Merge branch 'sg/stress-test'
[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 Naming Tests
378 ------------
379
380 The test files are named as:
381
382 tNNNN-commandname-details.sh
383
384 where N is a decimal digit.
385
386 First digit tells the family:
387
388 0 - the absolute basics and global stuff
389 1 - the basic commands concerning database
390 2 - the basic commands concerning the working tree
391 3 - the other basic commands (e.g. ls-files)
392 4 - the diff commands
393 5 - the pull and exporting commands
394 6 - the revision tree commands (even e.g. merge-base)
395 7 - the porcelainish commands concerning the working tree
396 8 - the porcelainish commands concerning forensics
397 9 - the git tools
398
399 Second digit tells the particular command we are testing.
400
401 Third digit (optionally) tells the particular switch or group of switches
402 we are testing.
403
404 If you create files under t/ directory (i.e. here) that is not
405 the top-level test script, never name the file to match the above
406 pattern. The Makefile here considers all such files as the
407 top-level test script and tries to run all of them. Care is
408 especially needed if you are creating a common test library
409 file, similar to test-lib.sh, because such a library file may
410 not be suitable for standalone execution.
411
412
413 Writing Tests
414 -------------
415
416 The test script is written as a shell script. It should start
417 with the standard "#!/bin/sh", and an
418 assignment to variable 'test_description', like this:
419
420 #!/bin/sh
421
422 test_description='xxx test (option --frotz)
423
424 This test registers the following structure in the cache
425 and tries to run git-ls-files with option --frotz.'
426
427
428 Source 'test-lib.sh'
429 --------------------
430
431 After assigning test_description, the test script should source
432 test-lib.sh like this:
433
434 . ./test-lib.sh
435
436 This test harness library does the following things:
437
438 - If the script is invoked with command line argument --help
439 (or -h), it shows the test_description and exits.
440
441 - Creates an empty test directory with an empty .git/objects database
442 and chdir(2) into it. This directory is 't/trash
443 directory.$test_name_without_dotsh', with t/ subject to change by
444 the --root option documented above, and a '.stress-<N>' suffix
445 appended by the --stress option.
446
447 - Defines standard test helper functions for your scripts to
448 use. These functions are designed to make all scripts behave
449 consistently when command line arguments --verbose (or -v),
450 --debug (or -d), and --immediate (or -i) is given.
451
452 Do's & don'ts
453 -------------
454
455 Here are a few examples of things you probably should and shouldn't do
456 when writing tests.
457
458 Here are the "do's:"
459
460 - Put all code inside test_expect_success and other assertions.
461
462 Even code that isn't a test per se, but merely some setup code
463 should be inside a test assertion.
464
465 - Chain your test assertions
466
467 Write test code like this:
468
469 git merge foo &&
470 git push bar &&
471 test ...
472
473 Instead of:
474
475 git merge hla
476 git push gh
477 test ...
478
479 That way all of the commands in your tests will succeed or fail. If
480 you must ignore the return value of something, consider using a
481 helper function (e.g. use sane_unset instead of unset, in order
482 to avoid unportable return value for unsetting a variable that was
483 already unset), or prepending the command with test_might_fail or
484 test_must_fail.
485
486 - Check the test coverage for your tests. See the "Test coverage"
487 below.
488
489 Don't blindly follow test coverage metrics; if a new function you added
490 doesn't have any coverage, then you're probably doing something wrong,
491 but having 100% coverage doesn't necessarily mean that you tested
492 everything.
493
494 Tests that are likely to smoke out future regressions are better
495 than tests that just inflate the coverage metrics.
496
497 - When a test checks for an absolute path that a git command generated,
498 construct the expected value using $(pwd) rather than $PWD,
499 $TEST_DIRECTORY, or $TRASH_DIRECTORY. It makes a difference on
500 Windows, where the shell (MSYS bash) mangles absolute path names.
501 For details, see the commit message of 4114156ae9.
502
503 - Remember that inside the <script> part, the standard output and
504 standard error streams are discarded, and the test harness only
505 reports "ok" or "not ok" to the end user running the tests. Under
506 --verbose, they are shown to help debug the tests.
507
508 And here are the "don'ts:"
509
510 - Don't exit() within a <script> part.
511
512 The harness will catch this as a programming error of the test.
513 Use test_done instead if you need to stop the tests early (see
514 "Skipping tests" below).
515
516 - Don't use '! git cmd' when you want to make sure the git command
517 exits with failure in a controlled way by calling "die()". Instead,
518 use 'test_must_fail git cmd'. This will signal a failure if git
519 dies in an unexpected way (e.g. segfault).
520
521 On the other hand, don't use test_must_fail for running regular
522 platform commands; just use '! cmd'. We are not in the business
523 of verifying that the world given to us sanely works.
524
525 - Don't feed the output of a git command to a pipe, as in:
526
527 git -C repo ls-files |
528 xargs -n 1 basename |
529 grep foo
530
531 which will discard git's exit code and may mask a crash. In the
532 above example, all exit codes are ignored except grep's.
533
534 Instead, write the output of that command to a temporary
535 file with ">" or assign it to a variable with "x=$(git ...)" rather
536 than pipe it.
537
538 - Don't use command substitution in a way that discards git's exit
539 code. When assigning to a variable, the exit code is not discarded,
540 e.g.:
541
542 x=$(git cat-file -p $sha) &&
543 ...
544
545 is OK because a crash in "git cat-file" will cause the "&&" chain
546 to fail, but:
547
548 test "refs/heads/foo" = "$(git symbolic-ref HEAD)"
549
550 is not OK and a crash in git could go undetected.
551
552 - Don't use perl without spelling it as "$PERL_PATH". This is to help
553 our friends on Windows where the platform Perl often adds CR before
554 the end of line, and they bundle Git with a version of Perl that
555 does not do so, whose path is specified with $PERL_PATH. Note that we
556 provide a "perl" function which uses $PERL_PATH under the hood, so
557 you do not need to worry when simply running perl in the test scripts
558 (but you do, for example, on a shebang line or in a sub script
559 created via "write_script").
560
561 - Don't use sh without spelling it as "$SHELL_PATH", when the script
562 can be misinterpreted by broken platform shell (e.g. Solaris).
563
564 - Don't chdir around in tests. It is not sufficient to chdir to
565 somewhere and then chdir back to the original location later in
566 the test, as any intermediate step can fail and abort the test,
567 causing the next test to start in an unexpected directory. Do so
568 inside a subshell if necessary.
569
570 - Don't save and verify the standard error of compound commands, i.e.
571 group commands, subshells, and shell functions (except test helper
572 functions like 'test_must_fail') like this:
573
574 ( cd dir && git cmd ) 2>error &&
575 test_cmp expect error
576
577 When running the test with '-x' tracing, then the trace of commands
578 executed in the compound command will be included in standard error
579 as well, quite possibly throwing off the subsequent checks examining
580 the output. Instead, save only the relevant git command's standard
581 error:
582
583 ( cd dir && git cmd 2>../error ) &&
584 test_cmp expect error
585
586 - Don't break the TAP output
587
588 The raw output from your test may be interpreted by a TAP harness. TAP
589 harnesses will ignore everything they don't know about, but don't step
590 on their toes in these areas:
591
592 - Don't print lines like "$x..$y" where $x and $y are integers.
593
594 - Don't print lines that begin with "ok" or "not ok".
595
596 TAP harnesses expect a line that begins with either "ok" and "not
597 ok" to signal a test passed or failed (and our harness already
598 produces such lines), so your script shouldn't emit such lines to
599 their output.
600
601 You can glean some further possible issues from the TAP grammar
602 (see https://metacpan.org/pod/TAP::Parser::Grammar#TAP-GRAMMAR)
603 but the best indication is to just run the tests with prove(1),
604 it'll complain if anything is amiss.
605
606
607 Skipping tests
608 --------------
609
610 If you need to skip tests you should do so by using the three-arg form
611 of the test_* functions (see the "Test harness library" section
612 below), e.g.:
613
614 test_expect_success PERL 'I need Perl' '
615 perl -e "hlagh() if unf_unf()"
616 '
617
618 The advantage of skipping tests like this is that platforms that don't
619 have the PERL and other optional dependencies get an indication of how
620 many tests they're missing.
621
622 If the test code is too hairy for that (i.e. does a lot of setup work
623 outside test assertions) you can also skip all remaining tests by
624 setting skip_all and immediately call test_done:
625
626 if ! test_have_prereq PERL
627 then
628 skip_all='skipping perl interface tests, perl not available'
629 test_done
630 fi
631
632 The string you give to skip_all will be used as an explanation for why
633 the test was skipped.
634
635 End with test_done
636 ------------------
637
638 Your script will be a sequence of tests, using helper functions
639 from the test harness library. At the end of the script, call
640 'test_done'.
641
642
643 Test harness library
644 --------------------
645
646 There are a handful helper functions defined in the test harness
647 library for your script to use.
648
649 - test_expect_success [<prereq>] <message> <script>
650
651 Usually takes two strings as parameters, and evaluates the
652 <script>. If it yields success, test is considered
653 successful. <message> should state what it is testing.
654
655 Example:
656
657 test_expect_success \
658 'git-write-tree should be able to write an empty tree.' \
659 'tree=$(git-write-tree)'
660
661 If you supply three parameters the first will be taken to be a
662 prerequisite; see the test_set_prereq and test_have_prereq
663 documentation below:
664
665 test_expect_success TTY 'git --paginate rev-list uses a pager' \
666 ' ... '
667
668 You can also supply a comma-separated list of prerequisites, in the
669 rare case where your test depends on more than one:
670
671 test_expect_success PERL,PYTHON 'yo dawg' \
672 ' test $(perl -E 'print eval "1 +" . qx[python -c "print 2"]') == "4" '
673
674 - test_expect_failure [<prereq>] <message> <script>
675
676 This is NOT the opposite of test_expect_success, but is used
677 to mark a test that demonstrates a known breakage. Unlike
678 the usual test_expect_success tests, which say "ok" on
679 success and "FAIL" on failure, this will say "FIXED" on
680 success and "still broken" on failure. Failures from these
681 tests won't cause -i (immediate) to stop.
682
683 Like test_expect_success this function can optionally use a three
684 argument invocation with a prerequisite as the first argument.
685
686 - test_debug <script>
687
688 This takes a single argument, <script>, and evaluates it only
689 when the test script is started with --debug command line
690 argument. This is primarily meant for use during the
691 development of a new test script.
692
693 - debug <git-command>
694
695 Run a git command inside a debugger. This is primarily meant for
696 use when debugging a failing test script.
697
698 - test_done
699
700 Your test script must have test_done at the end. Its purpose
701 is to summarize successes and failures in the test script and
702 exit with an appropriate error code.
703
704 - test_tick
705
706 Make commit and tag names consistent by setting the author and
707 committer times to defined state. Subsequent calls will
708 advance the times by a fixed amount.
709
710 - test_commit <message> [<filename> [<contents>]]
711
712 Creates a commit with the given message, committing the given
713 file with the given contents (default for both is to reuse the
714 message string), and adds a tag (again reusing the message
715 string as name). Calls test_tick to make the SHA-1s
716 reproducible.
717
718 - test_merge <message> <commit-or-tag>
719
720 Merges the given rev using the given message. Like test_commit,
721 creates a tag and calls test_tick before committing.
722
723 - test_set_prereq <prereq>
724
725 Set a test prerequisite to be used later with test_have_prereq. The
726 test-lib will set some prerequisites for you, see the
727 "Prerequisites" section below for a full list of these.
728
729 Others you can set yourself and use later with either
730 test_have_prereq directly, or the three argument invocation of
731 test_expect_success and test_expect_failure.
732
733 - test_have_prereq <prereq>
734
735 Check if we have a prerequisite previously set with test_set_prereq.
736 The most common way to use this explicitly (as opposed to the
737 implicit use when an argument is passed to test_expect_*) is to skip
738 all the tests at the start of the test script if we don't have some
739 essential prerequisite:
740
741 if ! test_have_prereq PERL
742 then
743 skip_all='skipping perl interface tests, perl not available'
744 test_done
745 fi
746
747 - test_external [<prereq>] <message> <external> <script>
748
749 Execute a <script> with an <external> interpreter (like perl). This
750 was added for tests like t9700-perl-git.sh which do most of their
751 work in an external test script.
752
753 test_external \
754 'GitwebCache::*FileCache*' \
755 perl "$TEST_DIRECTORY"/t9503/test_cache_interface.pl
756
757 If the test is outputting its own TAP you should set the
758 test_external_has_tap variable somewhere before calling the first
759 test_external* function. See t9700-perl-git.sh for an example.
760
761 # The external test will outputs its own plan
762 test_external_has_tap=1
763
764 - test_external_without_stderr [<prereq>] <message> <external> <script>
765
766 Like test_external but fail if there's any output on stderr,
767 instead of checking the exit code.
768
769 test_external_without_stderr \
770 'Perl API' \
771 perl "$TEST_DIRECTORY"/t9700/test.pl
772
773 - test_expect_code <exit-code> <command>
774
775 Run a command and ensure that it exits with the given exit code.
776 For example:
777
778 test_expect_success 'Merge with d/f conflicts' '
779 test_expect_code 1 git merge "merge msg" B master
780 '
781
782 - test_must_fail [<options>] <git-command>
783
784 Run a git command and ensure it fails in a controlled way. Use
785 this instead of "! <git-command>". When git-command dies due to a
786 segfault, test_must_fail diagnoses it as an error; "! <git-command>"
787 treats it as just another expected failure, which would let such a
788 bug go unnoticed.
789
790 Accepts the following options:
791
792 ok=<signal-name>[,<...>]:
793 Don't treat an exit caused by the given signal as error.
794 Multiple signals can be specified as a comma separated list.
795 Currently recognized signal names are: sigpipe, success.
796 (Don't use 'success', use 'test_might_fail' instead.)
797
798 - test_might_fail [<options>] <git-command>
799
800 Similar to test_must_fail, but tolerate success, too. Use this
801 instead of "<git-command> || :" to catch failures due to segv.
802
803 Accepts the same options as test_must_fail.
804
805 - test_cmp <expected> <actual>
806
807 Check whether the content of the <actual> file matches the
808 <expected> file. This behaves like "cmp" but produces more
809 helpful output when the test is run with "-v" option.
810
811 - test_cmp_rev <expected> <actual>
812
813 Check whether the <expected> rev points to the same commit as the
814 <actual> rev.
815
816 - test_line_count (= | -lt | -ge | ...) <length> <file>
817
818 Check whether a file has the length it is expected to.
819
820 - test_path_is_file <path> [<diagnosis>]
821 test_path_is_dir <path> [<diagnosis>]
822 test_path_is_missing <path> [<diagnosis>]
823
824 Check if the named path is a file, if the named path is a
825 directory, or if the named path does not exist, respectively,
826 and fail otherwise, showing the <diagnosis> text.
827
828 - test_when_finished <script>
829
830 Prepend <script> to a list of commands to run to clean up
831 at the end of the current test. If some clean-up command
832 fails, the test will not pass.
833
834 Example:
835
836 test_expect_success 'branch pointing to non-commit' '
837 git rev-parse HEAD^{tree} >.git/refs/heads/invalid &&
838 test_when_finished "git update-ref -d refs/heads/invalid" &&
839 ...
840 '
841
842 - test_write_lines <lines>
843
844 Write <lines> on standard output, one line per argument.
845 Useful to prepare multi-line files in a compact form.
846
847 Example:
848
849 test_write_lines a b c d e f g >foo
850
851 Is a more compact equivalent of:
852 cat >foo <<-EOF
853 a
854 b
855 c
856 d
857 e
858 f
859 g
860 EOF
861
862
863 - test_pause
864
865 This command is useful for writing and debugging tests and must be
866 removed before submitting. It halts the execution of the test and
867 spawns a shell in the trash directory. Exit the shell to continue
868 the test. Example:
869
870 test_expect_success 'test' '
871 git do-something >actual &&
872 test_pause &&
873 test_cmp expected actual
874 '
875
876 - test_ln_s_add <path1> <path2>
877
878 This function helps systems whose filesystem does not support symbolic
879 links. Use it to add a symbolic link entry to the index when it is not
880 important that the file system entry is a symbolic link, i.e., instead
881 of the sequence
882
883 ln -s foo bar &&
884 git add bar
885
886 Sometimes it is possible to split a test in a part that does not need
887 the symbolic link in the file system and a part that does; then only
888 the latter part need be protected by a SYMLINKS prerequisite (see below).
889
890 - test_oid_init
891
892 This function loads facts and useful object IDs related to the hash
893 algorithm(s) in use from the files in t/oid-info.
894
895 - test_oid_cache
896
897 This function reads per-hash algorithm information from standard
898 input (usually a heredoc) in the format described in
899 t/oid-info/README. This is useful for test-specific values, such as
900 object IDs, which must vary based on the hash algorithm.
901
902 Certain fixed values, such as hash sizes and common placeholder
903 object IDs, can be loaded with test_oid_init (described above).
904
905 - test_oid <key>
906
907 This function looks up a value for the hash algorithm in use, based
908 on the key given. The value must have been loaded using
909 test_oid_init or test_oid_cache. Providing an unknown key is an
910 error.
911
912 Prerequisites
913 -------------
914
915 These are the prerequisites that the test library predefines with
916 test_have_prereq.
917
918 See the prereq argument to the test_* functions in the "Test harness
919 library" section above and the "test_have_prereq" function for how to
920 use these, and "test_set_prereq" for how to define your own.
921
922 - PYTHON
923
924 Git wasn't compiled with NO_PYTHON=YesPlease. Wrap any tests that
925 need Python with this.
926
927 - PERL
928
929 Git wasn't compiled with NO_PERL=YesPlease.
930
931 Even without the PERL prerequisite, tests can assume there is a
932 usable perl interpreter at $PERL_PATH, though it need not be
933 particularly modern.
934
935 - POSIXPERM
936
937 The filesystem supports POSIX style permission bits.
938
939 - BSLASHPSPEC
940
941 Backslashes in pathspec are not directory separators. This is not
942 set on Windows. See 6fd1106a for details.
943
944 - EXECKEEPSPID
945
946 The process retains the same pid across exec(2). See fb9a2bea for
947 details.
948
949 - PIPE
950
951 The filesystem we're on supports creation of FIFOs (named pipes)
952 via mkfifo(1).
953
954 - SYMLINKS
955
956 The filesystem we're on supports symbolic links. E.g. a FAT
957 filesystem doesn't support these. See 704a3143 for details.
958
959 - SANITY
960
961 Test is not run by root user, and an attempt to write to an
962 unwritable file is expected to fail correctly.
963
964 - PCRE
965
966 Git was compiled with support for PCRE. Wrap any tests
967 that use git-grep --perl-regexp or git-grep -P in these.
968
969 - LIBPCRE1
970
971 Git was compiled with PCRE v1 support via
972 USE_LIBPCRE1=YesPlease. Wrap any PCRE using tests that for some
973 reason need v1 of the PCRE library instead of v2 in these.
974
975 - LIBPCRE2
976
977 Git was compiled with PCRE v2 support via
978 USE_LIBPCRE2=YesPlease. Wrap any PCRE using tests that for some
979 reason need v2 of the PCRE library instead of v1 in these.
980
981 - CASE_INSENSITIVE_FS
982
983 Test is run on a case insensitive file system.
984
985 - UTF8_NFD_TO_NFC
986
987 Test is run on a filesystem which converts decomposed utf-8 (nfd)
988 to precomposed utf-8 (nfc).
989
990 - PTHREADS
991
992 Git wasn't compiled with NO_PTHREADS=YesPlease.
993
994 Tips for Writing Tests
995 ----------------------
996
997 As with any programming projects, existing programs are the best
998 source of the information. However, do _not_ emulate
999 t0000-basic.sh when writing your tests. The test is special in
1000 that it tries to validate the very core of GIT. For example, it
1001 knows that there will be 256 subdirectories under .git/objects/,
1002 and it knows that the object ID of an empty tree is a certain
1003 40-byte string. This is deliberately done so in t0000-basic.sh
1004 because the things the very basic core test tries to achieve is
1005 to serve as a basis for people who are changing the GIT internal
1006 drastically. For these people, after making certain changes,
1007 not seeing failures from the basic test _is_ a failure. And
1008 such drastic changes to the core GIT that even changes these
1009 otherwise supposedly stable object IDs should be accompanied by
1010 an update to t0000-basic.sh.
1011
1012 However, other tests that simply rely on basic parts of the core
1013 GIT working properly should not have that level of intimate
1014 knowledge of the core GIT internals. If all the test scripts
1015 hardcoded the object IDs like t0000-basic.sh does, that defeats
1016 the purpose of t0000-basic.sh, which is to isolate that level of
1017 validation in one place. Your test also ends up needing
1018 updating when such a change to the internal happens, so do _not_
1019 do it and leave the low level of validation to t0000-basic.sh.
1020
1021 Test coverage
1022 -------------
1023
1024 You can use the coverage tests to find code paths that are not being
1025 used or properly exercised yet.
1026
1027 To do that, run the coverage target at the top-level (not in the t/
1028 directory):
1029
1030 make coverage
1031
1032 That'll compile Git with GCC's coverage arguments, and generate a test
1033 report with gcov after the tests finish. Running the coverage tests
1034 can take a while, since running the tests in parallel is incompatible
1035 with GCC's coverage mode.
1036
1037 After the tests have run you can generate a list of untested
1038 functions:
1039
1040 make coverage-untested-functions
1041
1042 You can also generate a detailed per-file HTML report using the
1043 Devel::Cover module. To install it do:
1044
1045 # On Debian or Ubuntu:
1046 sudo aptitude install libdevel-cover-perl
1047
1048 # From the CPAN with cpanminus
1049 curl -L http://cpanmin.us | perl - --sudo --self-upgrade
1050 cpanm --sudo Devel::Cover
1051
1052 Then, at the top-level:
1053
1054 make cover_db_html
1055
1056 That'll generate a detailed cover report in the "cover_db_html"
1057 directory, which you can then copy to a webserver, or inspect locally
1058 in a browser.