25864ec88384850342f3e6122f82470424e49953
[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`.
88 Ignored in test scripts that set the variable 'test_untraceable'
89 to a non-empty value, unless it's run with a Bash version
90 supporting BASH_XTRACEFD, i.e. v4.1 or later.
91
92 -d::
93 --debug::
94 This may help the person who is developing a new test.
95 It causes the command defined with test_debug to run.
96 The "trash" directory (used to store all temporary data
97 during testing) is not deleted even if there are no
98 failed tests so that you can inspect its contents after
99 the test finished.
100
101 -i::
102 --immediate::
103 This causes the test to immediately exit upon the first
104 failed test. Cleanup commands requested with
105 test_when_finished are not executed if the test failed,
106 in order to keep the state for inspection by the tester
107 to diagnose the bug.
108
109 -l::
110 --long-tests::
111 This causes additional long-running tests to be run (where
112 available), for more exhaustive testing.
113
114 -r::
115 --run=<test-selector>::
116 Run only the subset of tests indicated by
117 <test-selector>. See section "Skipping Tests" below for
118 <test-selector> syntax.
119
120 --valgrind=<tool>::
121 Execute all Git binaries under valgrind tool <tool> and exit
122 with status 126 on errors (just like regular tests, this will
123 only stop the test script when running under -i).
124
125 Since it makes no sense to run the tests with --valgrind and
126 not see any output, this option implies --verbose. For
127 convenience, it also implies --tee.
128
129 <tool> defaults to 'memcheck', just like valgrind itself.
130 Other particularly useful choices include 'helgrind' and
131 'drd', but you may use any tool recognized by your valgrind
132 installation.
133
134 As a special case, <tool> can be 'memcheck-fast', which uses
135 memcheck but disables --track-origins. Use this if you are
136 running tests in bulk, to see if there are _any_ memory
137 issues.
138
139 Note that memcheck is run with the option --leak-check=no,
140 as the git process is short-lived and some errors are not
141 interesting. In order to run a single command under the same
142 conditions manually, you should set GIT_VALGRIND to point to
143 the 't/valgrind/' directory and use the commands under
144 't/valgrind/bin/'.
145
146 --valgrind-only=<pattern>::
147 Like --valgrind, but the effect is limited to tests with
148 numbers matching <pattern>. The number matched against is
149 simply the running count of the test within the file.
150
151 --tee::
152 In addition to printing the test output to the terminal,
153 write it to files named 't/test-results/$TEST_NAME.out'.
154 As the names depend on the tests' file names, it is safe to
155 run the tests with this option in parallel.
156
157 -V::
158 --verbose-log::
159 Write verbose output to the same logfile as `--tee`, but do
160 _not_ write it to stdout. Unlike `--tee --verbose`, this option
161 is safe to use when stdout is being consumed by a TAP parser
162 like `prove`. Implies `--tee` and `--verbose`.
163
164 --with-dashes::
165 By default tests are run without dashed forms of
166 commands (like git-commit) in the PATH (it only uses
167 wrappers from ../bin-wrappers). Use this option to include
168 the build directory (..) in the PATH, which contains all
169 the dashed forms of commands. This option is currently
170 implied by other options like --valgrind and
171 GIT_TEST_INSTALLED.
172
173 --root=<directory>::
174 Create "trash" directories used to store all temporary data during
175 testing under <directory>, instead of the t/ directory.
176 Using this option with a RAM-based filesystem (such as tmpfs)
177 can massively speed up the test suite.
178
179 --chain-lint::
180 --no-chain-lint::
181 If --chain-lint is enabled, the test harness will check each
182 test to make sure that it properly "&&-chains" all commands (so
183 that a failure in the middle does not go unnoticed by the final
184 exit code of the test). This check is performed in addition to
185 running the tests themselves. You may also enable or disable
186 this feature by setting the GIT_TEST_CHAIN_LINT environment
187 variable to "1" or "0", respectively.
188
189 --stress::
190 --stress=<N>::
191 Run the test script repeatedly in multiple parallel jobs until
192 one of them fails. Useful for reproducing rare failures in
193 flaky tests. The number of parallel jobs is, in order of
194 precedence: <N>, or the value of the GIT_TEST_STRESS_LOAD
195 environment variable, or twice the number of available
196 processors (as shown by the 'getconf' utility), or 8.
197 Implies `--verbose -x --immediate` to get the most information
198 about the failure. Note that the verbose output of each test
199 job is saved to 't/test-results/$TEST_NAME.stress-<nr>.out',
200 and only the output of the failed test job is shown on the
201 terminal. The names of the trash directories get a
202 '.stress-<nr>' suffix, and the trash directory of the failed
203 test job is renamed to end with a '.stress-failed' suffix.
204
205 You can also set the GIT_TEST_INSTALLED environment variable to
206 the bindir of an existing git installation to test that installation.
207 You still need to have built this git sandbox, from which various
208 test-* support programs, templates, and perl libraries are used.
209 If your installed git is incomplete, it will silently test parts of
210 your built version instead.
211
212 When using GIT_TEST_INSTALLED, you can also set GIT_TEST_EXEC_PATH to
213 override the location of the dashed-form subcommands (what
214 GIT_EXEC_PATH would be used for during normal operation).
215 GIT_TEST_EXEC_PATH defaults to `$GIT_TEST_INSTALLED/git --exec-path`.
216
217
218 Skipping Tests
219 --------------
220
221 In some environments, certain tests have no way of succeeding
222 due to platform limitation, such as lack of 'unzip' program, or
223 filesystem that do not allow arbitrary sequence of non-NUL bytes
224 as pathnames.
225
226 You should be able to say something like
227
228 $ GIT_SKIP_TESTS=t9200.8 sh ./t9200-git-cvsexport-commit.sh
229
230 and even:
231
232 $ GIT_SKIP_TESTS='t[0-4]??? t91?? t9200.8' make
233
234 to omit such tests. The value of the environment variable is a
235 SP separated list of patterns that tells which tests to skip,
236 and either can match the "t[0-9]{4}" part to skip the whole
237 test, or t[0-9]{4} followed by ".$number" to say which
238 particular test to skip.
239
240 For an individual test suite --run could be used to specify that
241 only some tests should be run or that some tests should be
242 excluded from a run.
243
244 The argument for --run is a list of individual test numbers or
245 ranges with an optional negation prefix that define what tests in
246 a test suite to include in the run. A range is two numbers
247 separated with a dash and matches a range of tests with both ends
248 been included. You may omit the first or the second number to
249 mean "from the first test" or "up to the very last test"
250 respectively.
251
252 Optional prefix of '!' means that the test or a range of tests
253 should be excluded from the run.
254
255 If --run starts with an unprefixed number or range the initial
256 set of tests to run is empty. If the first item starts with '!'
257 all the tests are added to the initial set. After initial set is
258 determined every test number or range is added or excluded from
259 the set one by one, from left to right.
260
261 Individual numbers or ranges could be separated either by a space
262 or a comma.
263
264 For example, to run only tests up to a specific test (21), one
265 could do this:
266
267 $ sh ./t9200-git-cvsexport-commit.sh --run='1-21'
268
269 or this:
270
271 $ sh ./t9200-git-cvsexport-commit.sh --run='-21'
272
273 Common case is to run several setup tests (1, 2, 3) and then a
274 specific test (21) that relies on that setup:
275
276 $ sh ./t9200-git-cvsexport-commit.sh --run='1 2 3 21'
277
278 or:
279
280 $ sh ./t9200-git-cvsexport-commit.sh --run=1,2,3,21
281
282 or:
283
284 $ sh ./t9200-git-cvsexport-commit.sh --run='-3 21'
285
286 As noted above, the test set is built by going through the items
287 from left to right, so this:
288
289 $ sh ./t9200-git-cvsexport-commit.sh --run='1-4 !3'
290
291 will run tests 1, 2, and 4. Items that come later have higher
292 precedence. It means that this:
293
294 $ sh ./t9200-git-cvsexport-commit.sh --run='!3 1-4'
295
296 would just run tests from 1 to 4, including 3.
297
298 You may use negation with ranges. The following will run all
299 test in the test suite except from 7 up to 11:
300
301 $ sh ./t9200-git-cvsexport-commit.sh --run='!7-11'
302
303 Some tests in a test suite rely on the previous tests performing
304 certain actions, specifically some tests are designated as
305 "setup" test, so you cannot _arbitrarily_ disable one test and
306 expect the rest to function correctly.
307
308 --run is mostly useful when you want to focus on a specific test
309 and know what setup is needed for it. Or when you want to run
310 everything up to a certain test.
311
312
313 Running tests with special setups
314 ---------------------------------
315
316 The whole test suite could be run to test some special features
317 that cannot be easily covered by a few specific test cases. These
318 could be enabled by running the test suite with correct GIT_TEST_
319 environment set.
320
321 GIT_TEST_GETTEXT_POISON=<non-empty?> turns all strings marked for
322 translation into gibberish if non-empty (think "test -n"). Used for
323 spotting those tests that need to be marked with a C_LOCALE_OUTPUT
324 prerequisite when adding more strings for translation. See "Testing
325 marked strings" in po/README for details.
326
327 GIT_TEST_SPLIT_INDEX=<boolean> forces split-index mode on the whole
328 test suite. Accept any boolean values that are accepted by git-config.
329
330 GIT_TEST_FULL_IN_PACK_ARRAY=<boolean> exercises the uncommon
331 pack-objects code path where there are more than 1024 packs even if
332 the actual number of packs in repository is below this limit. Accept
333 any boolean values that are accepted by git-config.
334
335 GIT_TEST_OE_SIZE=<n> exercises the uncommon pack-objects code path
336 where we do not cache object size in memory and read it from existing
337 packs on demand. This normally only happens when the object size is
338 over 2GB. This variable forces the code path on any object larger than
339 <n> bytes.
340
341 GIT_TEST_OE_DELTA_SIZE=<n> exercises the uncommon pack-objects code
342 path where deltas larger than this limit require extra memory
343 allocation for bookkeeping.
344
345 GIT_TEST_VALIDATE_INDEX_CACHE_ENTRIES=<boolean> checks that cache-tree
346 records are valid when the index is written out or after a merge. This
347 is mostly to catch missing invalidation. Default is true.
348
349 GIT_TEST_COMMIT_GRAPH=<boolean>, when true, forces the commit-graph to
350 be written after every 'git commit' command, and overrides the
351 'core.commitGraph' setting to true.
352
353 GIT_TEST_FSMONITOR=$PWD/t7519/fsmonitor-all exercises the fsmonitor
354 code path for utilizing a file system monitor to speed up detecting
355 new or changed files.
356
357 GIT_TEST_INDEX_VERSION=<n> exercises the index read/write code path
358 for the index version specified. Can be set to any valid version
359 (currently 2, 3, or 4).
360
361 GIT_TEST_PRELOAD_INDEX=<boolean> exercises the preload-index code path
362 by overriding the minimum number of cache entries required per thread.
363
364 GIT_TEST_REBASE_USE_BUILTIN=<boolean>, when false, disables the
365 builtin version of git-rebase. See 'rebase.useBuiltin' in
366 git-config(1).
367
368 GIT_TEST_INDEX_THREADS=<n> enables exercising the multi-threaded loading
369 of the index for the whole test suite by bypassing the default number of
370 cache entries and thread minimums. Setting this to 1 will make the
371 index loading single threaded.
372
373 GIT_TEST_MULTI_PACK_INDEX=<boolean>, when true, forces the multi-pack-
374 index to be written after every 'git repack' command, and overrides the
375 'core.multiPackIndex' setting to true.
376
377 GIT_TEST_SIDEBAND_ALL=<boolean>, when true, overrides the
378 'uploadpack.allowSidebandAll' setting to true, and when false, forces
379 fetch-pack to not request sideband-all (even if the server advertises
380 sideband-all).
381
382 Naming Tests
383 ------------
384
385 The test files are named as:
386
387 tNNNN-commandname-details.sh
388
389 where N is a decimal digit.
390
391 First digit tells the family:
392
393 0 - the absolute basics and global stuff
394 1 - the basic commands concerning database
395 2 - the basic commands concerning the working tree
396 3 - the other basic commands (e.g. ls-files)
397 4 - the diff commands
398 5 - the pull and exporting commands
399 6 - the revision tree commands (even e.g. merge-base)
400 7 - the porcelainish commands concerning the working tree
401 8 - the porcelainish commands concerning forensics
402 9 - the git tools
403
404 Second digit tells the particular command we are testing.
405
406 Third digit (optionally) tells the particular switch or group of switches
407 we are testing.
408
409 If you create files under t/ directory (i.e. here) that is not
410 the top-level test script, never name the file to match the above
411 pattern. The Makefile here considers all such files as the
412 top-level test script and tries to run all of them. Care is
413 especially needed if you are creating a common test library
414 file, similar to test-lib.sh, because such a library file may
415 not be suitable for standalone execution.
416
417
418 Writing Tests
419 -------------
420
421 The test script is written as a shell script. It should start
422 with the standard "#!/bin/sh", and an
423 assignment to variable 'test_description', like this:
424
425 #!/bin/sh
426
427 test_description='xxx test (option --frotz)
428
429 This test registers the following structure in the cache
430 and tries to run git-ls-files with option --frotz.'
431
432
433 Source 'test-lib.sh'
434 --------------------
435
436 After assigning test_description, the test script should source
437 test-lib.sh like this:
438
439 . ./test-lib.sh
440
441 This test harness library does the following things:
442
443 - If the script is invoked with command line argument --help
444 (or -h), it shows the test_description and exits.
445
446 - Creates an empty test directory with an empty .git/objects database
447 and chdir(2) into it. This directory is 't/trash
448 directory.$test_name_without_dotsh', with t/ subject to change by
449 the --root option documented above, and a '.stress-<N>' suffix
450 appended by the --stress option.
451
452 - Defines standard test helper functions for your scripts to
453 use. These functions are designed to make all scripts behave
454 consistently when command line arguments --verbose (or -v),
455 --debug (or -d), and --immediate (or -i) is given.
456
457 Do's & don'ts
458 -------------
459
460 Here are a few examples of things you probably should and shouldn't do
461 when writing tests.
462
463 Here are the "do's:"
464
465 - Put all code inside test_expect_success and other assertions.
466
467 Even code that isn't a test per se, but merely some setup code
468 should be inside a test assertion.
469
470 - Chain your test assertions
471
472 Write test code like this:
473
474 git merge foo &&
475 git push bar &&
476 test ...
477
478 Instead of:
479
480 git merge hla
481 git push gh
482 test ...
483
484 That way all of the commands in your tests will succeed or fail. If
485 you must ignore the return value of something, consider using a
486 helper function (e.g. use sane_unset instead of unset, in order
487 to avoid unportable return value for unsetting a variable that was
488 already unset), or prepending the command with test_might_fail or
489 test_must_fail.
490
491 - Check the test coverage for your tests. See the "Test coverage"
492 below.
493
494 Don't blindly follow test coverage metrics; if a new function you added
495 doesn't have any coverage, then you're probably doing something wrong,
496 but having 100% coverage doesn't necessarily mean that you tested
497 everything.
498
499 Tests that are likely to smoke out future regressions are better
500 than tests that just inflate the coverage metrics.
501
502 - When a test checks for an absolute path that a git command generated,
503 construct the expected value using $(pwd) rather than $PWD,
504 $TEST_DIRECTORY, or $TRASH_DIRECTORY. It makes a difference on
505 Windows, where the shell (MSYS bash) mangles absolute path names.
506 For details, see the commit message of 4114156ae9.
507
508 - Remember that inside the <script> part, the standard output and
509 standard error streams are discarded, and the test harness only
510 reports "ok" or "not ok" to the end user running the tests. Under
511 --verbose, they are shown to help debug the tests.
512
513 And here are the "don'ts:"
514
515 - Don't exit() within a <script> part.
516
517 The harness will catch this as a programming error of the test.
518 Use test_done instead if you need to stop the tests early (see
519 "Skipping tests" below).
520
521 - Don't use '! git cmd' when you want to make sure the git command
522 exits with failure in a controlled way by calling "die()". Instead,
523 use 'test_must_fail git cmd'. This will signal a failure if git
524 dies in an unexpected way (e.g. segfault).
525
526 On the other hand, don't use test_must_fail for running regular
527 platform commands; just use '! cmd'. We are not in the business
528 of verifying that the world given to us sanely works.
529
530 - Don't feed the output of a git command to a pipe, as in:
531
532 git -C repo ls-files |
533 xargs -n 1 basename |
534 grep foo
535
536 which will discard git's exit code and may mask a crash. In the
537 above example, all exit codes are ignored except grep's.
538
539 Instead, write the output of that command to a temporary
540 file with ">" or assign it to a variable with "x=$(git ...)" rather
541 than pipe it.
542
543 - Don't use command substitution in a way that discards git's exit
544 code. When assigning to a variable, the exit code is not discarded,
545 e.g.:
546
547 x=$(git cat-file -p $sha) &&
548 ...
549
550 is OK because a crash in "git cat-file" will cause the "&&" chain
551 to fail, but:
552
553 test "refs/heads/foo" = "$(git symbolic-ref HEAD)"
554
555 is not OK and a crash in git could go undetected.
556
557 - Don't use perl without spelling it as "$PERL_PATH". This is to help
558 our friends on Windows where the platform Perl often adds CR before
559 the end of line, and they bundle Git with a version of Perl that
560 does not do so, whose path is specified with $PERL_PATH. Note that we
561 provide a "perl" function which uses $PERL_PATH under the hood, so
562 you do not need to worry when simply running perl in the test scripts
563 (but you do, for example, on a shebang line or in a sub script
564 created via "write_script").
565
566 - Don't use sh without spelling it as "$SHELL_PATH", when the script
567 can be misinterpreted by broken platform shell (e.g. Solaris).
568
569 - Don't chdir around in tests. It is not sufficient to chdir to
570 somewhere and then chdir back to the original location later in
571 the test, as any intermediate step can fail and abort the test,
572 causing the next test to start in an unexpected directory. Do so
573 inside a subshell if necessary.
574
575 - Don't save and verify the standard error of compound commands, i.e.
576 group commands, subshells, and shell functions (except test helper
577 functions like 'test_must_fail') like this:
578
579 ( cd dir && git cmd ) 2>error &&
580 test_cmp expect error
581
582 When running the test with '-x' tracing, then the trace of commands
583 executed in the compound command will be included in standard error
584 as well, quite possibly throwing off the subsequent checks examining
585 the output. Instead, save only the relevant git command's standard
586 error:
587
588 ( cd dir && git cmd 2>../error ) &&
589 test_cmp expect error
590
591 - Don't break the TAP output
592
593 The raw output from your test may be interpreted by a TAP harness. TAP
594 harnesses will ignore everything they don't know about, but don't step
595 on their toes in these areas:
596
597 - Don't print lines like "$x..$y" where $x and $y are integers.
598
599 - Don't print lines that begin with "ok" or "not ok".
600
601 TAP harnesses expect a line that begins with either "ok" and "not
602 ok" to signal a test passed or failed (and our harness already
603 produces such lines), so your script shouldn't emit such lines to
604 their output.
605
606 You can glean some further possible issues from the TAP grammar
607 (see https://metacpan.org/pod/TAP::Parser::Grammar#TAP-GRAMMAR)
608 but the best indication is to just run the tests with prove(1),
609 it'll complain if anything is amiss.
610
611
612 Skipping tests
613 --------------
614
615 If you need to skip tests you should do so by using the three-arg form
616 of the test_* functions (see the "Test harness library" section
617 below), e.g.:
618
619 test_expect_success PERL 'I need Perl' '
620 perl -e "hlagh() if unf_unf()"
621 '
622
623 The advantage of skipping tests like this is that platforms that don't
624 have the PERL and other optional dependencies get an indication of how
625 many tests they're missing.
626
627 If the test code is too hairy for that (i.e. does a lot of setup work
628 outside test assertions) you can also skip all remaining tests by
629 setting skip_all and immediately call test_done:
630
631 if ! test_have_prereq PERL
632 then
633 skip_all='skipping perl interface tests, perl not available'
634 test_done
635 fi
636
637 The string you give to skip_all will be used as an explanation for why
638 the test was skipped.
639
640 End with test_done
641 ------------------
642
643 Your script will be a sequence of tests, using helper functions
644 from the test harness library. At the end of the script, call
645 'test_done'.
646
647
648 Test harness library
649 --------------------
650
651 There are a handful helper functions defined in the test harness
652 library for your script to use.
653
654 - test_expect_success [<prereq>] <message> <script>
655
656 Usually takes two strings as parameters, and evaluates the
657 <script>. If it yields success, test is considered
658 successful. <message> should state what it is testing.
659
660 Example:
661
662 test_expect_success \
663 'git-write-tree should be able to write an empty tree.' \
664 'tree=$(git-write-tree)'
665
666 If you supply three parameters the first will be taken to be a
667 prerequisite; see the test_set_prereq and test_have_prereq
668 documentation below:
669
670 test_expect_success TTY 'git --paginate rev-list uses a pager' \
671 ' ... '
672
673 You can also supply a comma-separated list of prerequisites, in the
674 rare case where your test depends on more than one:
675
676 test_expect_success PERL,PYTHON 'yo dawg' \
677 ' test $(perl -E 'print eval "1 +" . qx[python -c "print 2"]') == "4" '
678
679 - test_expect_failure [<prereq>] <message> <script>
680
681 This is NOT the opposite of test_expect_success, but is used
682 to mark a test that demonstrates a known breakage. Unlike
683 the usual test_expect_success tests, which say "ok" on
684 success and "FAIL" on failure, this will say "FIXED" on
685 success and "still broken" on failure. Failures from these
686 tests won't cause -i (immediate) to stop.
687
688 Like test_expect_success this function can optionally use a three
689 argument invocation with a prerequisite as the first argument.
690
691 - test_debug <script>
692
693 This takes a single argument, <script>, and evaluates it only
694 when the test script is started with --debug command line
695 argument. This is primarily meant for use during the
696 development of a new test script.
697
698 - debug <git-command>
699
700 Run a git command inside a debugger. This is primarily meant for
701 use when debugging a failing test script.
702
703 - test_done
704
705 Your test script must have test_done at the end. Its purpose
706 is to summarize successes and failures in the test script and
707 exit with an appropriate error code.
708
709 - test_tick
710
711 Make commit and tag names consistent by setting the author and
712 committer times to defined state. Subsequent calls will
713 advance the times by a fixed amount.
714
715 - test_commit <message> [<filename> [<contents>]]
716
717 Creates a commit with the given message, committing the given
718 file with the given contents (default for both is to reuse the
719 message string), and adds a tag (again reusing the message
720 string as name). Calls test_tick to make the SHA-1s
721 reproducible.
722
723 - test_merge <message> <commit-or-tag>
724
725 Merges the given rev using the given message. Like test_commit,
726 creates a tag and calls test_tick before committing.
727
728 - test_set_prereq <prereq>
729
730 Set a test prerequisite to be used later with test_have_prereq. The
731 test-lib will set some prerequisites for you, see the
732 "Prerequisites" section below for a full list of these.
733
734 Others you can set yourself and use later with either
735 test_have_prereq directly, or the three argument invocation of
736 test_expect_success and test_expect_failure.
737
738 - test_have_prereq <prereq>
739
740 Check if we have a prerequisite previously set with test_set_prereq.
741 The most common way to use this explicitly (as opposed to the
742 implicit use when an argument is passed to test_expect_*) is to skip
743 all the tests at the start of the test script if we don't have some
744 essential prerequisite:
745
746 if ! test_have_prereq PERL
747 then
748 skip_all='skipping perl interface tests, perl not available'
749 test_done
750 fi
751
752 - test_external [<prereq>] <message> <external> <script>
753
754 Execute a <script> with an <external> interpreter (like perl). This
755 was added for tests like t9700-perl-git.sh which do most of their
756 work in an external test script.
757
758 test_external \
759 'GitwebCache::*FileCache*' \
760 perl "$TEST_DIRECTORY"/t9503/test_cache_interface.pl
761
762 If the test is outputting its own TAP you should set the
763 test_external_has_tap variable somewhere before calling the first
764 test_external* function. See t9700-perl-git.sh for an example.
765
766 # The external test will outputs its own plan
767 test_external_has_tap=1
768
769 - test_external_without_stderr [<prereq>] <message> <external> <script>
770
771 Like test_external but fail if there's any output on stderr,
772 instead of checking the exit code.
773
774 test_external_without_stderr \
775 'Perl API' \
776 perl "$TEST_DIRECTORY"/t9700/test.pl
777
778 - test_expect_code <exit-code> <command>
779
780 Run a command and ensure that it exits with the given exit code.
781 For example:
782
783 test_expect_success 'Merge with d/f conflicts' '
784 test_expect_code 1 git merge "merge msg" B master
785 '
786
787 - test_must_fail [<options>] <git-command>
788
789 Run a git command and ensure it fails in a controlled way. Use
790 this instead of "! <git-command>". When git-command dies due to a
791 segfault, test_must_fail diagnoses it as an error; "! <git-command>"
792 treats it as just another expected failure, which would let such a
793 bug go unnoticed.
794
795 Accepts the following options:
796
797 ok=<signal-name>[,<...>]:
798 Don't treat an exit caused by the given signal as error.
799 Multiple signals can be specified as a comma separated list.
800 Currently recognized signal names are: sigpipe, success.
801 (Don't use 'success', use 'test_might_fail' instead.)
802
803 - test_might_fail [<options>] <git-command>
804
805 Similar to test_must_fail, but tolerate success, too. Use this
806 instead of "<git-command> || :" to catch failures due to segv.
807
808 Accepts the same options as test_must_fail.
809
810 - test_cmp <expected> <actual>
811
812 Check whether the content of the <actual> file matches the
813 <expected> file. This behaves like "cmp" but produces more
814 helpful output when the test is run with "-v" option.
815
816 - test_cmp_rev <expected> <actual>
817
818 Check whether the <expected> rev points to the same commit as the
819 <actual> rev.
820
821 - test_line_count (= | -lt | -ge | ...) <length> <file>
822
823 Check whether a file has the length it is expected to.
824
825 - test_path_is_file <path> [<diagnosis>]
826 test_path_is_dir <path> [<diagnosis>]
827 test_path_is_missing <path> [<diagnosis>]
828
829 Check if the named path is a file, if the named path is a
830 directory, or if the named path does not exist, respectively,
831 and fail otherwise, showing the <diagnosis> text.
832
833 - test_when_finished <script>
834
835 Prepend <script> to a list of commands to run to clean up
836 at the end of the current test. If some clean-up command
837 fails, the test will not pass.
838
839 Example:
840
841 test_expect_success 'branch pointing to non-commit' '
842 git rev-parse HEAD^{tree} >.git/refs/heads/invalid &&
843 test_when_finished "git update-ref -d refs/heads/invalid" &&
844 ...
845 '
846
847 - test_write_lines <lines>
848
849 Write <lines> on standard output, one line per argument.
850 Useful to prepare multi-line files in a compact form.
851
852 Example:
853
854 test_write_lines a b c d e f g >foo
855
856 Is a more compact equivalent of:
857 cat >foo <<-EOF
858 a
859 b
860 c
861 d
862 e
863 f
864 g
865 EOF
866
867
868 - test_pause
869
870 This command is useful for writing and debugging tests and must be
871 removed before submitting. It halts the execution of the test and
872 spawns a shell in the trash directory. Exit the shell to continue
873 the test. Example:
874
875 test_expect_success 'test' '
876 git do-something >actual &&
877 test_pause &&
878 test_cmp expected actual
879 '
880
881 - test_ln_s_add <path1> <path2>
882
883 This function helps systems whose filesystem does not support symbolic
884 links. Use it to add a symbolic link entry to the index when it is not
885 important that the file system entry is a symbolic link, i.e., instead
886 of the sequence
887
888 ln -s foo bar &&
889 git add bar
890
891 Sometimes it is possible to split a test in a part that does not need
892 the symbolic link in the file system and a part that does; then only
893 the latter part need be protected by a SYMLINKS prerequisite (see below).
894
895 - test_oid_init
896
897 This function loads facts and useful object IDs related to the hash
898 algorithm(s) in use from the files in t/oid-info.
899
900 - test_oid_cache
901
902 This function reads per-hash algorithm information from standard
903 input (usually a heredoc) in the format described in
904 t/oid-info/README. This is useful for test-specific values, such as
905 object IDs, which must vary based on the hash algorithm.
906
907 Certain fixed values, such as hash sizes and common placeholder
908 object IDs, can be loaded with test_oid_init (described above).
909
910 - test_oid <key>
911
912 This function looks up a value for the hash algorithm in use, based
913 on the key given. The value must have been loaded using
914 test_oid_init or test_oid_cache. Providing an unknown key is an
915 error.
916
917 Prerequisites
918 -------------
919
920 These are the prerequisites that the test library predefines with
921 test_have_prereq.
922
923 See the prereq argument to the test_* functions in the "Test harness
924 library" section above and the "test_have_prereq" function for how to
925 use these, and "test_set_prereq" for how to define your own.
926
927 - PYTHON
928
929 Git wasn't compiled with NO_PYTHON=YesPlease. Wrap any tests that
930 need Python with this.
931
932 - PERL
933
934 Git wasn't compiled with NO_PERL=YesPlease.
935
936 Even without the PERL prerequisite, tests can assume there is a
937 usable perl interpreter at $PERL_PATH, though it need not be
938 particularly modern.
939
940 - POSIXPERM
941
942 The filesystem supports POSIX style permission bits.
943
944 - BSLASHPSPEC
945
946 Backslashes in pathspec are not directory separators. This is not
947 set on Windows. See 6fd1106a for details.
948
949 - EXECKEEPSPID
950
951 The process retains the same pid across exec(2). See fb9a2bea for
952 details.
953
954 - PIPE
955
956 The filesystem we're on supports creation of FIFOs (named pipes)
957 via mkfifo(1).
958
959 - SYMLINKS
960
961 The filesystem we're on supports symbolic links. E.g. a FAT
962 filesystem doesn't support these. See 704a3143 for details.
963
964 - SANITY
965
966 Test is not run by root user, and an attempt to write to an
967 unwritable file is expected to fail correctly.
968
969 - PCRE
970
971 Git was compiled with support for PCRE. Wrap any tests
972 that use git-grep --perl-regexp or git-grep -P in these.
973
974 - LIBPCRE1
975
976 Git was compiled with PCRE v1 support via
977 USE_LIBPCRE1=YesPlease. Wrap any PCRE using tests that for some
978 reason need v1 of the PCRE library instead of v2 in these.
979
980 - LIBPCRE2
981
982 Git was compiled with PCRE v2 support via
983 USE_LIBPCRE2=YesPlease. Wrap any PCRE using tests that for some
984 reason need v2 of the PCRE library instead of v1 in these.
985
986 - CASE_INSENSITIVE_FS
987
988 Test is run on a case insensitive file system.
989
990 - UTF8_NFD_TO_NFC
991
992 Test is run on a filesystem which converts decomposed utf-8 (nfd)
993 to precomposed utf-8 (nfc).
994
995 - PTHREADS
996
997 Git wasn't compiled with NO_PTHREADS=YesPlease.
998
999 Tips for Writing Tests
1000 ----------------------
1001
1002 As with any programming projects, existing programs are the best
1003 source of the information. However, do _not_ emulate
1004 t0000-basic.sh when writing your tests. The test is special in
1005 that it tries to validate the very core of GIT. For example, it
1006 knows that there will be 256 subdirectories under .git/objects/,
1007 and it knows that the object ID of an empty tree is a certain
1008 40-byte string. This is deliberately done so in t0000-basic.sh
1009 because the things the very basic core test tries to achieve is
1010 to serve as a basis for people who are changing the GIT internal
1011 drastically. For these people, after making certain changes,
1012 not seeing failures from the basic test _is_ a failure. And
1013 such drastic changes to the core GIT that even changes these
1014 otherwise supposedly stable object IDs should be accompanied by
1015 an update to t0000-basic.sh.
1016
1017 However, other tests that simply rely on basic parts of the core
1018 GIT working properly should not have that level of intimate
1019 knowledge of the core GIT internals. If all the test scripts
1020 hardcoded the object IDs like t0000-basic.sh does, that defeats
1021 the purpose of t0000-basic.sh, which is to isolate that level of
1022 validation in one place. Your test also ends up needing
1023 updating when such a change to the internal happens, so do _not_
1024 do it and leave the low level of validation to t0000-basic.sh.
1025
1026 Test coverage
1027 -------------
1028
1029 You can use the coverage tests to find code paths that are not being
1030 used or properly exercised yet.
1031
1032 To do that, run the coverage target at the top-level (not in the t/
1033 directory):
1034
1035 make coverage
1036
1037 That'll compile Git with GCC's coverage arguments, and generate a test
1038 report with gcov after the tests finish. Running the coverage tests
1039 can take a while, since running the tests in parallel is incompatible
1040 with GCC's coverage mode.
1041
1042 After the tests have run you can generate a list of untested
1043 functions:
1044
1045 make coverage-untested-functions
1046
1047 You can also generate a detailed per-file HTML report using the
1048 Devel::Cover module. To install it do:
1049
1050 # On Debian or Ubuntu:
1051 sudo aptitude install libdevel-cover-perl
1052
1053 # From the CPAN with cpanminus
1054 curl -L http://cpanmin.us | perl - --sudo --self-upgrade
1055 cpanm --sudo Devel::Cover
1056
1057 Then, at the top-level:
1058
1059 make cover_db_html
1060
1061 That'll generate a detailed cover report in the "cover_db_html"
1062 directory, which you can then copy to a webserver, or inspect locally
1063 in a browser.