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[git/git.git] / t / README
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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 ***
5c94f87e 21 * ok 1: .git/objects should be empty after git-init in an empty repo.
986aa7f1 22 * ok 2: .git/objects should have 256 subdirectories.
215a7ad1 23 * ok 3: git-update-index without --add should fail adding.
986aa7f1 24 ...
215a7ad1 25 * ok 23: no diff after checkout and git-update-index --refresh.
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26 * passed all 23 test(s)
27 *** t0100-environment-names.sh ***
28 * ok 1: using old names should issue warnings.
29 * ok 2: using old names but having new names should not issue warnings.
30 ...
31
32Or you can run each test individually from command line, like
33this:
34
14cd1ff3 35 $ sh ./t3001-ls-files-killed.sh
215a7ad1 36 * ok 1: git-update-index --add to add various paths.
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37 * ok 2: git-ls-files -k to show killed files.
38 * ok 3: validate git-ls-files -k output.
39 * passed all 3 test(s)
40
41You can pass --verbose (or -v), --debug (or -d), and --immediate
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42(or -i) command line argument to the test, or by setting GIT_TEST_OPTS
43appropriately before running "make".
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44
45--verbose::
46 This makes the test more verbose. Specifically, the
47 command being run and their output if any are also
48 output.
49
50--debug::
51 This may help the person who is developing a new test.
52 It causes the command defined with test_debug to run.
53
54--immediate::
55 This causes the test to immediately exit upon the first
56 failed test.
57
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58--long-tests::
59 This causes additional long-running tests to be run (where
60 available), for more exhaustive testing.
61
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62--valgrind::
63 Execute all Git binaries with valgrind and exit with status
64 126 on errors (just like regular tests, this will only stop
65 the test script when running under -i). Valgrind errors
66 go to stderr, so you might want to pass the -v option, too.
986aa7f1 67
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68 Since it makes no sense to run the tests with --valgrind and
69 not see any output, this option implies --verbose. For
70 convenience, it also implies --tee.
71
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72--tee::
73 In addition to printing the test output to the terminal,
74 write it to files named 't/test-results/$TEST_NAME.out'.
75 As the names depend on the tests' file names, it is safe to
76 run the tests with this option in parallel.
77
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78--with-dashes::
79 By default tests are run without dashed forms of
80 commands (like git-commit) in the PATH (it only uses
81 wrappers from ../bin-wrappers). Use this option to include
82 the build directory (..) in the PATH, which contains all
83 the dashed forms of commands. This option is currently
84 implied by other options like --valgrind and
85 GIT_TEST_INSTALLED.
86
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87--root=<directory>::
88 Create "trash" directories used to store all temporary data during
89 testing under <directory>, instead of the t/ directory.
90 Using this option with a RAM-based filesystem (such as tmpfs)
91 can massively speed up the test suite.
92
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93You can also set the GIT_TEST_INSTALLED environment variable to
94the bindir of an existing git installation to test that installation.
95You still need to have built this git sandbox, from which various
96test-* support programs, templates, and perl libraries are used.
97If your installed git is incomplete, it will silently test parts of
98your built version instead.
99
100When using GIT_TEST_INSTALLED, you can also set GIT_TEST_EXEC_PATH to
101override the location of the dashed-form subcommands (what
102GIT_EXEC_PATH would be used for during normal operation).
103GIT_TEST_EXEC_PATH defaults to `$GIT_TEST_INSTALLED/git --exec-path`.
104
105
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106Skipping Tests
107--------------
108
109In some environments, certain tests have no way of succeeding
110due to platform limitation, such as lack of 'unzip' program, or
111filesystem that do not allow arbitrary sequence of non-NUL bytes
112as pathnames.
113
114You should be able to say something like
115
116 $ GIT_SKIP_TESTS=t9200.8 sh ./t9200-git-cvsexport-commit.sh
117
118and even:
119
120 $ GIT_SKIP_TESTS='t[0-4]??? t91?? t9200.8' make
121
122to omit such tests. The value of the environment variable is a
123SP separated list of patterns that tells which tests to skip,
124and either can match the "t[0-9]{4}" part to skip the whole
125test, or t[0-9]{4} followed by ".$number" to say which
126particular test to skip.
127
128Note that some tests in the existing test suite rely on previous
129test item, so you cannot arbitrarily disable one and expect the
130remainder of test to check what the test originally was intended
131to check.
132
133
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134Naming Tests
135------------
136
137The test files are named as:
138
139 tNNNN-commandname-details.sh
140
141where N is a decimal digit.
142
143First digit tells the family:
144
145 0 - the absolute basics and global stuff
146 1 - the basic commands concerning database
147 2 - the basic commands concerning the working tree
148 3 - the other basic commands (e.g. ls-files)
149 4 - the diff commands
150 5 - the pull and exporting commands
151 6 - the revision tree commands (even e.g. merge-base)
8f4a9b62 152 7 - the porcelainish commands concerning the working tree
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153 8 - the porcelainish commands concerning forensics
154 9 - the git tools
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155
156Second digit tells the particular command we are testing.
157
158Third digit (optionally) tells the particular switch or group of switches
159we are testing.
160
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161If you create files under t/ directory (i.e. here) that is not
162the top-level test script, never name the file to match the above
163pattern. The Makefile here considers all such files as the
164top-level test script and tries to run all of them. A care is
165especially needed if you are creating a common test library
166file, similar to test-lib.sh, because such a library file may
167not be suitable for standalone execution.
168
f50c9f76 169
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170Writing Tests
171-------------
172
173The test script is written as a shell script. It should start
174with the standard "#!/bin/sh" with copyright notices, and an
175assignment to variable 'test_description', like this:
176
177 #!/bin/sh
178 #
179 # Copyright (c) 2005 Junio C Hamano
180 #
181
14cd1ff3 182 test_description='xxx test (option --frotz)
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183
184 This test registers the following structure in the cache
185 and tries to run git-ls-files with option --frotz.'
186
f50c9f76 187
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188Source 'test-lib.sh'
189--------------------
190
191After assigning test_description, the test script should source
192test-lib.sh like this:
193
194 . ./test-lib.sh
195
196This test harness library does the following things:
197
198 - If the script is invoked with command line argument --help
199 (or -h), it shows the test_description and exits.
200
201 - Creates an empty test directory with an empty .git/objects
9231e3a9 202 database and chdir(2) into it. This directory is 't/trash directory'
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203 if you must know, but I do not think you care.
204
205 - Defines standard test helper functions for your scripts to
206 use. These functions are designed to make all scripts behave
207 consistently when command line arguments --verbose (or -v),
208 --debug (or -d), and --immediate (or -i) is given.
209
14cd1ff3 210
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211End with test_done
212------------------
213
214Your script will be a sequence of tests, using helper functions
215from the test harness library. At the end of the script, call
216'test_done'.
217
218
219Test harness library
220--------------------
221
222There are a handful helper functions defined in the test harness
223library for your script to use.
224
225 - test_expect_success <message> <script>
226
227 This takes two strings as parameter, and evaluates the
228 <script>. If it yields success, test is considered
229 successful. <message> should state what it is testing.
230
231 Example:
232
233 test_expect_success \
234 'git-write-tree should be able to write an empty tree.' \
235 'tree=$(git-write-tree)'
236
237 - test_expect_failure <message> <script>
238
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239 This is NOT the opposite of test_expect_success, but is used
240 to mark a test that demonstrates a known breakage. Unlike
241 the usual test_expect_success tests, which say "ok" on
242 success and "FAIL" on failure, this will say "FIXED" on
243 success and "still broken" on failure. Failures from these
244 tests won't cause -i (immediate) to stop.
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245
246 - test_debug <script>
247
248 This takes a single argument, <script>, and evaluates it only
249 when the test script is started with --debug command line
250 argument. This is primarily meant for use during the
251 development of a new test script.
252
253 - test_done
254
255 Your test script must have test_done at the end. Its purpose
256 is to summarize successes and failures in the test script and
257 exit with an appropriate error code.
258
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259 - test_tick
260
261 Make commit and tag names consistent by setting the author and
262 committer times to defined stated. Subsequent calls will
263 advance the times by a fixed amount.
264
265 - test_commit <message> [<filename> [<contents>]]
266
267 Creates a commit with the given message, committing the given
268 file with the given contents (default for both is to reuse the
269 message string), and adds a tag (again reusing the message
270 string as name). Calls test_tick to make the SHA-1s
271 reproducible.
272
273 - test_merge <message> <commit-or-tag>
274
275 Merges the given rev using the given message. Like test_commit,
276 creates a tag and calls test_tick before committing.
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277
278Tips for Writing Tests
279----------------------
280
281As with any programming projects, existing programs are the best
282source of the information. However, do _not_ emulate
283t0000-basic.sh when writing your tests. The test is special in
284that it tries to validate the very core of GIT. For example, it
285knows that there will be 256 subdirectories under .git/objects/,
286and it knows that the object ID of an empty tree is a certain
28740-byte string. This is deliberately done so in t0000-basic.sh
288because the things the very basic core test tries to achieve is
289to serve as a basis for people who are changing the GIT internal
290drastically. For these people, after making certain changes,
291not seeing failures from the basic test _is_ a failure. And
292such drastic changes to the core GIT that even changes these
293otherwise supposedly stable object IDs should be accompanied by
294an update to t0000-basic.sh.
295
296However, other tests that simply rely on basic parts of the core
297GIT working properly should not have that level of intimate
298knowledge of the core GIT internals. If all the test scripts
299hardcoded the object IDs like t0000-basic.sh does, that defeats
300the purpose of t0000-basic.sh, which is to isolate that level of
301validation in one place. Your test also ends up needing
302updating when such a change to the internal happens, so do _not_
303do it and leave the low level of validation to t0000-basic.sh.