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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 ***
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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 ...
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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
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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
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53You can give DEFAULT_TEST_TARGET=prove on the make command (or define it
54in config.mak) to cause "make test" to run tests under prove.
55GIT_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
5099b99d 59You can also run each test individually from command line, like this:
986aa7f1 60
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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
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69
70You can pass --verbose (or -v), --debug (or -d), and --immediate
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71(or -i) command line argument to the test, or by setting GIT_TEST_OPTS
72appropriately before running "make".
986aa7f1 73
5e3b4fce 74-v::
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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
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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
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85-x::
86 Turn on shell tracing (i.e., `set -x`) during the tests
94201a2b 87 themselves. Implies `--verbose`.
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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.
a136f6d8 91
5e3b4fce 92-d::
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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.
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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.
986aa7f1 100
5e3b4fce 101-i::
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102--immediate::
103 This causes the test to immediately exit upon the first
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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.
986aa7f1 108
5e3b4fce 109-l::
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110--long-tests::
111 This causes additional long-running tests to be run (where
112 available), for more exhaustive testing.
113
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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
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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).
986aa7f1 124
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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
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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
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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
952af351 139 Note that memcheck is run with the option --leak-check=no,
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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
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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
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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
a5f52c6d 157-V::
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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
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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
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173--no-bin-wrappers::
174 By default, the test suite uses the wrappers in
175 `../bin-wrappers/` to execute `git` and friends. With this option,
176 `../git` and friends are run directly. This is not recommended
177 in general, as the wrappers contain safeguards to ensure that no
178 files from an installed Git are used, but can speed up test runs
179 especially on platforms where running shell scripts is expensive
180 (most notably, Windows).
181
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182--root=<directory>::
183 Create "trash" directories used to store all temporary data during
184 testing under <directory>, instead of the t/ directory.
185 Using this option with a RAM-based filesystem (such as tmpfs)
186 can massively speed up the test suite.
187
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188--chain-lint::
189--no-chain-lint::
190 If --chain-lint is enabled, the test harness will check each
191 test to make sure that it properly "&&-chains" all commands (so
192 that a failure in the middle does not go unnoticed by the final
193 exit code of the test). This check is performed in addition to
194 running the tests themselves. You may also enable or disable
195 this feature by setting the GIT_TEST_CHAIN_LINT environment
196 variable to "1" or "0", respectively.
197
fb7d1e3a 198--stress::
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199 Run the test script repeatedly in multiple parallel jobs until
200 one of them fails. Useful for reproducing rare failures in
201 flaky tests. The number of parallel jobs is, in order of
f5457371 202 precedence: the value of the GIT_TEST_STRESS_LOAD
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203 environment variable, or twice the number of available
204 processors (as shown by the 'getconf' utility), or 8.
205 Implies `--verbose -x --immediate` to get the most information
206 about the failure. Note that the verbose output of each test
207 job is saved to 't/test-results/$TEST_NAME.stress-<nr>.out',
208 and only the output of the failed test job is shown on the
209 terminal. The names of the trash directories get a
210 '.stress-<nr>' suffix, and the trash directory of the failed
211 test job is renamed to end with a '.stress-failed' suffix.
212
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213--stress-jobs=<N>::
214 Override the number of parallel jobs. Implies `--stress`.
215
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216--stress-limit=<N>::
217 When combined with --stress run the test script repeatedly
218 this many times in each of the parallel jobs or until one of
de69e6f6 219 them fails, whichever comes first. Implies `--stress`.
76e27fbf 220
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221You can also set the GIT_TEST_INSTALLED environment variable to
222the bindir of an existing git installation to test that installation.
223You still need to have built this git sandbox, from which various
224test-* support programs, templates, and perl libraries are used.
225If your installed git is incomplete, it will silently test parts of
226your built version instead.
227
228When using GIT_TEST_INSTALLED, you can also set GIT_TEST_EXEC_PATH to
229override the location of the dashed-form subcommands (what
230GIT_EXEC_PATH would be used for during normal operation).
231GIT_TEST_EXEC_PATH defaults to `$GIT_TEST_INSTALLED/git --exec-path`.
232
233
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234Skipping Tests
235--------------
236
237In some environments, certain tests have no way of succeeding
238due to platform limitation, such as lack of 'unzip' program, or
239filesystem that do not allow arbitrary sequence of non-NUL bytes
240as pathnames.
241
242You should be able to say something like
243
244 $ GIT_SKIP_TESTS=t9200.8 sh ./t9200-git-cvsexport-commit.sh
245
246and even:
247
248 $ GIT_SKIP_TESTS='t[0-4]??? t91?? t9200.8' make
249
250to omit such tests. The value of the environment variable is a
251SP separated list of patterns that tells which tests to skip,
252and either can match the "t[0-9]{4}" part to skip the whole
253test, or t[0-9]{4} followed by ".$number" to say which
254particular test to skip.
255
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256For an individual test suite --run could be used to specify that
257only some tests should be run or that some tests should be
258excluded from a run.
259
260The argument for --run is a list of individual test numbers or
261ranges with an optional negation prefix that define what tests in
262a test suite to include in the run. A range is two numbers
263separated with a dash and matches a range of tests with both ends
264been included. You may omit the first or the second number to
265mean "from the first test" or "up to the very last test"
266respectively.
267
268Optional prefix of '!' means that the test or a range of tests
269should be excluded from the run.
270
271If --run starts with an unprefixed number or range the initial
272set of tests to run is empty. If the first item starts with '!'
273all the tests are added to the initial set. After initial set is
274determined every test number or range is added or excluded from
275the set one by one, from left to right.
276
277Individual numbers or ranges could be separated either by a space
278or a comma.
279
280For example, to run only tests up to a specific test (21), one
281could do this:
282
283 $ sh ./t9200-git-cvsexport-commit.sh --run='1-21'
284
285or this:
286
287 $ sh ./t9200-git-cvsexport-commit.sh --run='-21'
288
289Common case is to run several setup tests (1, 2, 3) and then a
290specific test (21) that relies on that setup:
291
292 $ sh ./t9200-git-cvsexport-commit.sh --run='1 2 3 21'
293
294or:
295
296 $ sh ./t9200-git-cvsexport-commit.sh --run=1,2,3,21
297
298or:
299
300 $ sh ./t9200-git-cvsexport-commit.sh --run='-3 21'
301
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302As noted above, the test set is built by going through the items
303from left to right, so this:
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304
305 $ sh ./t9200-git-cvsexport-commit.sh --run='1-4 !3'
306
01e4be6c 307will run tests 1, 2, and 4. Items that come later have higher
2e3a16b2 308precedence. It means that this:
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309
310 $ sh ./t9200-git-cvsexport-commit.sh --run='!3 1-4'
311
312would just run tests from 1 to 4, including 3.
313
314You may use negation with ranges. The following will run all
315test in the test suite except from 7 up to 11:
316
317 $ sh ./t9200-git-cvsexport-commit.sh --run='!7-11'
318
319Some tests in a test suite rely on the previous tests performing
320certain actions, specifically some tests are designated as
321"setup" test, so you cannot _arbitrarily_ disable one test and
322expect the rest to function correctly.
323
324--run is mostly useful when you want to focus on a specific test
325and know what setup is needed for it. Or when you want to run
326everything up to a certain test.
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327
328
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329Running tests with special setups
330---------------------------------
331
332The whole test suite could be run to test some special features
333that cannot be easily covered by a few specific test cases. These
334could be enabled by running the test suite with correct GIT_TEST_
335environment set.
336
c7400399 337GIT_TEST_FAIL_PREREQS=<boolean> fails all prerequisites. This is
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338useful for discovering issues with the tests where say a later test
339implicitly depends on an optional earlier test.
340
341There's a "FAIL_PREREQS" prerequisite that can be used to test for
342whether this mode is active, and e.g. skip some tests that are hard to
343refactor to deal with it. The "SYMLINKS" prerequisite is currently
344excluded as so much relies on it, but this might change in the future.
345
1ff750b1 346GIT_TEST_GETTEXT_POISON=<boolean> turns all strings marked for
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347translation into gibberish if true. Used for spotting those tests that
348need to be marked with a C_LOCALE_OUTPUT prerequisite when adding more
349strings for translation. See "Testing marked strings" in po/README for
350details.
6cdccfce 351
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352GIT_TEST_SPLIT_INDEX=<boolean> forces split-index mode on the whole
353test suite. Accept any boolean values that are accepted by git-config.
354
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355GIT_TEST_PROTOCOL_VERSION=<n>, when set, overrides the
356'protocol.version' setting to n if it is less than n.
357
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358GIT_TEST_FULL_IN_PACK_ARRAY=<boolean> exercises the uncommon
359pack-objects code path where there are more than 1024 packs even if
360the actual number of packs in repository is below this limit. Accept
361any boolean values that are accepted by git-config.
362
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363GIT_TEST_OE_SIZE=<n> exercises the uncommon pack-objects code path
364where we do not cache object size in memory and read it from existing
365packs on demand. This normally only happens when the object size is
366over 2GB. This variable forces the code path on any object larger than
367<n> bytes.
368
ac6e12f9 369GIT_TEST_OE_DELTA_SIZE=<n> exercises the uncommon pack-objects code
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370path where deltas larger than this limit require extra memory
371allocation for bookkeeping.
372
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373GIT_TEST_VALIDATE_INDEX_CACHE_ENTRIES=<boolean> checks that cache-tree
374records are valid when the index is written out or after a merge. This
375is mostly to catch missing invalidation. Default is true.
376
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377GIT_TEST_COMMIT_GRAPH=<boolean>, when true, forces the commit-graph to
378be written after every 'git commit' command, and overrides the
379'core.commitGraph' setting to true.
380
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381GIT_TEST_FSMONITOR=$PWD/t7519/fsmonitor-all exercises the fsmonitor
382code path for utilizing a file system monitor to speed up detecting
383new or changed files.
384
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385GIT_TEST_INDEX_VERSION=<n> exercises the index read/write code path
386for the index version specified. Can be set to any valid version
387(currently 2, 3, or 4).
388
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389GIT_TEST_PACK_SPARSE=<boolean> if enabled will default the pack-objects
390builtin to use the sparse object walk. This can still be overridden by
391the --no-sparse command-line argument.
392
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393GIT_TEST_PRELOAD_INDEX=<boolean> exercises the preload-index code path
394by overriding the minimum number of cache entries required per thread.
395
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396GIT_TEST_STASH_USE_BUILTIN=<boolean>, when false, disables the
397built-in version of git-stash. See 'stash.useBuiltin' in
398git-config(1).
399
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400GIT_TEST_INDEX_THREADS=<n> enables exercising the multi-threaded loading
401of the index for the whole test suite by bypassing the default number of
402cache entries and thread minimums. Setting this to 1 will make the
403index loading single threaded.
404
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405GIT_TEST_MULTI_PACK_INDEX=<boolean>, when true, forces the multi-pack-
406index to be written after every 'git repack' command, and overrides the
407'core.multiPackIndex' setting to true.
408
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409GIT_TEST_SIDEBAND_ALL=<boolean>, when true, overrides the
410'uploadpack.allowSidebandAll' setting to true, and when false, forces
411fetch-pack to not request sideband-all (even if the server advertises
412sideband-all).
413
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414GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS=<boolean>, when true (which is
415the default when running tests), errors out when an abbreviated option
416is used.
417
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418Naming Tests
419------------
420
421The test files are named as:
422
423 tNNNN-commandname-details.sh
424
425where N is a decimal digit.
426
427First digit tells the family:
428
429 0 - the absolute basics and global stuff
430 1 - the basic commands concerning database
431 2 - the basic commands concerning the working tree
432 3 - the other basic commands (e.g. ls-files)
433 4 - the diff commands
434 5 - the pull and exporting commands
435 6 - the revision tree commands (even e.g. merge-base)
8f4a9b62 436 7 - the porcelainish commands concerning the working tree
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437 8 - the porcelainish commands concerning forensics
438 9 - the git tools
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439
440Second digit tells the particular command we are testing.
441
442Third digit (optionally) tells the particular switch or group of switches
443we are testing.
444
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445If you create files under t/ directory (i.e. here) that is not
446the top-level test script, never name the file to match the above
447pattern. The Makefile here considers all such files as the
63d32945 448top-level test script and tries to run all of them. Care is
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449especially needed if you are creating a common test library
450file, similar to test-lib.sh, because such a library file may
451not be suitable for standalone execution.
452
f50c9f76 453
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454Writing Tests
455-------------
456
457The test script is written as a shell script. It should start
51b7a525 458with the standard "#!/bin/sh", and an
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459assignment to variable 'test_description', like this:
460
461 #!/bin/sh
986aa7f1 462
14cd1ff3 463 test_description='xxx test (option --frotz)
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464
465 This test registers the following structure in the cache
466 and tries to run git-ls-files with option --frotz.'
467
f50c9f76 468
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469Source 'test-lib.sh'
470--------------------
471
472After assigning test_description, the test script should source
473test-lib.sh like this:
474
475 . ./test-lib.sh
476
477This test harness library does the following things:
478
479 - If the script is invoked with command line argument --help
480 (or -h), it shows the test_description and exits.
481
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482 - Creates an empty test directory with an empty .git/objects database
483 and chdir(2) into it. This directory is 't/trash
484 directory.$test_name_without_dotsh', with t/ subject to change by
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485 the --root option documented above, and a '.stress-<N>' suffix
486 appended by the --stress option.
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487
488 - Defines standard test helper functions for your scripts to
489 use. These functions are designed to make all scripts behave
490 consistently when command line arguments --verbose (or -v),
491 --debug (or -d), and --immediate (or -i) is given.
492
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493Do's & don'ts
494-------------
20873f45 495
6fd45295 496Here are a few examples of things you probably should and shouldn't do
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497when writing tests.
498
441ee35d 499Here are the "do's:"
20873f45 500
6fd45295 501 - Put all code inside test_expect_success and other assertions.
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502
503 Even code that isn't a test per se, but merely some setup code
6fd45295 504 should be inside a test assertion.
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505
506 - Chain your test assertions
507
508 Write test code like this:
509
510 git merge foo &&
511 git push bar &&
512 test ...
513
514 Instead of:
515
516 git merge hla
517 git push gh
518 test ...
519
520 That way all of the commands in your tests will succeed or fail. If
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521 you must ignore the return value of something, consider using a
522 helper function (e.g. use sane_unset instead of unset, in order
523 to avoid unportable return value for unsetting a variable that was
524 already unset), or prepending the command with test_might_fail or
525 test_must_fail.
20873f45 526
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527 - Check the test coverage for your tests. See the "Test coverage"
528 below.
529
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530 Don't blindly follow test coverage metrics; if a new function you added
531 doesn't have any coverage, then you're probably doing something wrong,
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532 but having 100% coverage doesn't necessarily mean that you tested
533 everything.
534
535 Tests that are likely to smoke out future regressions are better
536 than tests that just inflate the coverage metrics.
537
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538 - When a test checks for an absolute path that a git command generated,
539 construct the expected value using $(pwd) rather than $PWD,
540 $TEST_DIRECTORY, or $TRASH_DIRECTORY. It makes a difference on
541 Windows, where the shell (MSYS bash) mangles absolute path names.
542 For details, see the commit message of 4114156ae9.
543
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544 - Remember that inside the <script> part, the standard output and
545 standard error streams are discarded, and the test harness only
546 reports "ok" or "not ok" to the end user running the tests. Under
547 --verbose, they are shown to help debug the tests.
548
549And here are the "don'ts:"
20873f45 550
441ee35d 551 - Don't exit() within a <script> part.
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552
553 The harness will catch this as a programming error of the test.
554 Use test_done instead if you need to stop the tests early (see
555 "Skipping tests" below).
556
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557 - Don't use '! git cmd' when you want to make sure the git command
558 exits with failure in a controlled way by calling "die()". Instead,
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559 use 'test_must_fail git cmd'. This will signal a failure if git
560 dies in an unexpected way (e.g. segfault).
561
f445500e 562 On the other hand, don't use test_must_fail for running regular
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563 platform commands; just use '! cmd'. We are not in the business
564 of verifying that the world given to us sanely works.
f445500e 565
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566 - Don't feed the output of a git command to a pipe, as in:
567
568 git -C repo ls-files |
569 xargs -n 1 basename |
570 grep foo
571
572 which will discard git's exit code and may mask a crash. In the
573 above example, all exit codes are ignored except grep's.
574
575 Instead, write the output of that command to a temporary
576 file with ">" or assign it to a variable with "x=$(git ...)" rather
577 than pipe it.
578
579 - Don't use command substitution in a way that discards git's exit
580 code. When assigning to a variable, the exit code is not discarded,
581 e.g.:
582
583 x=$(git cat-file -p $sha) &&
584 ...
585
586 is OK because a crash in "git cat-file" will cause the "&&" chain
587 to fail, but:
588
589 test "refs/heads/foo" = "$(git symbolic-ref HEAD)"
590
591 is not OK and a crash in git could go undetected.
592
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593 - Don't use perl without spelling it as "$PERL_PATH". This is to help
594 our friends on Windows where the platform Perl often adds CR before
ad78585e 595 the end of line, and they bundle Git with a version of Perl that
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596 does not do so, whose path is specified with $PERL_PATH. Note that we
597 provide a "perl" function which uses $PERL_PATH under the hood, so
598 you do not need to worry when simply running perl in the test scripts
599 (but you do, for example, on a shebang line or in a sub script
600 created via "write_script").
ad78585e 601
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602 - Don't use sh without spelling it as "$SHELL_PATH", when the script
603 can be misinterpreted by broken platform shell (e.g. Solaris).
ad78585e 604
441ee35d 605 - Don't chdir around in tests. It is not sufficient to chdir to
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606 somewhere and then chdir back to the original location later in
607 the test, as any intermediate step can fail and abort the test,
608 causing the next test to start in an unexpected directory. Do so
609 inside a subshell if necessary.
610
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611 - Don't save and verify the standard error of compound commands, i.e.
612 group commands, subshells, and shell functions (except test helper
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613 functions like 'test_must_fail') like this:
614
615 ( cd dir && git cmd ) 2>error &&
616 test_cmp expect error
617
618 When running the test with '-x' tracing, then the trace of commands
619 executed in the compound command will be included in standard error
620 as well, quite possibly throwing off the subsequent checks examining
621 the output. Instead, save only the relevant git command's standard
622 error:
623
624 ( cd dir && git cmd 2>../error ) &&
625 test_cmp expect error
626
441ee35d 627 - Don't break the TAP output
20873f45 628
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629 The raw output from your test may be interpreted by a TAP harness. TAP
630 harnesses will ignore everything they don't know about, but don't step
631 on their toes in these areas:
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632
633 - Don't print lines like "$x..$y" where $x and $y are integers.
634
635 - Don't print lines that begin with "ok" or "not ok".
636
6fd45295 637 TAP harnesses expect a line that begins with either "ok" and "not
20873f45
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638 ok" to signal a test passed or failed (and our harness already
639 produces such lines), so your script shouldn't emit such lines to
640 their output.
641
642 You can glean some further possible issues from the TAP grammar
c1d44cee 643 (see https://metacpan.org/pod/TAP::Parser::Grammar#TAP-GRAMMAR)
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644 but the best indication is to just run the tests with prove(1),
645 it'll complain if anything is amiss.
646
20873f45 647
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648Skipping tests
649--------------
650
681186ae 651If you need to skip tests you should do so by using the three-arg form
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652of the test_* functions (see the "Test harness library" section
653below), e.g.:
654
ad78585e 655 test_expect_success PERL 'I need Perl' '
a0e0ec9f 656 perl -e "hlagh() if unf_unf()"
ad78585e 657 '
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658
659The advantage of skipping tests like this is that platforms that don't
660have the PERL and other optional dependencies get an indication of how
661many tests they're missing.
662
663If the test code is too hairy for that (i.e. does a lot of setup work
664outside test assertions) you can also skip all remaining tests by
665setting skip_all and immediately call test_done:
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666
667 if ! test_have_prereq PERL
668 then
669 skip_all='skipping perl interface tests, perl not available'
670 test_done
671 fi
14cd1ff3 672
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673The string you give to skip_all will be used as an explanation for why
674the test was skipped.
675
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676End with test_done
677------------------
678
679Your script will be a sequence of tests, using helper functions
680from the test harness library. At the end of the script, call
681'test_done'.
682
683
684Test harness library
685--------------------
686
687There are a handful helper functions defined in the test harness
688library for your script to use.
689
9a897893 690 - test_expect_success [<prereq>] <message> <script>
986aa7f1 691
72942a61 692 Usually takes two strings as parameters, and evaluates the
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693 <script>. If it yields success, test is considered
694 successful. <message> should state what it is testing.
695
696 Example:
697
698 test_expect_success \
699 'git-write-tree should be able to write an empty tree.' \
700 'tree=$(git-write-tree)'
701
9a897893 702 If you supply three parameters the first will be taken to be a
72942a61 703 prerequisite; see the test_set_prereq and test_have_prereq
9a897893
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704 documentation below:
705
706 test_expect_success TTY 'git --paginate rev-list uses a pager' \
707 ' ... '
708
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709 You can also supply a comma-separated list of prerequisites, in the
710 rare case where your test depends on more than one:
711
712 test_expect_success PERL,PYTHON 'yo dawg' \
713 ' test $(perl -E 'print eval "1 +" . qx[python -c "print 2"]') == "4" '
714
9a897893 715 - test_expect_failure [<prereq>] <message> <script>
986aa7f1 716
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717 This is NOT the opposite of test_expect_success, but is used
718 to mark a test that demonstrates a known breakage. Unlike
719 the usual test_expect_success tests, which say "ok" on
720 success and "FAIL" on failure, this will say "FIXED" on
721 success and "still broken" on failure. Failures from these
722 tests won't cause -i (immediate) to stop.
986aa7f1 723
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724 Like test_expect_success this function can optionally use a three
725 argument invocation with a prerequisite as the first argument.
726
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727 - test_debug <script>
728
729 This takes a single argument, <script>, and evaluates it only
730 when the test script is started with --debug command line
731 argument. This is primarily meant for use during the
732 development of a new test script.
733
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734 - debug <git-command>
735
736 Run a git command inside a debugger. This is primarily meant for
737 use when debugging a failing test script.
738
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739 - test_done
740
741 Your test script must have test_done at the end. Its purpose
742 is to summarize successes and failures in the test script and
743 exit with an appropriate error code.
744
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745 - test_tick
746
747 Make commit and tag names consistent by setting the author and
63d32945 748 committer times to defined state. Subsequent calls will
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749 advance the times by a fixed amount.
750
751 - test_commit <message> [<filename> [<contents>]]
752
753 Creates a commit with the given message, committing the given
754 file with the given contents (default for both is to reuse the
755 message string), and adds a tag (again reusing the message
756 string as name). Calls test_tick to make the SHA-1s
757 reproducible.
758
759 - test_merge <message> <commit-or-tag>
760
761 Merges the given rev using the given message. Like test_commit,
762 creates a tag and calls test_tick before committing.
986aa7f1 763
72942a61 764 - test_set_prereq <prereq>
9a897893
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765
766 Set a test prerequisite to be used later with test_have_prereq. The
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767 test-lib will set some prerequisites for you, see the
768 "Prerequisites" section below for a full list of these.
769
770 Others you can set yourself and use later with either
771 test_have_prereq directly, or the three argument invocation of
772 test_expect_success and test_expect_failure.
9a897893 773
72942a61 774 - test_have_prereq <prereq>
9a897893 775
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ÆAB
776 Check if we have a prerequisite previously set with test_set_prereq.
777 The most common way to use this explicitly (as opposed to the
778 implicit use when an argument is passed to test_expect_*) is to skip
779 all the tests at the start of the test script if we don't have some
780 essential prerequisite:
9a897893
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781
782 if ! test_have_prereq PERL
783 then
784 skip_all='skipping perl interface tests, perl not available'
785 test_done
786 fi
787
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788 - test_external [<prereq>] <message> <external> <script>
789
790 Execute a <script> with an <external> interpreter (like perl). This
791 was added for tests like t9700-perl-git.sh which do most of their
792 work in an external test script.
793
794 test_external \
795 'GitwebCache::*FileCache*' \
a0e0ec9f 796 perl "$TEST_DIRECTORY"/t9503/test_cache_interface.pl
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797
798 If the test is outputting its own TAP you should set the
799 test_external_has_tap variable somewhere before calling the first
800 test_external* function. See t9700-perl-git.sh for an example.
801
802 # The external test will outputs its own plan
803 test_external_has_tap=1
804
805 - test_external_without_stderr [<prereq>] <message> <external> <script>
806
807 Like test_external but fail if there's any output on stderr,
808 instead of checking the exit code.
809
810 test_external_without_stderr \
811 'Perl API' \
a0e0ec9f 812 perl "$TEST_DIRECTORY"/t9700/test.pl
2fac6a4b 813
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814 - test_expect_code <exit-code> <command>
815
816 Run a command and ensure that it exits with the given exit code.
817 For example:
818
819 test_expect_success 'Merge with d/f conflicts' '
820 test_expect_code 1 git merge "merge msg" B master
821 '
822
12e31a6b 823 - test_must_fail [<options>] <git-command>
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824
825 Run a git command and ensure it fails in a controlled way. Use
971ecbd1
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826 this instead of "! <git-command>". When git-command dies due to a
827 segfault, test_must_fail diagnoses it as an error; "! <git-command>"
828 treats it as just another expected failure, which would let such a
829 bug go unnoticed.
c9667456 830
12e31a6b
SG
831 Accepts the following options:
832
833 ok=<signal-name>[,<...>]:
834 Don't treat an exit caused by the given signal as error.
835 Multiple signals can be specified as a comma separated list.
836 Currently recognized signal names are: sigpipe, success.
837 (Don't use 'success', use 'test_might_fail' instead.)
838
839 - test_might_fail [<options>] <git-command>
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840
841 Similar to test_must_fail, but tolerate success, too. Use this
842 instead of "<git-command> || :" to catch failures due to segv.
843
12e31a6b
SG
844 Accepts the same options as test_must_fail.
845
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846 - test_cmp <expected> <actual>
847
848 Check whether the content of the <actual> file matches the
849 <expected> file. This behaves like "cmp" but produces more
850 helpful output when the test is run with "-v" option.
851
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TG
852 - test_cmp_rev <expected> <actual>
853
854 Check whether the <expected> rev points to the same commit as the
855 <actual> rev.
856
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857 - test_line_count (= | -lt | -ge | ...) <length> <file>
858
859 Check whether a file has the length it is expected to.
860
72942a61
ML
861 - test_path_is_file <path> [<diagnosis>]
862 test_path_is_dir <path> [<diagnosis>]
2caf20c5
MM
863 test_path_is_missing <path> [<diagnosis>]
864
72942a61
ML
865 Check if the named path is a file, if the named path is a
866 directory, or if the named path does not exist, respectively,
867 and fail otherwise, showing the <diagnosis> text.
2caf20c5 868
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869 - test_when_finished <script>
870
871 Prepend <script> to a list of commands to run to clean up
872 at the end of the current test. If some clean-up command
873 fails, the test will not pass.
874
875 Example:
876
877 test_expect_success 'branch pointing to non-commit' '
878 git rev-parse HEAD^{tree} >.git/refs/heads/invalid &&
879 test_when_finished "git update-ref -d refs/heads/invalid" &&
880 ...
881 '
882
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JS
883 - test_atexit <script>
884
885 Prepend <script> to a list of commands to run unconditionally to
886 clean up before the test script exits, e.g. to stop a daemon:
887
888 test_expect_success 'test git daemon' '
889 git daemon &
890 daemon_pid=$! &&
891 test_atexit 'kill $daemon_pid' &&
892 hello world
893 '
894
895 The commands will be executed before the trash directory is removed,
896 i.e. the atexit commands will still be able to access any pidfiles or
897 socket files.
898
899 Note that these commands will be run even when a test script run
900 with '--immediate' fails. Be careful with your atexit commands to
901 minimize any changes to the failed state.
902
bb98b01e 903 - test_write_lines <lines>
ac9afcc3 904
bb98b01e 905 Write <lines> on standard output, one line per argument.
ac9afcc3
MT
906 Useful to prepare multi-line files in a compact form.
907
908 Example:
909
bb98b01e 910 test_write_lines a b c d e f g >foo
ac9afcc3
MT
911
912 Is a more compact equivalent of:
913 cat >foo <<-EOF
914 a
915 b
916 c
917 d
918 e
919 f
920 g
921 EOF
922
923
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924 - test_pause
925
926 This command is useful for writing and debugging tests and must be
927 removed before submitting. It halts the execution of the test and
928 spawns a shell in the trash directory. Exit the shell to continue
929 the test. Example:
930
931 test_expect_success 'test' '
932 git do-something >actual &&
933 test_pause &&
934 test_cmp expected actual
935 '
936
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JS
937 - test_ln_s_add <path1> <path2>
938
939 This function helps systems whose filesystem does not support symbolic
940 links. Use it to add a symbolic link entry to the index when it is not
941 important that the file system entry is a symbolic link, i.e., instead
942 of the sequence
943
944 ln -s foo bar &&
945 git add bar
946
947 Sometimes it is possible to split a test in a part that does not need
948 the symbolic link in the file system and a part that does; then only
949 the latter part need be protected by a SYMLINKS prerequisite (see below).
950
2c02b110 951 - test_oid_init
952
953 This function loads facts and useful object IDs related to the hash
954 algorithm(s) in use from the files in t/oid-info.
955
956 - test_oid_cache
957
958 This function reads per-hash algorithm information from standard
959 input (usually a heredoc) in the format described in
960 t/oid-info/README. This is useful for test-specific values, such as
961 object IDs, which must vary based on the hash algorithm.
962
963 Certain fixed values, such as hash sizes and common placeholder
964 object IDs, can be loaded with test_oid_init (described above).
965
966 - test_oid <key>
967
968 This function looks up a value for the hash algorithm in use, based
969 on the key given. The value must have been loaded using
970 test_oid_init or test_oid_cache. Providing an unknown key is an
971 error.
972
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973 - yes [<string>]
974
975 This is often seen in modern UNIX but some platforms lack it, so
976 the test harness overrides the platform implementation with a
977 more limited one. Use this only when feeding a handful lines of
978 output to the downstream---unlike the real version, it generates
979 only up to 99 lines.
980
981
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982Prerequisites
983-------------
984
985These are the prerequisites that the test library predefines with
986test_have_prereq.
987
988See the prereq argument to the test_* functions in the "Test harness
989library" section above and the "test_have_prereq" function for how to
990use these, and "test_set_prereq" for how to define your own.
991
f8fc0ee3 992 - PYTHON
be53deef 993
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994 Git wasn't compiled with NO_PYTHON=YesPlease. Wrap any tests that
995 need Python with this.
996
997 - PERL
998
999 Git wasn't compiled with NO_PERL=YesPlease.
1000
1001 Even without the PERL prerequisite, tests can assume there is a
1002 usable perl interpreter at $PERL_PATH, though it need not be
1003 particularly modern.
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1004
1005 - POSIXPERM
1006
1007 The filesystem supports POSIX style permission bits.
1008
1009 - BSLASHPSPEC
1010
1011 Backslashes in pathspec are not directory separators. This is not
1012 set on Windows. See 6fd1106a for details.
1013
1014 - EXECKEEPSPID
1015
1016 The process retains the same pid across exec(2). See fb9a2bea for
1017 details.
1018
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1019 - PIPE
1020
1021 The filesystem we're on supports creation of FIFOs (named pipes)
1022 via mkfifo(1).
1023
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1024 - SYMLINKS
1025
1026 The filesystem we're on supports symbolic links. E.g. a FAT
1027 filesystem doesn't support these. See 704a3143 for details.
2fac6a4b 1028
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ÆAB
1029 - SANITY
1030
1031 Test is not run by root user, and an attempt to write to an
1032 unwritable file is expected to fail correctly.
2fac6a4b 1033
3eb585c1 1034 - PCRE
8f852ce6 1035
3eb585c1 1036 Git was compiled with support for PCRE. Wrap any tests
8f852ce6
MK
1037 that use git-grep --perl-regexp or git-grep -P in these.
1038
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ÆAB
1039 - LIBPCRE1
1040
1041 Git was compiled with PCRE v1 support via
1042 USE_LIBPCRE1=YesPlease. Wrap any PCRE using tests that for some
1043 reason need v1 of the PCRE library instead of v2 in these.
1044
1045 - LIBPCRE2
1046
1047 Git was compiled with PCRE v2 support via
1048 USE_LIBPCRE2=YesPlease. Wrap any PCRE using tests that for some
1049 reason need v2 of the PCRE library instead of v1 in these.
1050
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1051 - CASE_INSENSITIVE_FS
1052
1053 Test is run on a case insensitive file system.
1054
5b0b5dd4
MG
1055 - UTF8_NFD_TO_NFC
1056
1057 Test is run on a filesystem which converts decomposed utf-8 (nfd)
1058 to precomposed utf-8 (nfc).
1059
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1060 - PTHREADS
1061
1062 Git wasn't compiled with NO_PTHREADS=YesPlease.
1063
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1064Tips for Writing Tests
1065----------------------
1066
1067As with any programming projects, existing programs are the best
1068source of the information. However, do _not_ emulate
1069t0000-basic.sh when writing your tests. The test is special in
1070that it tries to validate the very core of GIT. For example, it
1071knows that there will be 256 subdirectories under .git/objects/,
1072and it knows that the object ID of an empty tree is a certain
107340-byte string. This is deliberately done so in t0000-basic.sh
1074because the things the very basic core test tries to achieve is
1075to serve as a basis for people who are changing the GIT internal
1076drastically. For these people, after making certain changes,
1077not seeing failures from the basic test _is_ a failure. And
1078such drastic changes to the core GIT that even changes these
1079otherwise supposedly stable object IDs should be accompanied by
1080an update to t0000-basic.sh.
1081
1082However, other tests that simply rely on basic parts of the core
1083GIT working properly should not have that level of intimate
1084knowledge of the core GIT internals. If all the test scripts
1085hardcoded the object IDs like t0000-basic.sh does, that defeats
1086the purpose of t0000-basic.sh, which is to isolate that level of
1087validation in one place. Your test also ends up needing
1088updating when such a change to the internal happens, so do _not_
1089do it and leave the low level of validation to t0000-basic.sh.
d15e9ebc 1090
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ÆAB
1091Test coverage
1092-------------
1093
1094You can use the coverage tests to find code paths that are not being
1095used or properly exercised yet.
1096
1097To do that, run the coverage target at the top-level (not in the t/
1098directory):
1099
1100 make coverage
1101
1102That'll compile Git with GCC's coverage arguments, and generate a test
1103report with gcov after the tests finish. Running the coverage tests
1104can take a while, since running the tests in parallel is incompatible
1105with GCC's coverage mode.
1106
1107After the tests have run you can generate a list of untested
1108functions:
1109
1110 make coverage-untested-functions
1111
1112You can also generate a detailed per-file HTML report using the
1113Devel::Cover module. To install it do:
1114
1115 # On Debian or Ubuntu:
1116 sudo aptitude install libdevel-cover-perl
1117
1118 # From the CPAN with cpanminus
1119 curl -L http://cpanmin.us | perl - --sudo --self-upgrade
1120 cpanm --sudo Devel::Cover
1121
1122Then, at the top-level:
1123
1124 make cover_db_html
1125
1126That'll generate a detailed cover report in the "cover_db_html"
1127directory, which you can then copy to a webserver, or inspect locally
1128in a browser.