breakage(s)
27 # still have 1 known breakage(s)
28 # passed all remaining 42 test(s)
29 1..43
30 *** t0001-init.sh ***
31 ok 1 - plain
32 ok 2 - plain with GIT_WORK_TREE
33 ok 3 - plain bare
34
35 Since the tests all output TAP (see http://testanything.org) they can
36 be run with any TAP harness. Here's an example of parallel testing
37 powered by a recent version of prove(1):
38
39 $ prove --timer --jobs 15 ./t[0-9]*.sh
40 [19:17:33] ./t0005-signals.sh ................................... ok 36 ms
41 [19:17:33] ./t0022-crlf-rename.sh ............................... ok 69 ms
42 [19:17:33] ./t0024-crlf-archive.sh .............................. ok 154 ms
43 [19:17:33] ./t0004-unwritable.sh ................................ ok 289 ms
44 [19:17:33] ./t0002-gitfile.sh ................................... ok 480 ms
45 ===( 102;0 25/? 6/? 5/? 16/? 1/? 4/? 2/? 1/? 3/? 1... )===
46
47 prove and other harnesses come with a lot of useful options. The
48 --state option in particular is very useful:
49
50 # Repeat until no more failures
51 $ prove -j 15 --state=failed,save ./t[0-9]*.sh
52
53 You can give DEFAULT_TEST_TARGET=prove on the make command (or define it
54 in config.mak) to cause "make test" to run tests under prove.
55 GIT_PROVE_OPTS can be used to pass additional options, e.g.
56
57 $ make DEFAULT_TEST_TARGET=prove GIT_PROVE_OPTS='--timer --jobs 16' test
58
59 You can also run each test individually from command line, like this:
60
61 $ sh ./t3010-ls-files-killed-modified.sh
62 ok 1 - git update-index --add to add various paths.
63 ok 2 - git ls-files -k to show killed files.
64 ok 3 - validate git ls-files -k output.
65 ok 4 - git ls-files -m to show modified files.
66 ok 5 - validate git ls-files -m output.
67 # passed all 5 test(s)
68 1..5
69
70 You can pass --verbose (or -v), --debug (or -d), and --immediate
71 (or -i) command line argument to the test, or by setting GIT_TEST_OPTS
72 appropriately before running "make".
73
74 -v::
75 --verbose::
76 This makes the test more verbose. Specifically, the
77 command being run and their output if any are also
78 output.
79
80 --verbose-only=<pattern>::
81 Like --verbose, but the effect is limited to tests with
82 numbers matching <pattern>. The number matched against is
83 simply the running count of the test within the file.
84
85 -x::
86 Turn on shell tracing (i.e., `set -x`) during the tests
87 themselves. Implies `--verbose`. Note that in non-bash shells,
88 this can cause failures in some tests which redirect and test
89 the output of shell functions. Use with caution.
90
91 -d::
92 --debug::
93 This may help the person who is developing a new test.
94 It causes the command defined with test_debug to run.
95 The "trash" directory (used to store all temporary data
96 during testing) is not deleted even if there are no
97 failed tests so that you can inspect its contents after
98 the test finished.
99
100 -i::
101 --immediate::
102 This causes the test to immediately exit upon the first
103 failed test. Cleanup commands requested with
104 test_when_finished are not executed if the test failed,
105 in order to keep the state for inspection by the tester
106 to diagnose the bug.
107
108 -l::
109 --long-tests::
110 This causes additional long-running tests to be run (where
111 available), for more exhaustive testing.
112
113 -r::
114 --run=<test-selector>::
115 Run only the subset of tests indicated by
116 <test-selector>. See section "Skipping Tests" below for
117 <test-selector> syntax.
118
119 --valgrind=<tool>::
120 Execute all Git binaries under valgrind tool <tool> and exit
121 with status 126 on errors (just like regular tests, this will
122 only stop the test script when running under -i).
123
124 Since it makes no sense to run the tests with --valgrind and
125 not see any output, this option implies --verbose. For
126 convenience, it also implies --tee.
127
128 <tool> defaults to 'memcheck', just like valgrind itself.
129 Other particularly useful choices include 'helgrind' and
130 'drd', but you may use any tool recognized by your valgrind
131 installation.
132
133 As a special case, <tool> can be 'memcheck-fast', which uses
134 memcheck but disables --track-origins. Use this if you are
135 running tests in bulk, to see if there are _any_ memory
136 issues.
137
138 Note that memcheck is run with the option --leak-check=no,
139 as the git process is short-lived and some errors are not
140 interesting. In order to run a single command under the same
141 conditions manually, you should set GIT_VALGRIND to point to
142 the 't/valgrind/' directory and use the commands under
143 't/valgrind/bin/'.
144
145 --valgrind-only=<pattern>::
146 Like --valgrind, but the effect is limited to tests with
147 numbers matching <pattern>. The number matched against is
148 simply the running count of the test within the file.
149
150 --tee::
151 In addition to printing the test output to the terminal,
152 write it to files named 't/test-results/$TEST_NAME.out'.
153 As the names depend on the tests' file names, it is safe to
154 run the tests with this option in parallel.
155
156 --verbose-log::
157 Write verbose output to the same logfile as `--tee`, but do
158 _not_ write it to stdout. Unlike `--tee --verbose`, this option
159 is safe to use when stdout is being consumed by a TAP parser
160 like `prove`. Implies `--tee` and `--verbose`.
161
162 --with-dashes::
163 By default tests are run without dashed forms of
164 commands (like git-commit) in the PATH (it only uses
165 wrappers from ../bin-wrappers). Use this option to include
166 the build directory (..) in the PATH, which contains all
167 the dashed forms of commands. This option is currently
168 implied by other options like --valgrind and
169 GIT_TEST_INSTALLED.
170
171 --root=<directory>::
172 Create "trash" directories used to store all temporary data during
173 testing under <directory>, instead of the t/ directory.
174 Using this option with a RAM-based filesystem (such as tmpfs)
175 can massively speed up the test suite.
176
177 --chain-lint::
178 --no-chain-lint::
179 If --chain-lint is enabled, the test harness will check each
180 test to make sure that it properly "&&-chains" all commands (so
181 that a failure in the middle does not go unnoticed by the final
182 exit code of the test). This check is performed in addition to
183 running the tests themselves. You may also enable or disable
184 this feature by setting the GIT_TEST_CHAIN_LINT environment
185 variable to "1" or "0", respectively.
186
187 You can also set the GIT_TEST_INSTALLED environment variable to
188 the bindir of an existing git installation to test that installation.
189 You still need to have built this git sandbox, from which various
190 test-* support programs, templates, and perl libraries are used.
191 If your installed git is incomplete, it will silently test parts of
192 your built version instead.
193
194 When using GIT_TEST_INSTALLED, you can also set GIT_TEST_EXEC_PATH to
195 override the location of the dashed-form subcommands (what
196 GIT_EXEC_PATH would be used for during normal operation).
197 GIT_TEST_EXEC_PATH defaults to `$GIT_TEST_INSTALLED/git --exec-path`.
198
199
200 Skipping Tests
201 --------------
202
203 In some environments, certain tests have no way of succeeding
204 due to platform limitation, such as lack of 'unzip' program, or
205 filesystem that do not allow arbitrary sequence of non-NUL bytes
206 as pathnames.
207
208 You should be able to say something like
209
210 $ GIT_SKIP_TESTS=t9200.8 sh ./t9200-git-cvsexport-commit.sh
211
212 and even:
213
214 $ GIT_SKIP_TESTS='t[0-4]??? t91?? t9200.8' make
215
216 to omit such tests. The value of the environment variable is a
217 SP separated list of patterns that tells which tests to skip,
218 and either can match the "t[0-9]{4}" part to skip the whole
219 test, or t[0-9]{4} followed by ".$number" to say which
220 particular test to skip.
221
222 For an individual test suite --run could be used to specify that
223 only some tests should be run or that some tests should be
224 excluded from a run.
225
226 The argument for --run is a list of individual test numbers or
227 ranges with an optional negation prefix that define what tests in
228 a test suite to include in the run. A range is two numbers
229 separated with a dash and matches a range of tests with both ends
230 been included. You may omit the first or the second number to
231 mean "from the first test" or "up to the very last test"
232 respectively.
233
234 Optional prefix of '!' means that the test or a range of tests
235 should be excluded from the run.
236
237 If --run starts with an unprefixed number or range the initial
238 set of tests to run is empty. If the first item starts with '!'
239 all the tests are added to the initial set. After initial set is
240 determined every test number or range is added or excluded from
241 the set one by one, from left to right.
242
243 Individual numbers or ranges could be separated either by a space
244 or a comma.
245
246 For example, to run only tests up to a specific test (21), one
247 could do this:
248
249 $ sh ./t9200-git-cvsexport-commit.sh --run='1-21'
250
251 or this:
252
253 $ sh ./t9200-git-cvsexport-commit.sh --run='-21'
254
255 Common case is to run several setup tests (1, 2, 3) and then a
256 specific test (21) that relies on that setup:
257
258 $ sh ./t9200-git-cvsexport-commit.sh --run='1 2 3 21'
259
260 or:
261
262 $ sh ./t9200-git-cvsexport-commit.sh --run=1,2,3,21
263
264 or:
265
266 $ sh ./t9200-git-cvsexport-commit.sh --run='-3 21'
267
268 As noted above, the test set is built by going through the items
269 from left to right, so this:
270
271 $ sh ./t9200-git-cvsexport-commit.sh --run='1-4 !3'
272
273 will run tests 1, 2, and 4. Items that come later have higher
274 precedence. It means that this:
275
276 $ sh ./t9200-git-cvsexport-commit.sh --run='!3 1-4'
277
278 would just run tests from 1 to 4, including 3.
279
280 You may use negation with ranges. The following will run all
281 test in the test suite except from 7 up to 11:
282
283 $ sh ./t9200-git-cvsexport-commit.sh --run='!7-11'
284
285 Some tests in a test suite rely on the previous tests performing
286 certain actions, specifically some tests are designated as
287 "setup" test, so you cannot _arbitrarily_ disable one test and
288 expect the rest to function correctly.
289
290 --run is mostly useful when you want to focus on a specific test
291 and know what setup is needed for it. Or when you want to run
292 everything up to a certain test.
293
294
295 Naming Tests
296 ------------
297
298 The test files are named as:
299
300 tNNNN-commandname-details.sh
301
302 where N is a decimal digit.
303
304 First digit tells the family:
305
306 0 - the absolute basics and global stuff
307 1 - the basic commands concerning database
308 2 - the basic commands concerning the working tree
309 3 - the other basic commands (e.g. ls-files)
310 4 - the diff commands
311 5 - the pull and exporting commands
312 6 - the revision tree commands (even e.g. merge-base)
313 7 - the porcelainish commands concerning the working tree
314 8 - the porcelainish commands concerning forensics
315 9 - the git tools
316
317 Second digit tells the particular command we are testing.
318
319 Third digit (optionally) tells the particular switch or group of switches
320 we are testing.
321
322 If you create files under t/ directory (i.e. here) that is not
323 the top-level test script, never name the file to match the above
324 pattern. The Makefile here considers all such files as the
325 top-level test script and tries to run all of them. Care is
326 especially needed if you are creating a common test library
327 file, similar to test-lib.sh, because such a library file may
328 not be suitable for standalone execution.
329
330
331 Writing Tests
332 -------------
333
334 The test script is written as a shell script. It should start
335 with the standard "#!/bin/sh", and an
336 assignment to variable 'test_description', like this:
337
338 #!/bin/sh
339
340 test_description='xxx test (option --frotz)
341
342 This test registers the following structure in the cache
343 and tries to run git-ls-files with option --frotz.'
344
345
346 Source 'test-lib.sh'
347 --------------------
348
349 After assigning test_description, the test script should source
350 test-lib.sh like this:
351
352 . ./test-lib.sh
353
354 This test harness library does the following things:
355
356 - If the script is invoked with command line argument --help
357 (or -h), it shows the test_description and exits.
358
359 - Creates an empty test directory with an empty .git/objects database
360 and chdir(2) into it. This directory is 't/trash
361 directory.$test_name_without_dotsh', with t/ subject to change by
362 the --root option documented above.
363
364 - Defines standard test helper functions for your scripts to
365 use. These functions are designed to make all scripts behave
366 consistently when command line arguments --verbose (or -v),
367 --debug (or -d), and --immediate (or -i) is given.
368
369 Do's, don'ts & things to keep in mind
370 -------------------------------------
371
372 Here are a few examples of things you probably should and shouldn't do
373 when writing tests.
374
375 Do:
376
377 - Put all code inside test_expect_success and other assertions.
378
379 Even code that isn't a test per se, but merely some setup code
380 should be inside a test assertion.
381
382 - Chain your test assertions
383
384 Write test code like this:
385
386 git merge foo &&
387 git push bar &&
388 test ...
389
390 Instead of:
391
392 git merge hla
393 git push gh
394 test ...
395
396 That way all of the commands in your tests will succeed or fail. If
397 you must ignore the return value of something, consider using a
398 helper function (e.g. use sane_unset instead of unset, in order
399 to avoid unportable return value for unsetting a variable that was
400 already unset), or prepending the command with test_might_fail or
401 test_must_fail.
402
403 - Check the test coverage for your tests. See the "Test coverage"
404 below.
405
406 Don't blindly follow test coverage metrics; if a new function you added
407 doesn't have any coverage, then you're probably doing something wrong,
408 but having 100% coverage doesn't necessarily mean that you tested
409 everything.
410
411 Tests that are likely to smoke out future regressions are better
412 than tests that just inflate the coverage metrics.
413
414 - When a test checks for an absolute path that a git command generated,
415 construct the expected value using $(pwd) rather than $PWD,
416 $TEST_DIRECTORY, or $TRASH_DIRECTORY. It makes a difference on
417 Windows, where the shell (MSYS bash) mangles absolute path names.
418 For details, see the commit message of 4114156ae9.
419
420 Don't:
421
422 - exit() within a <script> part.
423
424 The harness will catch this as a programming error of the test.
425 Use test_done instead if you need to stop the tests early (see
426 "Skipping tests" below).
427
428 - use '! git cmd' when you want to make sure the git command exits
429 with failure in a controlled way by calling "die()". Instead,
430 use 'test_must_fail git cmd'. This will signal a failure if git
431 dies in an unexpected way (e.g. segfault).
432
433 On the other hand, don't use test_must_fail for running regular
434 platform commands; just use '! cmd'. We are not in the business
435 of verifying that the world given to us sanely works.
436
437 - use perl without spelling it as "$PERL_PATH". This is to help our
438 friends on Windows where the platform Perl often adds CR before
439 the end of line, and they bundle Git with a version of Perl that
440 does not do so, whose path is specified with $PERL_PATH. Note that we
441 provide a "perl" function which uses $PERL_PATH under the hood, so
442 you do not need to worry when simply running perl in the test scripts
443 (but you do, for example, on a shebang line or in a sub script
444 created via "write_script").
445
446 - use sh without spelling it as "$SHELL_PATH", when the script can
447 be misinterpreted by broken platform shell (e.g. Solaris).
448
449 - chdir around in tests. It is not sufficient to chdir to
450 somewhere and then chdir back to the original location later in
451 the test, as any intermediate step can fail and abort the test,
452 causing the next test to start in an unexpected directory. Do so
453 inside a subshell if necessary.
454
455 - Break the TAP output
456
457 The raw output from your test may be interpreted by a TAP harness. TAP
458 harnesses will ignore everything they don't know about, but don't step
459 on their toes in these areas:
460
461 - Don't print lines like "$x..$y" where $x and $y are integers.
462
463 - Don't print lines that begin with "ok" or "not ok".
464
465 TAP harnesses expect a line that begins with either "ok" and "not
466 ok" to signal a test passed or failed (and our harness already
467 produces such lines), so your script shouldn't emit such lines to
468 their output.
469
470 You can glean some further possible issues from the TAP grammar
471 (see https://metacpan.org/pod/TAP::Parser::Grammar#TAP-GRAMMAR)
472 but the best indication is to just run the tests with prove(1),
473 it'll complain if anything is amiss.
474
475 Keep in mind:
476
477 - Inside the <script> part, the standard output and standard error
478 streams are discarded, and the test harness only reports "ok" or
479 "not ok" to the end user running the tests. Under --verbose, they
480 are shown to help debugging the tests.
481
482
483 Skipping tests
484 --------------
485
486 If you need to skip tests you should do so by using the three-arg form
487 of the test_* functions (see the "Test harness library" section
488 below), e.g.:
489
490 test_expect_success PERL 'I need Perl' '
491 perl -e "hlagh() if unf_unf()"
492 '
493
494 The advantage of skipping tests like this is that platforms that don't
495 have the PERL and other optional dependencies get an indication of how
496 many tests they're missing.
497
498 If the test code is too hairy for that (i.e. does a lot of setup work
499 outside test assertions) you can also skip all remaining tests by
500 setting skip_all and immediately call test_done:
501
502 if ! test_have_prereq PERL
503 then
504 skip_all='skipping perl interface tests, perl not available'
505 test_done
506 fi
507
508 The string you give to skip_all will be used as an explanation for why
509 the test was skipped.
510
511 End with test_done
512 ------------------
513
514 Your script will be a sequence of tests, using helper functions
515 from the test harness library. At the end of the script, call
516 'test_done'.
517
518
519 Test harness library
520 --------------------
521
522 There are a handful helper functions defined in the test harness
523 library for your script to use.
524
525 - test_expect_success [<prereq>] <message> <script>
526
527 Usually takes two strings as parameters, and evaluates the
528 <script>. If it yields success, test is considered
529 successful. <message> should state what it is testing.
530
531 Example:
532
533 test_expect_success \
534 'git-write-tree should be able to write an empty tree.' \
535 'tree=$(git-write-tree)'
536
537 If you supply three parameters the first will be taken to be a
538 prerequisite; see the test_set_prereq and test_have_prereq
539 documentation below:
540
541 test_expect_success TTY 'git --paginate rev-list uses a pager' \
542 ' ... '
543
544 You can also supply a comma-separated list of prerequisites, in the
545 rare case where your test depends on more than one:
546
547 test_expect_success PERL,PYTHON 'yo dawg' \
548 ' test $(perl -E 'print eval "1 +" . qx[python -c "print 2"]') == "4" '
549
550 - test_expect_failure [<prereq>] <message> <script>
551
552 This is NOT the opposite of test_expect_success, but is used
553 to mark a test that demonstrates a known breakage. Unlike
554 the usual test_expect_success tests, which say "ok" on
555 success and "FAIL" on failure, this will say "FIXED" on
556 success and "still broken" on failure. Failures from these
557 tests won't cause -i (immediate) to stop.
558
559 Like test_expect_success this function can optionally use a three
560 argument invocation with a prerequisite as the first argument.
561
562 - test_debug <script>
563
564 This takes a single argument, <script>, and evaluates it only
565 when the test script is started with --debug command line
566 argument. This is primarily meant for use during the
567 development of a new test script.
568
569 - debug <git-command>
570
571 Run a git command inside a debugger. This is primarily meant for
572 use when debugging a failing test script.
573
574 - test_done
575
576 Your test script must have test_done at the end. Its purpose
577 is to summarize successes and failures in the test script and
578 exit with an appropriate error code.
579
580 - test_tick
581
582 Make commit and tag names consistent by setting the author and
583 committer times to defined state. Subsequent calls will
584 advance the times by a fixed amount.
585
586 - test_commit <message> [<filename> [<contents>]]
587
588 Creates a commit with the given message, committing the given
589 file with the given contents (default for both is to reuse the
590 message string), and adds a tag (again reusing the message
591 string as name). Calls test_tick to make the SHA-1s
592 reproducible.
593
594 - test_merge <message> <commit-or-tag>
595
596 Merges the given rev using the given message. Like test_commit,
597 creates a tag and calls test_tick before committing.
598
599 - test_set_prereq <prereq>
600
601 Set a test prerequisite to be used later with test_have_prereq. The
602 test-lib will set some prerequisites for you, see the
603 "Prerequisites" section below for a full list of these.
604
605 Others you can set yourself and use later with either
606 test_have_prereq directly, or the three argument invocation of
607 test_expect_success and test_expect_failure.
608
609 - test_have_prereq <prereq>
610
611 Check if we have a prerequisite previously set with test_set_prereq.
612 The most common way to use this explicitly (as opposed to the
613 implicit use when an argument is passed to test_expect_*) is to skip
614 all the tests at the start of the test script if we don't have some
615 essential prerequisite:
616
617 if ! test_have_prereq PERL
618 then
619 skip_all='skipping perl interface tests, perl not available'
620 test_done
621 fi
622
623 - test_external [<prereq>] <message> <external> <script>
624
625 Execute a <script> with an <external> interpreter (like perl). This
626 was added for tests like t9700-perl-git.sh which do most of their
627 work in an external test script.
628
629 test_external \
630 'GitwebCache::*FileCache*' \
631 perl "$TEST_DIRECTORY"/t9503/test_cache_interface.pl
632
633 If the test is outputting its own TAP you should set the
634 test_external_has_tap variable somewhere before calling the first
635 test_external* function. See t9700-perl-git.sh for an example.
636
637 # The external test will outputs its own plan
638 test_external_has_tap=1
639
640 - test_external_without_stderr [<prereq>] <message> <external> <script>
641
642 Like test_external but fail if there's any output on stderr,
643 instead of checking the exit code.
644
645 test_external_without_stderr \
646 'Perl API' \
647 perl "$TEST_DIRECTORY"/t9700/test.pl
648
649 - test_expect_code <exit-code> <command>
650
651 Run a command and ensure that it exits with the given exit code.
652 For example:
653
654 test_expect_success 'Merge with d/f conflicts' '
655 test_expect_code 1 git merge "merge msg" B master
656 '
657
658 - test_must_fail <git-command>
659
660 Run a git command and ensure it fails in a controlled way. Use
661 this instead of "! <git-command>". When git-command dies due to a
662 segfault, test_must_fail diagnoses it as an error; "! <git-command>"
663 treats it as just another expected failure, which would let such a
664 bug go unnoticed.
665
666 - test_might_fail <git-command>
667
668 Similar to test_must_fail, but tolerate success, too. Use this
669 instead of "<git-command> || :" to catch failures due to segv.
670
671 - test_cmp <expected> <actual>
672
673 Check whether the content of the <actual> file matches the
674 <expected> file. This behaves like "cmp" but produces more
675 helpful output when the test is run with "-v" option.
676
677 - test_cmp_rev <expected> <actual>
678
679 Check whether the <expected> rev points to the same commit as the
680 <actual> rev.
681
682 - test_line_count (= | -lt | -ge | ...) <length> <file>
683
684 Check whether a file has the length it is expected to.
685
686 - test_path_is_file <path> [<diagnosis>]
687 test_path_is_dir <path> [<diagnosis>]
688 test_path_is_missing <path> [<diagnosis>]
689
690 Check if the named path is a file, if the named path is a
691 directory, or if the named path does not exist, respectively,
692 and fail otherwise, showing the <diagnosis> text.
693
694 - test_when_finished <script>
695
696 Prepend <script> to a list of commands to run to clean up
697 at the end of the current test. If some clean-up command
698 fails, the test will not pass.
699
700 Example:
701
702 test_expect_success 'branch pointing to non-commit' '
703 git rev-parse HEAD^{tree} >.git/refs/heads/invalid &&
704 test_when_finished "git update-ref -d refs/heads/invalid" &&
705 ...
706 '
707
708 - test_write_lines <lines>
709
710 Write <lines> on standard output, one line per argument.
711 Useful to prepare multi-line files in a compact form.
712
713 Example:
714
715 test_write_lines a b c d e f g >foo
716
717 Is a more compact equivalent of:
718 cat >foo <<-EOF
719 a
720 b
721 c
722 d
723 e
724 f
725 g
726 EOF
727
728
729 - test_pause
730
731 This command is useful for writing and debugging tests and must be
732 removed before submitting. It halts the execution of the test and
733 spawns a shell in the trash directory. Exit the shell to continue
734 the test. Example:
735
736 test_expect_success 'test' '
737 git do-something >actual &&
738 test_pause &&
739 test_cmp expected actual
740 '
741
742 - test_ln_s_add <path1> <path2>
743
744 This function helps systems whose filesystem does not support symbolic
745 links. Use it to add a symbolic link entry to the index when it is not
746 important that the file system entry is a symbolic link, i.e., instead
747 of the sequence
748
749 ln -s foo bar &&
750 git add bar
751
752 Sometimes it is possible to split a test in a part that does not need
753 the symbolic link in the file system and a part that does; then only
754 the latter part need be protected by a SYMLINKS prerequisite (see below).
755
756 Prerequisites
757 -------------
758
759 These are the prerequisites that the test library predefines with
760 test_have_prereq.
761
762 See the prereq argument to the test_* functions in the "Test harness
763 library" section above and the "test_have_prereq" function for how to
764 use these, and "test_set_prereq" for how to define your own.
765
766 - PYTHON
767
768 Git wasn't compiled with NO_PYTHON=YesPlease. Wrap any tests that
769 need Python with this.
770
771 - PERL
772
773 Git wasn't compiled with NO_PERL=YesPlease.
774
775 Even without the PERL prerequisite, tests can assume there is a
776 usable perl interpreter at $PERL_PATH, though it need not be
777 particularly modern.
778
779 - POSIXPERM
780
781 The filesystem supports POSIX style permission bits.
782
783 - BSLASHPSPEC
784
785 Backslashes in pathspec are not directory separators. This is not
786 set on Windows. See 6fd1106a for details.
787
788 - EXECKEEPSPID
789
790 The process retains the same pid across exec(2). See fb9a2bea for
791 details.
792
793 - PIPE
794
795 The filesystem we're on supports creation of FIFOs (named pipes)
796 via mkfifo(1).
797
798 - SYMLINKS
799
800 The filesystem we're on supports symbolic links. E.g. a FAT
801 filesystem doesn't support these. See 704a3143 for details.
802
803 - SANITY
804
805 Test is not run by root user, and an attempt to write to an
806 unwritable file is expected to fail correctly.
807
808 - PCRE
809
810 Git was compiled with support for PCRE. Wrap any tests
811 that use git-grep --perl-regexp or git-grep -P in these.
812
813 - LIBPCRE1
814
815 Git was compiled with PCRE v1 support via
816 USE_LIBPCRE1=YesPlease. Wrap any PCRE using tests that for some
817 reason need v1 of the PCRE library instead of v2 in these.
818
819 - LIBPCRE2
820
821 Git was compiled with PCRE v2 support via
822 USE_LIBPCRE2=YesPlease. Wrap any PCRE using tests that for some
823 reason need v2 of the PCRE library instead of v1 in these.
824
825 - CASE_INSENSITIVE_FS
826
827 Test is run on a case insensitive file system.
828
829 - UTF8_NFD_TO_NFC
830
831 Test is run on a filesystem which converts decomposed utf-8 (nfd)
832 to precomposed utf-8 (nfc).
833
834 - PTHREADS
835
836 Git wasn't compiled with NO_PTHREADS=YesPlease.
837
838 Tips for Writing Tests
839 ----------------------
840
841 As with any programming projects, existing programs are the best
842 source of the information. However, do _not_ emulate
843 t0000-basic.sh when writing your tests. The test is special in
844 that it tries to validate the very core of GIT. For example, it
845 knows that there will be 256 subdirectories under .git/objects/,
846 and it knows that the object ID of an empty tree is a certain
847 40-byte string. This is deliberately done so in t0000-basic.sh
848 because the things the very basic core test tries to achieve is
849 to serve as a basis for people who are changing the GIT internal
850 drastically. For these people, after making certain changes,
851 not seeing failures from the basic test _is_ a failure. And
852 such drastic changes to the core GIT that even changes these
853 otherwise supposedly stable object IDs should be accompanied by
854 an update to t0000-basic.sh.
855
856 However, other tests that simply rely on basic parts of the core
857 GIT working properly should not have that level of intimate
858 knowledge of the core GIT internals. If all the test scripts
859 hardcoded the object IDs like t0000-basic.sh does, that defeats
860 the purpose of t0000-basic.sh, which is to isolate that level of
861 validation in one place. Your test also ends up needing
862 updating when such a change to the internal happens, so do _not_
863 do it and leave the low level of validation to t0000-basic.sh.
864
865 Test coverage
866 -------------
867
868 You can use the coverage tests to find code paths that are not being
869 used or properly exercised yet.
870
871 To do that, run the coverage target at the top-level (not in the t/
872 directory):
873
874 make coverage
875
876 That'll compile Git with GCC's coverage arguments, and generate a test
877 report with gcov after the tests finish. Running the coverage tests
878 can take a while, since running the tests in parallel is incompatible
879 with GCC's coverage mode.
880
881 After the tests have run you can generate a list of untested
882 functions:
883
884 make coverage-untested-functions
885
886 You can also generate a detailed per-file HTML report using the
887 Devel::Cover module. To install it do:
888
889 # On Debian or Ubuntu:
890 sudo aptitude install libdevel-cover-perl
891
892 # From the CPAN with cpanminus
893 curl -L http://cpanmin.us | perl - --sudo --self-upgrade
894 cpanm --sudo Devel::Cover
895
896 Then, at the top-level:
897
898 make cover_db_html
899
900 That'll generate a detailed cover report in the "cover_db_html"
901 directory, which you can then copy to a webserver, or inspect locally
902 in a browser.