t/t7800-difftool.sh: Skip with prereq on no PERL
[git/git.git] / t / README
CommitLineData
986aa7f1
JH
1Core GIT Tests
2==============
3
4This directory holds many test scripts for core GIT tools. The
5first part of this short document describes how to run the tests
6and read their output.
7
8When fixing the tools or adding enhancements, you are strongly
9encouraged to add tests in this directory to cover what you are
10trying to fix or enhance. The later part of this short document
11describes how your test scripts should be organized.
12
13
14Running Tests
15-------------
16
17The easiest way to run tests is to say "make". This runs all
18the tests.
19
20 *** t0000-basic.sh ***
5099b99d
ÆAB
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
986aa7f1 24 ...
5099b99d
ÆAB
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
35Since the tests all output TAP (see http://testanything.org) they can
85b0b34e 36be run with any TAP harness. Here's an example of parallel testing
5099b99d
ÆAB
37powered 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
47prove 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
986aa7f1 52
5099b99d 53You can also run each test individually from command line, like this:
986aa7f1 54
5099b99d
ÆAB
55 $ sh ./t3010-ls-files-killed-modified.sh
56 ok 1 - git update-index --add to add various paths.
57 ok 2 - git ls-files -k to show killed files.
58 ok 3 - validate git ls-files -k output.
59 ok 4 - git ls-files -m to show modified files.
60 ok 5 - validate git ls-files -m output.
61 # passed all 5 test(s)
62 1..5
986aa7f1
JH
63
64You can pass --verbose (or -v), --debug (or -d), and --immediate
4e1be63c
JS
65(or -i) command line argument to the test, or by setting GIT_TEST_OPTS
66appropriately before running "make".
986aa7f1
JH
67
68--verbose::
69 This makes the test more verbose. Specifically, the
70 command being run and their output if any are also
71 output.
72
73--debug::
74 This may help the person who is developing a new test.
75 It causes the command defined with test_debug to run.
76
77--immediate::
78 This causes the test to immediately exit upon the first
79 failed test.
80
5e2c08c6
LW
81--long-tests::
82 This causes additional long-running tests to be run (where
83 available), for more exhaustive testing.
84
4e1be63c
JS
85--valgrind::
86 Execute all Git binaries with valgrind and exit with status
87 126 on errors (just like regular tests, this will only stop
88 the test script when running under -i). Valgrind errors
89 go to stderr, so you might want to pass the -v option, too.
986aa7f1 90
3da93652
JS
91 Since it makes no sense to run the tests with --valgrind and
92 not see any output, this option implies --verbose. For
93 convenience, it also implies --tee.
94
44138559
JS
95--tee::
96 In addition to printing the test output to the terminal,
97 write it to files named 't/test-results/$TEST_NAME.out'.
98 As the names depend on the tests' file names, it is safe to
99 run the tests with this option in parallel.
100
e4597aae
MO
101--with-dashes::
102 By default tests are run without dashed forms of
103 commands (like git-commit) in the PATH (it only uses
104 wrappers from ../bin-wrappers). Use this option to include
105 the build directory (..) in the PATH, which contains all
106 the dashed forms of commands. This option is currently
107 implied by other options like --valgrind and
108 GIT_TEST_INSTALLED.
109
0d4dbcd3
TR
110--root=<directory>::
111 Create "trash" directories used to store all temporary data during
112 testing under <directory>, instead of the t/ directory.
113 Using this option with a RAM-based filesystem (such as tmpfs)
114 can massively speed up the test suite.
115
e160da7f
MO
116You can also set the GIT_TEST_INSTALLED environment variable to
117the bindir of an existing git installation to test that installation.
118You still need to have built this git sandbox, from which various
119test-* support programs, templates, and perl libraries are used.
120If your installed git is incomplete, it will silently test parts of
121your built version instead.
122
123When using GIT_TEST_INSTALLED, you can also set GIT_TEST_EXEC_PATH to
124override the location of the dashed-form subcommands (what
125GIT_EXEC_PATH would be used for during normal operation).
126GIT_TEST_EXEC_PATH defaults to `$GIT_TEST_INSTALLED/git --exec-path`.
127
128
fbd458a3
JN
129Skipping Tests
130--------------
131
132In some environments, certain tests have no way of succeeding
133due to platform limitation, such as lack of 'unzip' program, or
134filesystem that do not allow arbitrary sequence of non-NUL bytes
135as pathnames.
136
137You should be able to say something like
138
139 $ GIT_SKIP_TESTS=t9200.8 sh ./t9200-git-cvsexport-commit.sh
140
141and even:
142
143 $ GIT_SKIP_TESTS='t[0-4]??? t91?? t9200.8' make
144
145to omit such tests. The value of the environment variable is a
146SP separated list of patterns that tells which tests to skip,
147and either can match the "t[0-9]{4}" part to skip the whole
148test, or t[0-9]{4} followed by ".$number" to say which
149particular test to skip.
150
151Note that some tests in the existing test suite rely on previous
152test item, so you cannot arbitrarily disable one and expect the
153remainder of test to check what the test originally was intended
154to check.
155
156
f50c9f76
PB
157Naming Tests
158------------
159
160The test files are named as:
161
162 tNNNN-commandname-details.sh
163
164where N is a decimal digit.
165
166First digit tells the family:
167
168 0 - the absolute basics and global stuff
169 1 - the basic commands concerning database
170 2 - the basic commands concerning the working tree
171 3 - the other basic commands (e.g. ls-files)
172 4 - the diff commands
173 5 - the pull and exporting commands
174 6 - the revision tree commands (even e.g. merge-base)
8f4a9b62 175 7 - the porcelainish commands concerning the working tree
8757749e
JN
176 8 - the porcelainish commands concerning forensics
177 9 - the git tools
f50c9f76
PB
178
179Second digit tells the particular command we are testing.
180
181Third digit (optionally) tells the particular switch or group of switches
182we are testing.
183
77656600
JH
184If you create files under t/ directory (i.e. here) that is not
185the top-level test script, never name the file to match the above
186pattern. The Makefile here considers all such files as the
187top-level test script and tries to run all of them. A care is
188especially needed if you are creating a common test library
189file, similar to test-lib.sh, because such a library file may
190not be suitable for standalone execution.
191
f50c9f76 192
986aa7f1
JH
193Writing Tests
194-------------
195
196The test script is written as a shell script. It should start
197with the standard "#!/bin/sh" with copyright notices, and an
198assignment to variable 'test_description', like this:
199
200 #!/bin/sh
201 #
202 # Copyright (c) 2005 Junio C Hamano
203 #
204
14cd1ff3 205 test_description='xxx test (option --frotz)
986aa7f1
JH
206
207 This test registers the following structure in the cache
208 and tries to run git-ls-files with option --frotz.'
209
f50c9f76 210
986aa7f1
JH
211Source 'test-lib.sh'
212--------------------
213
214After assigning test_description, the test script should source
215test-lib.sh like this:
216
217 . ./test-lib.sh
218
219This test harness library does the following things:
220
221 - If the script is invoked with command line argument --help
222 (or -h), it shows the test_description and exits.
223
e1ca1c9d
ÆAB
224 - Creates an empty test directory with an empty .git/objects database
225 and chdir(2) into it. This directory is 't/trash
226 directory.$test_name_without_dotsh', with t/ subject to change by
227 the --root option documented above.
986aa7f1
JH
228
229 - Defines standard test helper functions for your scripts to
230 use. These functions are designed to make all scripts behave
231 consistently when command line arguments --verbose (or -v),
232 --debug (or -d), and --immediate (or -i) is given.
233
20873f45
ÆAB
234Do's, don'ts & things to keep in mind
235-------------------------------------
236
6fd45295 237Here are a few examples of things you probably should and shouldn't do
20873f45
ÆAB
238when writing tests.
239
240Do:
241
6fd45295 242 - Put all code inside test_expect_success and other assertions.
20873f45
ÆAB
243
244 Even code that isn't a test per se, but merely some setup code
6fd45295 245 should be inside a test assertion.
20873f45
ÆAB
246
247 - Chain your test assertions
248
249 Write test code like this:
250
251 git merge foo &&
252 git push bar &&
253 test ...
254
255 Instead of:
256
257 git merge hla
258 git push gh
259 test ...
260
261 That way all of the commands in your tests will succeed or fail. If
bdcaa325
JN
262 you must ignore the return value of something (e.g., the return
263 after unsetting a variable that was already unset is unportable) it's
264 best to indicate so explicitly with a semicolon:
20873f45 265
bdcaa325 266 unset HLAGH;
20873f45
ÆAB
267 git merge hla &&
268 git push gh &&
269 test ...
270
0c357544
ÆAB
271 - Check the test coverage for your tests. See the "Test coverage"
272 below.
273
e8b55f5c
ÆAB
274 Don't blindly follow test coverage metrics, they're a good way to
275 spot if you've missed something. If a new function you added
276 doesn't have any coverage you're probably doing something wrong,
277 but having 100% coverage doesn't necessarily mean that you tested
278 everything.
279
280 Tests that are likely to smoke out future regressions are better
281 than tests that just inflate the coverage metrics.
282
20873f45
ÆAB
283Don't:
284
285 - exit() within a <script> part.
286
287 The harness will catch this as a programming error of the test.
288 Use test_done instead if you need to stop the tests early (see
289 "Skipping tests" below).
290
291 - Break the TAP output
292
6fd45295
JH
293 The raw output from your test may be interpreted by a TAP harness. TAP
294 harnesses will ignore everything they don't know about, but don't step
295 on their toes in these areas:
20873f45
ÆAB
296
297 - Don't print lines like "$x..$y" where $x and $y are integers.
298
299 - Don't print lines that begin with "ok" or "not ok".
300
6fd45295 301 TAP harnesses expect a line that begins with either "ok" and "not
20873f45
ÆAB
302 ok" to signal a test passed or failed (and our harness already
303 produces such lines), so your script shouldn't emit such lines to
304 their output.
305
306 You can glean some further possible issues from the TAP grammar
307 (see http://search.cpan.org/perldoc?TAP::Parser::Grammar#TAP_Grammar)
308 but the best indication is to just run the tests with prove(1),
309 it'll complain if anything is amiss.
310
311Keep in mind:
312
6fd45295 313 - Inside <script> part, the standard output and standard error
20873f45
ÆAB
314 streams are discarded, and the test harness only reports "ok" or
315 "not ok" to the end user running the tests. Under --verbose, they
316 are shown to help debugging the tests.
317
318
b5500d16
ÆAB
319Skipping tests
320--------------
321
322If you need to skip all the remaining tests you should set skip_all
323and immediately call test_done. The string you give to skip_all will
324be used as an explanation for why the test was skipped. for instance:
325
326 if ! test_have_prereq PERL
327 then
328 skip_all='skipping perl interface tests, perl not available'
329 test_done
330 fi
14cd1ff3 331
986aa7f1
JH
332End with test_done
333------------------
334
335Your script will be a sequence of tests, using helper functions
336from the test harness library. At the end of the script, call
337'test_done'.
338
339
340Test harness library
341--------------------
342
343There are a handful helper functions defined in the test harness
344library for your script to use.
345
9a897893 346 - test_expect_success [<prereq>] <message> <script>
986aa7f1 347
9a897893 348 Usually takes two strings as parameter, and evaluates the
986aa7f1
JH
349 <script>. If it yields success, test is considered
350 successful. <message> should state what it is testing.
351
352 Example:
353
354 test_expect_success \
355 'git-write-tree should be able to write an empty tree.' \
356 'tree=$(git-write-tree)'
357
9a897893
ÆAB
358 If you supply three parameters the first will be taken to be a
359 prerequisite, see the test_set_prereq and test_have_prereq
360 documentation below:
361
362 test_expect_success TTY 'git --paginate rev-list uses a pager' \
363 ' ... '
364
93a57246
ÆAB
365 You can also supply a comma-separated list of prerequisites, in the
366 rare case where your test depends on more than one:
367
368 test_expect_success PERL,PYTHON 'yo dawg' \
369 ' test $(perl -E 'print eval "1 +" . qx[python -c "print 2"]') == "4" '
370
9a897893 371 - test_expect_failure [<prereq>] <message> <script>
986aa7f1 372
41ac414e
JH
373 This is NOT the opposite of test_expect_success, but is used
374 to mark a test that demonstrates a known breakage. Unlike
375 the usual test_expect_success tests, which say "ok" on
376 success and "FAIL" on failure, this will say "FIXED" on
377 success and "still broken" on failure. Failures from these
378 tests won't cause -i (immediate) to stop.
986aa7f1 379
9a897893
ÆAB
380 Like test_expect_success this function can optionally use a three
381 argument invocation with a prerequisite as the first argument.
382
97d9fd92
ÆAB
383 - test_expect_code [<prereq>] <code> <message> <script>
384
385 Analogous to test_expect_success, but pass the test if it exits
386 with a given exit <code>
387
388 test_expect_code 1 'Merge with d/f conflicts' 'git merge "merge msg" B master'
389
986aa7f1
JH
390 - test_debug <script>
391
392 This takes a single argument, <script>, and evaluates it only
393 when the test script is started with --debug command line
394 argument. This is primarily meant for use during the
395 development of a new test script.
396
397 - test_done
398
399 Your test script must have test_done at the end. Its purpose
400 is to summarize successes and failures in the test script and
401 exit with an appropriate error code.
402
00884968
JS
403 - test_tick
404
405 Make commit and tag names consistent by setting the author and
406 committer times to defined stated. Subsequent calls will
407 advance the times by a fixed amount.
408
409 - test_commit <message> [<filename> [<contents>]]
410
411 Creates a commit with the given message, committing the given
412 file with the given contents (default for both is to reuse the
413 message string), and adds a tag (again reusing the message
414 string as name). Calls test_tick to make the SHA-1s
415 reproducible.
416
417 - test_merge <message> <commit-or-tag>
418
419 Merges the given rev using the given message. Like test_commit,
420 creates a tag and calls test_tick before committing.
986aa7f1 421
9a897893
ÆAB
422 - test_set_prereq SOME_PREREQ
423
424 Set a test prerequisite to be used later with test_have_prereq. The
be53deef
ÆAB
425 test-lib will set some prerequisites for you, see the
426 "Prerequisites" section below for a full list of these.
427
428 Others you can set yourself and use later with either
429 test_have_prereq directly, or the three argument invocation of
430 test_expect_success and test_expect_failure.
9a897893
ÆAB
431
432 - test_have_prereq SOME PREREQ
433
434 Check if we have a prerequisite previously set with
435 test_set_prereq. The most common use of this directly is to skip
436 all the tests if we don't have some essential prerequisite:
437
438 if ! test_have_prereq PERL
439 then
440 skip_all='skipping perl interface tests, perl not available'
441 test_done
442 fi
443
2fac6a4b
ÆAB
444 - test_external [<prereq>] <message> <external> <script>
445
446 Execute a <script> with an <external> interpreter (like perl). This
447 was added for tests like t9700-perl-git.sh which do most of their
448 work in an external test script.
449
450 test_external \
451 'GitwebCache::*FileCache*' \
452 "$PERL_PATH" "$TEST_DIRECTORY"/t9503/test_cache_interface.pl
453
454 If the test is outputting its own TAP you should set the
455 test_external_has_tap variable somewhere before calling the first
456 test_external* function. See t9700-perl-git.sh for an example.
457
458 # The external test will outputs its own plan
459 test_external_has_tap=1
460
461 - test_external_without_stderr [<prereq>] <message> <external> <script>
462
463 Like test_external but fail if there's any output on stderr,
464 instead of checking the exit code.
465
466 test_external_without_stderr \
467 'Perl API' \
468 "$PERL_PATH" "$TEST_DIRECTORY"/t9700/test.pl
469
c9667456
JN
470 - test_must_fail <git-command>
471
472 Run a git command and ensure it fails in a controlled way. Use
971ecbd1
BC
473 this instead of "! <git-command>". When git-command dies due to a
474 segfault, test_must_fail diagnoses it as an error; "! <git-command>"
475 treats it as just another expected failure, which would let such a
476 bug go unnoticed.
c9667456
JN
477
478 - test_might_fail <git-command>
479
480 Similar to test_must_fail, but tolerate success, too. Use this
481 instead of "<git-command> || :" to catch failures due to segv.
482
483 - test_cmp <expected> <actual>
484
485 Check whether the content of the <actual> file matches the
486 <expected> file. This behaves like "cmp" but produces more
487 helpful output when the test is run with "-v" option.
488
489 - test_when_finished <script>
490
491 Prepend <script> to a list of commands to run to clean up
492 at the end of the current test. If some clean-up command
493 fails, the test will not pass.
494
495 Example:
496
497 test_expect_success 'branch pointing to non-commit' '
498 git rev-parse HEAD^{tree} >.git/refs/heads/invalid &&
499 test_when_finished "git update-ref -d refs/heads/invalid" &&
500 ...
501 '
502
be53deef
ÆAB
503Prerequisites
504-------------
505
506These are the prerequisites that the test library predefines with
507test_have_prereq.
508
509See the prereq argument to the test_* functions in the "Test harness
510library" section above and the "test_have_prereq" function for how to
511use these, and "test_set_prereq" for how to define your own.
512
513 - PERL & PYTHON
514
515 Git wasn't compiled with NO_PERL=YesPlease or
516 NO_PYTHON=YesPlease. Wrap any tests that need Perl or Python in
517 these.
518
519 - POSIXPERM
520
521 The filesystem supports POSIX style permission bits.
522
523 - BSLASHPSPEC
524
525 Backslashes in pathspec are not directory separators. This is not
526 set on Windows. See 6fd1106a for details.
527
528 - EXECKEEPSPID
529
530 The process retains the same pid across exec(2). See fb9a2bea for
531 details.
532
533 - SYMLINKS
534
535 The filesystem we're on supports symbolic links. E.g. a FAT
536 filesystem doesn't support these. See 704a3143 for details.
2fac6a4b 537
c91cfd19
ÆAB
538 - SANITY
539
540 Test is not run by root user, and an attempt to write to an
541 unwritable file is expected to fail correctly.
542
986aa7f1
JH
543Tips for Writing Tests
544----------------------
545
546As with any programming projects, existing programs are the best
547source of the information. However, do _not_ emulate
548t0000-basic.sh when writing your tests. The test is special in
549that it tries to validate the very core of GIT. For example, it
550knows that there will be 256 subdirectories under .git/objects/,
551and it knows that the object ID of an empty tree is a certain
55240-byte string. This is deliberately done so in t0000-basic.sh
553because the things the very basic core test tries to achieve is
554to serve as a basis for people who are changing the GIT internal
555drastically. For these people, after making certain changes,
556not seeing failures from the basic test _is_ a failure. And
557such drastic changes to the core GIT that even changes these
558otherwise supposedly stable object IDs should be accompanied by
559an update to t0000-basic.sh.
560
561However, other tests that simply rely on basic parts of the core
562GIT working properly should not have that level of intimate
563knowledge of the core GIT internals. If all the test scripts
564hardcoded the object IDs like t0000-basic.sh does, that defeats
565the purpose of t0000-basic.sh, which is to isolate that level of
566validation in one place. Your test also ends up needing
567updating when such a change to the internal happens, so do _not_
568do it and leave the low level of validation to t0000-basic.sh.
d15e9ebc 569
0c357544
ÆAB
570Test coverage
571-------------
572
573You can use the coverage tests to find code paths that are not being
574used or properly exercised yet.
575
576To do that, run the coverage target at the top-level (not in the t/
577directory):
578
579 make coverage
580
581That'll compile Git with GCC's coverage arguments, and generate a test
582report with gcov after the tests finish. Running the coverage tests
583can take a while, since running the tests in parallel is incompatible
584with GCC's coverage mode.
585
586After the tests have run you can generate a list of untested
587functions:
588
589 make coverage-untested-functions
590
591You can also generate a detailed per-file HTML report using the
592Devel::Cover module. To install it do:
593
594 # On Debian or Ubuntu:
595 sudo aptitude install libdevel-cover-perl
596
597 # From the CPAN with cpanminus
598 curl -L http://cpanmin.us | perl - --sudo --self-upgrade
599 cpanm --sudo Devel::Cover
600
601Then, at the top-level:
602
603 make cover_db_html
604
605That'll generate a detailed cover report in the "cover_db_html"
606directory, which you can then copy to a webserver, or inspect locally
607in a browser.
608
d15e9ebc
ÆAB
609Smoke testing
610-------------
611
612The Git test suite has support for smoke testing. Smoke testing is
613when you submit the results of a test run to a central server for
614analysis and aggregation.
615
616Running a smoke tester is an easy and valuable way of contributing to
617Git development, particularly if you have access to an uncommon OS on
618obscure hardware.
619
620After building Git you can generate a smoke report like this in the
621"t" directory:
622
623 make clean smoke
624
625You can also pass arguments via the environment. This should make it
626faster:
627
628 GIT_TEST_OPTS='--root=/dev/shm' TEST_JOBS=10 make clean smoke
629
630The "smoke" target will run the Git test suite with Perl's
631"TAP::Harness" module, and package up the results in a .tar.gz archive
632with "TAP::Harness::Archive". The former is included with Perl v5.10.1
633or later, but you'll need to install the latter from the CPAN. See the
634"Test coverage" section above for how you might do that.
635
636Once the "smoke" target finishes you'll see a message like this:
637
638 TAP Archive created at <path to git>/t/test-results/git-smoke.tar.gz
639
640To upload the smoke report you need to have curl(1) installed, then
641do:
642
643 make smoke_report
644
645To upload the report anonymously. Hopefully that'll return something
646like "Reported #7 added.".
647
648If you're going to be uploading reports frequently please request a
649user account by E-Mailing gitsmoke@v.nix.is. Once you have a username
650and password you'll be able to do:
651
652 SMOKE_USERNAME=<username> SMOKE_PASSWORD=<password> make smoke_report
653
e38efac8
ÆAB
654You can also add an additional comment to attach to the report, and/or
655a comma separated list of tags:
656
657 SMOKE_USERNAME=<username> SMOKE_PASSWORD=<password> \
658 SMOKE_COMMENT=<comment> SMOKE_TAGS=<tags> \
659 make smoke_report
660
d15e9ebc
ÆAB
661Once the report is uploaded it'll be made available at
662http://smoke.git.nix.is, here's an overview of Recent Smoke Reports
663for Git:
664
665 http://smoke.git.nix.is/app/projects/smoke_reports/1
666
667The reports will also be mirrored to GitHub every few hours:
668
669 http://github.com/gitsmoke/smoke-reports
670
671The Smolder SQLite database is also mirrored and made available for
672download:
673
674 http://github.com/gitsmoke/smoke-database
675
676Note that the database includes hashed (with crypt()) user passwords
677and E-Mail addresses. Don't use a valuable password for the smoke
678service if you have an account, or an E-Mail address you don't want to
679be publicly known. The user accounts are just meant to be convenient
680labels, they're not meant to be secure.