Merge branch 'rs/sha1-file-close-mapped-file-on-error'
[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 You can also set the GIT_TEST_INSTALLED environment variable to
190 the bindir of an existing git installation to test that installation.
191 You still need to have built this git sandbox, from which various
192 test-* support programs, templates, and perl libraries are used.
193 If your installed git is incomplete, it will silently test parts of
194 your built version instead.
195
196 When using GIT_TEST_INSTALLED, you can also set GIT_TEST_EXEC_PATH to
197 override the location of the dashed-form subcommands (what
198 GIT_EXEC_PATH would be used for during normal operation).
199 GIT_TEST_EXEC_PATH defaults to `$GIT_TEST_INSTALLED/git --exec-path`.
200
201
202 Skipping Tests
203 --------------
204
205 In some environments, certain tests have no way of succeeding
206 due to platform limitation, such as lack of 'unzip' program, or
207 filesystem that do not allow arbitrary sequence of non-NUL bytes
208 as pathnames.
209
210 You should be able to say something like
211
212 $ GIT_SKIP_TESTS=t9200.8 sh ./t9200-git-cvsexport-commit.sh
213
214 and even:
215
216 $ GIT_SKIP_TESTS='t[0-4]??? t91?? t9200.8' make
217
218 to omit such tests. The value of the environment variable is a
219 SP separated list of patterns that tells which tests to skip,
220 and either can match the "t[0-9]{4}" part to skip the whole
221 test, or t[0-9]{4} followed by ".$number" to say which
222 particular test to skip.
223
224 For an individual test suite --run could be used to specify that
225 only some tests should be run or that some tests should be
226 excluded from a run.
227
228 The argument for --run is a list of individual test numbers or
229 ranges with an optional negation prefix that define what tests in
230 a test suite to include in the run. A range is two numbers
231 separated with a dash and matches a range of tests with both ends
232 been included. You may omit the first or the second number to
233 mean "from the first test" or "up to the very last test"
234 respectively.
235
236 Optional prefix of '!' means that the test or a range of tests
237 should be excluded from the run.
238
239 If --run starts with an unprefixed number or range the initial
240 set of tests to run is empty. If the first item starts with '!'
241 all the tests are added to the initial set. After initial set is
242 determined every test number or range is added or excluded from
243 the set one by one, from left to right.
244
245 Individual numbers or ranges could be separated either by a space
246 or a comma.
247
248 For example, to run only tests up to a specific test (21), one
249 could do this:
250
251 $ sh ./t9200-git-cvsexport-commit.sh --run='1-21'
252
253 or this:
254
255 $ sh ./t9200-git-cvsexport-commit.sh --run='-21'
256
257 Common case is to run several setup tests (1, 2, 3) and then a
258 specific test (21) that relies on that setup:
259
260 $ sh ./t9200-git-cvsexport-commit.sh --run='1 2 3 21'
261
262 or:
263
264 $ sh ./t9200-git-cvsexport-commit.sh --run=1,2,3,21
265
266 or:
267
268 $ sh ./t9200-git-cvsexport-commit.sh --run='-3 21'
269
270 As noted above, the test set is built by going through the items
271 from left to right, so this:
272
273 $ sh ./t9200-git-cvsexport-commit.sh --run='1-4 !3'
274
275 will run tests 1, 2, and 4. Items that come later have higher
276 precedence. It means that this:
277
278 $ sh ./t9200-git-cvsexport-commit.sh --run='!3 1-4'
279
280 would just run tests from 1 to 4, including 3.
281
282 You may use negation with ranges. The following will run all
283 test in the test suite except from 7 up to 11:
284
285 $ sh ./t9200-git-cvsexport-commit.sh --run='!7-11'
286
287 Some tests in a test suite rely on the previous tests performing
288 certain actions, specifically some tests are designated as
289 "setup" test, so you cannot _arbitrarily_ disable one test and
290 expect the rest to function correctly.
291
292 --run is mostly useful when you want to focus on a specific test
293 and know what setup is needed for it. Or when you want to run
294 everything up to a certain test.
295
296
297 Running tests with special setups
298 ---------------------------------
299
300 The whole test suite could be run to test some special features
301 that cannot be easily covered by a few specific test cases. These
302 could be enabled by running the test suite with correct GIT_TEST_
303 environment set.
304
305 GIT_TEST_GETTEXT_POISON=<non-empty?> turns all strings marked for
306 translation into gibberish if non-empty (think "test -n"). Used for
307 spotting those tests that need to be marked with a C_LOCALE_OUTPUT
308 prerequisite when adding more strings for translation. See "Testing
309 marked strings" in po/README for details.
310
311 GIT_TEST_SPLIT_INDEX=<boolean> forces split-index mode on the whole
312 test suite. Accept any boolean values that are accepted by git-config.
313
314 GIT_TEST_FULL_IN_PACK_ARRAY=<boolean> exercises the uncommon
315 pack-objects code path where there are more than 1024 packs even if
316 the actual number of packs in repository is below this limit. Accept
317 any boolean values that are accepted by git-config.
318
319 GIT_TEST_OE_SIZE=<n> exercises the uncommon pack-objects code path
320 where we do not cache object size in memory and read it from existing
321 packs on demand. This normally only happens when the object size is
322 over 2GB. This variable forces the code path on any object larger than
323 <n> bytes.
324
325 GIT_TEST_OE_DELTA_SIZE=<n> exercises the uncommon pack-objects code
326 path where deltas larger than this limit require extra memory
327 allocation for bookkeeping.
328
329 GIT_TEST_VALIDATE_INDEX_CACHE_ENTRIES=<boolean> checks that cache-tree
330 records are valid when the index is written out or after a merge. This
331 is mostly to catch missing invalidation. Default is true.
332
333 GIT_TEST_COMMIT_GRAPH=<boolean>, when true, forces the commit-graph to
334 be written after every 'git commit' command, and overrides the
335 'core.commitGraph' setting to true.
336
337 GIT_TEST_FSMONITOR=$PWD/t7519/fsmonitor-all exercises the fsmonitor
338 code path for utilizing a file system monitor to speed up detecting
339 new or changed files.
340
341 GIT_TEST_INDEX_VERSION=<n> exercises the index read/write code path
342 for the index version specified. Can be set to any valid version
343 (currently 2, 3, or 4).
344
345 GIT_TEST_PRELOAD_INDEX=<boolean> exercises the preload-index code path
346 by overriding the minimum number of cache entries required per thread.
347
348 GIT_TEST_REBASE_USE_BUILTIN=<boolean>, when false, disables the
349 builtin version of git-rebase. See 'rebase.useBuiltin' in
350 git-config(1).
351
352 GIT_TEST_INDEX_THREADS=<n> enables exercising the multi-threaded loading
353 of the index for the whole test suite by bypassing the default number of
354 cache entries and thread minimums. Setting this to 1 will make the
355 index loading single threaded.
356
357 GIT_TEST_MULTI_PACK_INDEX=<boolean>, when true, forces the multi-pack-
358 index to be written after every 'git repack' command, and overrides the
359 'core.multiPackIndex' setting to true.
360
361 Naming Tests
362 ------------
363
364 The test files are named as:
365
366 tNNNN-commandname-details.sh
367
368 where N is a decimal digit.
369
370 First digit tells the family:
371
372 0 - the absolute basics and global stuff
373 1 - the basic commands concerning database
374 2 - the basic commands concerning the working tree
375 3 - the other basic commands (e.g. ls-files)
376 4 - the diff commands
377 5 - the pull and exporting commands
378 6 - the revision tree commands (even e.g. merge-base)
379 7 - the porcelainish commands concerning the working tree
380 8 - the porcelainish commands concerning forensics
381 9 - the git tools
382
383 Second digit tells the particular command we are testing.
384
385 Third digit (optionally) tells the particular switch or group of switches
386 we are testing.
387
388 If you create files under t/ directory (i.e. here) that is not
389 the top-level test script, never name the file to match the above
390 pattern. The Makefile here considers all such files as the
391 top-level test script and tries to run all of them. Care is
392 especially needed if you are creating a common test library
393 file, similar to test-lib.sh, because such a library file may
394 not be suitable for standalone execution.
395
396
397 Writing Tests
398 -------------
399
400 The test script is written as a shell script. It should start
401 with the standard "#!/bin/sh", and an
402 assignment to variable 'test_description', like this:
403
404 #!/bin/sh
405
406 test_description='xxx test (option --frotz)
407
408 This test registers the following structure in the cache
409 and tries to run git-ls-files with option --frotz.'
410
411
412 Source 'test-lib.sh'
413 --------------------
414
415 After assigning test_description, the test script should source
416 test-lib.sh like this:
417
418 . ./test-lib.sh
419
420 This test harness library does the following things:
421
422 - If the script is invoked with command line argument --help
423 (or -h), it shows the test_description and exits.
424
425 - Creates an empty test directory with an empty .git/objects database
426 and chdir(2) into it. This directory is 't/trash
427 directory.$test_name_without_dotsh', with t/ subject to change by
428 the --root option documented above.
429
430 - Defines standard test helper functions for your scripts to
431 use. These functions are designed to make all scripts behave
432 consistently when command line arguments --verbose (or -v),
433 --debug (or -d), and --immediate (or -i) is given.
434
435 Do's & don'ts
436 -------------
437
438 Here are a few examples of things you probably should and shouldn't do
439 when writing tests.
440
441 Here are the "do's:"
442
443 - Put all code inside test_expect_success and other assertions.
444
445 Even code that isn't a test per se, but merely some setup code
446 should be inside a test assertion.
447
448 - Chain your test assertions
449
450 Write test code like this:
451
452 git merge foo &&
453 git push bar &&
454 test ...
455
456 Instead of:
457
458 git merge hla
459 git push gh
460 test ...
461
462 That way all of the commands in your tests will succeed or fail. If
463 you must ignore the return value of something, consider using a
464 helper function (e.g. use sane_unset instead of unset, in order
465 to avoid unportable return value for unsetting a variable that was
466 already unset), or prepending the command with test_might_fail or
467 test_must_fail.
468
469 - Check the test coverage for your tests. See the "Test coverage"
470 below.
471
472 Don't blindly follow test coverage metrics; if a new function you added
473 doesn't have any coverage, then you're probably doing something wrong,
474 but having 100% coverage doesn't necessarily mean that you tested
475 everything.
476
477 Tests that are likely to smoke out future regressions are better
478 than tests that just inflate the coverage metrics.
479
480 - When a test checks for an absolute path that a git command generated,
481 construct the expected value using $(pwd) rather than $PWD,
482 $TEST_DIRECTORY, or $TRASH_DIRECTORY. It makes a difference on
483 Windows, where the shell (MSYS bash) mangles absolute path names.
484 For details, see the commit message of 4114156ae9.
485
486 - Remember that inside the <script> part, the standard output and
487 standard error streams are discarded, and the test harness only
488 reports "ok" or "not ok" to the end user running the tests. Under
489 --verbose, they are shown to help debug the tests.
490
491 And here are the "don'ts:"
492
493 - Don't exit() within a <script> part.
494
495 The harness will catch this as a programming error of the test.
496 Use test_done instead if you need to stop the tests early (see
497 "Skipping tests" below).
498
499 - Don't use '! git cmd' when you want to make sure the git command
500 exits with failure in a controlled way by calling "die()". Instead,
501 use 'test_must_fail git cmd'. This will signal a failure if git
502 dies in an unexpected way (e.g. segfault).
503
504 On the other hand, don't use test_must_fail for running regular
505 platform commands; just use '! cmd'. We are not in the business
506 of verifying that the world given to us sanely works.
507
508 - Don't feed the output of a git command to a pipe, as in:
509
510 git -C repo ls-files |
511 xargs -n 1 basename |
512 grep foo
513
514 which will discard git's exit code and may mask a crash. In the
515 above example, all exit codes are ignored except grep's.
516
517 Instead, write the output of that command to a temporary
518 file with ">" or assign it to a variable with "x=$(git ...)" rather
519 than pipe it.
520
521 - Don't use command substitution in a way that discards git's exit
522 code. When assigning to a variable, the exit code is not discarded,
523 e.g.:
524
525 x=$(git cat-file -p $sha) &&
526 ...
527
528 is OK because a crash in "git cat-file" will cause the "&&" chain
529 to fail, but:
530
531 test "refs/heads/foo" = "$(git symbolic-ref HEAD)"
532
533 is not OK and a crash in git could go undetected.
534
535 - Don't use perl without spelling it as "$PERL_PATH". This is to help
536 our friends on Windows where the platform Perl often adds CR before
537 the end of line, and they bundle Git with a version of Perl that
538 does not do so, whose path is specified with $PERL_PATH. Note that we
539 provide a "perl" function which uses $PERL_PATH under the hood, so
540 you do not need to worry when simply running perl in the test scripts
541 (but you do, for example, on a shebang line or in a sub script
542 created via "write_script").
543
544 - Don't use sh without spelling it as "$SHELL_PATH", when the script
545 can be misinterpreted by broken platform shell (e.g. Solaris).
546
547 - Don't chdir around in tests. It is not sufficient to chdir to
548 somewhere and then chdir back to the original location later in
549 the test, as any intermediate step can fail and abort the test,
550 causing the next test to start in an unexpected directory. Do so
551 inside a subshell if necessary.
552
553 - Don't save and verify the standard error of compound commands, i.e.
554 group commands, subshells, and shell functions (except test helper
555 functions like 'test_must_fail') like this:
556
557 ( cd dir && git cmd ) 2>error &&
558 test_cmp expect error
559
560 When running the test with '-x' tracing, then the trace of commands
561 executed in the compound command will be included in standard error
562 as well, quite possibly throwing off the subsequent checks examining
563 the output. Instead, save only the relevant git command's standard
564 error:
565
566 ( cd dir && git cmd 2>../error ) &&
567 test_cmp expect error
568
569 - Don't break the TAP output
570
571 The raw output from your test may be interpreted by a TAP harness. TAP
572 harnesses will ignore everything they don't know about, but don't step
573 on their toes in these areas:
574
575 - Don't print lines like "$x..$y" where $x and $y are integers.
576
577 - Don't print lines that begin with "ok" or "not ok".
578
579 TAP harnesses expect a line that begins with either "ok" and "not
580 ok" to signal a test passed or failed (and our harness already
581 produces such lines), so your script shouldn't emit such lines to
582 their output.
583
584 You can glean some further possible issues from the TAP grammar
585 (see https://metacpan.org/pod/TAP::Parser::Grammar#TAP-GRAMMAR)
586 but the best indication is to just run the tests with prove(1),
587 it'll complain if anything is amiss.
588
589
590 Skipping tests
591 --------------
592
593 If you need to skip tests you should do so by using the three-arg form
594 of the test_* functions (see the "Test harness library" section
595 below), e.g.:
596
597 test_expect_success PERL 'I need Perl' '
598 perl -e "hlagh() if unf_unf()"
599 '
600
601 The advantage of skipping tests like this is that platforms that don't
602 have the PERL and other optional dependencies get an indication of how
603 many tests they're missing.
604
605 If the test code is too hairy for that (i.e. does a lot of setup work
606 outside test assertions) you can also skip all remaining tests by
607 setting skip_all and immediately call test_done:
608
609 if ! test_have_prereq PERL
610 then
611 skip_all='skipping perl interface tests, perl not available'
612 test_done
613 fi
614
615 The string you give to skip_all will be used as an explanation for why
616 the test was skipped.
617
618 End with test_done
619 ------------------
620
621 Your script will be a sequence of tests, using helper functions
622 from the test harness library. At the end of the script, call
623 'test_done'.
624
625
626 Test harness library
627 --------------------
628
629 There are a handful helper functions defined in the test harness
630 library for your script to use.
631
632 - test_expect_success [<prereq>] <message> <script>
633
634 Usually takes two strings as parameters, and evaluates the
635 <script>. If it yields success, test is considered
636 successful. <message> should state what it is testing.
637
638 Example:
639
640 test_expect_success \
641 'git-write-tree should be able to write an empty tree.' \
642 'tree=$(git-write-tree)'
643
644 If you supply three parameters the first will be taken to be a
645 prerequisite; see the test_set_prereq and test_have_prereq
646 documentation below:
647
648 test_expect_success TTY 'git --paginate rev-list uses a pager' \
649 ' ... '
650
651 You can also supply a comma-separated list of prerequisites, in the
652 rare case where your test depends on more than one:
653
654 test_expect_success PERL,PYTHON 'yo dawg' \
655 ' test $(perl -E 'print eval "1 +" . qx[python -c "print 2"]') == "4" '
656
657 - test_expect_failure [<prereq>] <message> <script>
658
659 This is NOT the opposite of test_expect_success, but is used
660 to mark a test that demonstrates a known breakage. Unlike
661 the usual test_expect_success tests, which say "ok" on
662 success and "FAIL" on failure, this will say "FIXED" on
663 success and "still broken" on failure. Failures from these
664 tests won't cause -i (immediate) to stop.
665
666 Like test_expect_success this function can optionally use a three
667 argument invocation with a prerequisite as the first argument.
668
669 - test_debug <script>
670
671 This takes a single argument, <script>, and evaluates it only
672 when the test script is started with --debug command line
673 argument. This is primarily meant for use during the
674 development of a new test script.
675
676 - debug <git-command>
677
678 Run a git command inside a debugger. This is primarily meant for
679 use when debugging a failing test script.
680
681 - test_done
682
683 Your test script must have test_done at the end. Its purpose
684 is to summarize successes and failures in the test script and
685 exit with an appropriate error code.
686
687 - test_tick
688
689 Make commit and tag names consistent by setting the author and
690 committer times to defined state. Subsequent calls will
691 advance the times by a fixed amount.
692
693 - test_commit <message> [<filename> [<contents>]]
694
695 Creates a commit with the given message, committing the given
696 file with the given contents (default for both is to reuse the
697 message string), and adds a tag (again reusing the message
698 string as name). Calls test_tick to make the SHA-1s
699 reproducible.
700
701 - test_merge <message> <commit-or-tag>
702
703 Merges the given rev using the given message. Like test_commit,
704 creates a tag and calls test_tick before committing.
705
706 - test_set_prereq <prereq>
707
708 Set a test prerequisite to be used later with test_have_prereq. The
709 test-lib will set some prerequisites for you, see the
710 "Prerequisites" section below for a full list of these.
711
712 Others you can set yourself and use later with either
713 test_have_prereq directly, or the three argument invocation of
714 test_expect_success and test_expect_failure.
715
716 - test_have_prereq <prereq>
717
718 Check if we have a prerequisite previously set with test_set_prereq.
719 The most common way to use this explicitly (as opposed to the
720 implicit use when an argument is passed to test_expect_*) is to skip
721 all the tests at the start of the test script if we don't have some
722 essential prerequisite:
723
724 if ! test_have_prereq PERL
725 then
726 skip_all='skipping perl interface tests, perl not available'
727 test_done
728 fi
729
730 - test_external [<prereq>] <message> <external> <script>
731
732 Execute a <script> with an <external> interpreter (like perl). This
733 was added for tests like t9700-perl-git.sh which do most of their
734 work in an external test script.
735
736 test_external \
737 'GitwebCache::*FileCache*' \
738 perl "$TEST_DIRECTORY"/t9503/test_cache_interface.pl
739
740 If the test is outputting its own TAP you should set the
741 test_external_has_tap variable somewhere before calling the first
742 test_external* function. See t9700-perl-git.sh for an example.
743
744 # The external test will outputs its own plan
745 test_external_has_tap=1
746
747 - test_external_without_stderr [<prereq>] <message> <external> <script>
748
749 Like test_external but fail if there's any output on stderr,
750 instead of checking the exit code.
751
752 test_external_without_stderr \
753 'Perl API' \
754 perl "$TEST_DIRECTORY"/t9700/test.pl
755
756 - test_expect_code <exit-code> <command>
757
758 Run a command and ensure that it exits with the given exit code.
759 For example:
760
761 test_expect_success 'Merge with d/f conflicts' '
762 test_expect_code 1 git merge "merge msg" B master
763 '
764
765 - test_must_fail [<options>] <git-command>
766
767 Run a git command and ensure it fails in a controlled way. Use
768 this instead of "! <git-command>". When git-command dies due to a
769 segfault, test_must_fail diagnoses it as an error; "! <git-command>"
770 treats it as just another expected failure, which would let such a
771 bug go unnoticed.
772
773 Accepts the following options:
774
775 ok=<signal-name>[,<...>]:
776 Don't treat an exit caused by the given signal as error.
777 Multiple signals can be specified as a comma separated list.
778 Currently recognized signal names are: sigpipe, success.
779 (Don't use 'success', use 'test_might_fail' instead.)
780
781 - test_might_fail [<options>] <git-command>
782
783 Similar to test_must_fail, but tolerate success, too. Use this
784 instead of "<git-command> || :" to catch failures due to segv.
785
786 Accepts the same options as test_must_fail.
787
788 - test_cmp <expected> <actual>
789
790 Check whether the content of the <actual> file matches the
791 <expected> file. This behaves like "cmp" but produces more
792 helpful output when the test is run with "-v" option.
793
794 - test_cmp_rev <expected> <actual>
795
796 Check whether the <expected> rev points to the same commit as the
797 <actual> rev.
798
799 - test_line_count (= | -lt | -ge | ...) <length> <file>
800
801 Check whether a file has the length it is expected to.
802
803 - test_path_is_file <path> [<diagnosis>]
804 test_path_is_dir <path> [<diagnosis>]
805 test_path_is_missing <path> [<diagnosis>]
806
807 Check if the named path is a file, if the named path is a
808 directory, or if the named path does not exist, respectively,
809 and fail otherwise, showing the <diagnosis> text.
810
811 - test_when_finished <script>
812
813 Prepend <script> to a list of commands to run to clean up
814 at the end of the current test. If some clean-up command
815 fails, the test will not pass.
816
817 Example:
818
819 test_expect_success 'branch pointing to non-commit' '
820 git rev-parse HEAD^{tree} >.git/refs/heads/invalid &&
821 test_when_finished "git update-ref -d refs/heads/invalid" &&
822 ...
823 '
824
825 - test_write_lines <lines>
826
827 Write <lines> on standard output, one line per argument.
828 Useful to prepare multi-line files in a compact form.
829
830 Example:
831
832 test_write_lines a b c d e f g >foo
833
834 Is a more compact equivalent of:
835 cat >foo <<-EOF
836 a
837 b
838 c
839 d
840 e
841 f
842 g
843 EOF
844
845
846 - test_pause
847
848 This command is useful for writing and debugging tests and must be
849 removed before submitting. It halts the execution of the test and
850 spawns a shell in the trash directory. Exit the shell to continue
851 the test. Example:
852
853 test_expect_success 'test' '
854 git do-something >actual &&
855 test_pause &&
856 test_cmp expected actual
857 '
858
859 - test_ln_s_add <path1> <path2>
860
861 This function helps systems whose filesystem does not support symbolic
862 links. Use it to add a symbolic link entry to the index when it is not
863 important that the file system entry is a symbolic link, i.e., instead
864 of the sequence
865
866 ln -s foo bar &&
867 git add bar
868
869 Sometimes it is possible to split a test in a part that does not need
870 the symbolic link in the file system and a part that does; then only
871 the latter part need be protected by a SYMLINKS prerequisite (see below).
872
873 - test_oid_init
874
875 This function loads facts and useful object IDs related to the hash
876 algorithm(s) in use from the files in t/oid-info.
877
878 - test_oid_cache
879
880 This function reads per-hash algorithm information from standard
881 input (usually a heredoc) in the format described in
882 t/oid-info/README. This is useful for test-specific values, such as
883 object IDs, which must vary based on the hash algorithm.
884
885 Certain fixed values, such as hash sizes and common placeholder
886 object IDs, can be loaded with test_oid_init (described above).
887
888 - test_oid <key>
889
890 This function looks up a value for the hash algorithm in use, based
891 on the key given. The value must have been loaded using
892 test_oid_init or test_oid_cache. Providing an unknown key is an
893 error.
894
895 Prerequisites
896 -------------
897
898 These are the prerequisites that the test library predefines with
899 test_have_prereq.
900
901 See the prereq argument to the test_* functions in the "Test harness
902 library" section above and the "test_have_prereq" function for how to
903 use these, and "test_set_prereq" for how to define your own.
904
905 - PYTHON
906
907 Git wasn't compiled with NO_PYTHON=YesPlease. Wrap any tests that
908 need Python with this.
909
910 - PERL
911
912 Git wasn't compiled with NO_PERL=YesPlease.
913
914 Even without the PERL prerequisite, tests can assume there is a
915 usable perl interpreter at $PERL_PATH, though it need not be
916 particularly modern.
917
918 - POSIXPERM
919
920 The filesystem supports POSIX style permission bits.
921
922 - BSLASHPSPEC
923
924 Backslashes in pathspec are not directory separators. This is not
925 set on Windows. See 6fd1106a for details.
926
927 - EXECKEEPSPID
928
929 The process retains the same pid across exec(2). See fb9a2bea for
930 details.
931
932 - PIPE
933
934 The filesystem we're on supports creation of FIFOs (named pipes)
935 via mkfifo(1).
936
937 - SYMLINKS
938
939 The filesystem we're on supports symbolic links. E.g. a FAT
940 filesystem doesn't support these. See 704a3143 for details.
941
942 - SANITY
943
944 Test is not run by root user, and an attempt to write to an
945 unwritable file is expected to fail correctly.
946
947 - PCRE
948
949 Git was compiled with support for PCRE. Wrap any tests
950 that use git-grep --perl-regexp or git-grep -P in these.
951
952 - LIBPCRE1
953
954 Git was compiled with PCRE v1 support via
955 USE_LIBPCRE1=YesPlease. Wrap any PCRE using tests that for some
956 reason need v1 of the PCRE library instead of v2 in these.
957
958 - LIBPCRE2
959
960 Git was compiled with PCRE v2 support via
961 USE_LIBPCRE2=YesPlease. Wrap any PCRE using tests that for some
962 reason need v2 of the PCRE library instead of v1 in these.
963
964 - CASE_INSENSITIVE_FS
965
966 Test is run on a case insensitive file system.
967
968 - UTF8_NFD_TO_NFC
969
970 Test is run on a filesystem which converts decomposed utf-8 (nfd)
971 to precomposed utf-8 (nfc).
972
973 - PTHREADS
974
975 Git wasn't compiled with NO_PTHREADS=YesPlease.
976
977 Tips for Writing Tests
978 ----------------------
979
980 As with any programming projects, existing programs are the best
981 source of the information. However, do _not_ emulate
982 t0000-basic.sh when writing your tests. The test is special in
983 that it tries to validate the very core of GIT. For example, it
984 knows that there will be 256 subdirectories under .git/objects/,
985 and it knows that the object ID of an empty tree is a certain
986 40-byte string. This is deliberately done so in t0000-basic.sh
987 because the things the very basic core test tries to achieve is
988 to serve as a basis for people who are changing the GIT internal
989 drastically. For these people, after making certain changes,
990 not seeing failures from the basic test _is_ a failure. And
991 such drastic changes to the core GIT that even changes these
992 otherwise supposedly stable object IDs should be accompanied by
993 an update to t0000-basic.sh.
994
995 However, other tests that simply rely on basic parts of the core
996 GIT working properly should not have that level of intimate
997 knowledge of the core GIT internals. If all the test scripts
998 hardcoded the object IDs like t0000-basic.sh does, that defeats
999 the purpose of t0000-basic.sh, which is to isolate that level of
1000 validation in one place. Your test also ends up needing
1001 updating when such a change to the internal happens, so do _not_
1002 do it and leave the low level of validation to t0000-basic.sh.
1003
1004 Test coverage
1005 -------------
1006
1007 You can use the coverage tests to find code paths that are not being
1008 used or properly exercised yet.
1009
1010 To do that, run the coverage target at the top-level (not in the t/
1011 directory):
1012
1013 make coverage
1014
1015 That'll compile Git with GCC's coverage arguments, and generate a test
1016 report with gcov after the tests finish. Running the coverage tests
1017 can take a while, since running the tests in parallel is incompatible
1018 with GCC's coverage mode.
1019
1020 After the tests have run you can generate a list of untested
1021 functions:
1022
1023 make coverage-untested-functions
1024
1025 You can also generate a detailed per-file HTML report using the
1026 Devel::Cover module. To install it do:
1027
1028 # On Debian or Ubuntu:
1029 sudo aptitude install libdevel-cover-perl
1030
1031 # From the CPAN with cpanminus
1032 curl -L http://cpanmin.us | perl - --sudo --self-upgrade
1033 cpanm --sudo Devel::Cover
1034
1035 Then, at the top-level:
1036
1037 make cover_db_html
1038
1039 That'll generate a detailed cover report in the "cover_db_html"
1040 directory, which you can then copy to a webserver, or inspect locally
1041 in a browser.