Valgrind support: check for more than just programming errors
[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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68Skipping Tests
69--------------
70
71In some environments, certain tests have no way of succeeding
72due to platform limitation, such as lack of 'unzip' program, or
73filesystem that do not allow arbitrary sequence of non-NUL bytes
74as pathnames.
75
76You should be able to say something like
77
78 $ GIT_SKIP_TESTS=t9200.8 sh ./t9200-git-cvsexport-commit.sh
79
80and even:
81
82 $ GIT_SKIP_TESTS='t[0-4]??? t91?? t9200.8' make
83
84to omit such tests. The value of the environment variable is a
85SP separated list of patterns that tells which tests to skip,
86and either can match the "t[0-9]{4}" part to skip the whole
87test, or t[0-9]{4} followed by ".$number" to say which
88particular test to skip.
89
90Note that some tests in the existing test suite rely on previous
91test item, so you cannot arbitrarily disable one and expect the
92remainder of test to check what the test originally was intended
93to check.
94
95
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96Naming Tests
97------------
98
99The test files are named as:
100
101 tNNNN-commandname-details.sh
102
103where N is a decimal digit.
104
105First digit tells the family:
106
107 0 - the absolute basics and global stuff
108 1 - the basic commands concerning database
109 2 - the basic commands concerning the working tree
110 3 - the other basic commands (e.g. ls-files)
111 4 - the diff commands
112 5 - the pull and exporting commands
113 6 - the revision tree commands (even e.g. merge-base)
8f4a9b62 114 7 - the porcelainish commands concerning the working tree
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115 8 - the porcelainish commands concerning forensics
116 9 - the git tools
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117
118Second digit tells the particular command we are testing.
119
120Third digit (optionally) tells the particular switch or group of switches
121we are testing.
122
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123If you create files under t/ directory (i.e. here) that is not
124the top-level test script, never name the file to match the above
125pattern. The Makefile here considers all such files as the
126top-level test script and tries to run all of them. A care is
127especially needed if you are creating a common test library
128file, similar to test-lib.sh, because such a library file may
129not be suitable for standalone execution.
130
f50c9f76 131
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132Writing Tests
133-------------
134
135The test script is written as a shell script. It should start
136with the standard "#!/bin/sh" with copyright notices, and an
137assignment to variable 'test_description', like this:
138
139 #!/bin/sh
140 #
141 # Copyright (c) 2005 Junio C Hamano
142 #
143
14cd1ff3 144 test_description='xxx test (option --frotz)
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145
146 This test registers the following structure in the cache
147 and tries to run git-ls-files with option --frotz.'
148
f50c9f76 149
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150Source 'test-lib.sh'
151--------------------
152
153After assigning test_description, the test script should source
154test-lib.sh like this:
155
156 . ./test-lib.sh
157
158This test harness library does the following things:
159
160 - If the script is invoked with command line argument --help
161 (or -h), it shows the test_description and exits.
162
163 - Creates an empty test directory with an empty .git/objects
9231e3a9 164 database and chdir(2) into it. This directory is 't/trash directory'
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165 if you must know, but I do not think you care.
166
167 - Defines standard test helper functions for your scripts to
168 use. These functions are designed to make all scripts behave
169 consistently when command line arguments --verbose (or -v),
170 --debug (or -d), and --immediate (or -i) is given.
171
14cd1ff3 172
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173End with test_done
174------------------
175
176Your script will be a sequence of tests, using helper functions
177from the test harness library. At the end of the script, call
178'test_done'.
179
180
181Test harness library
182--------------------
183
184There are a handful helper functions defined in the test harness
185library for your script to use.
186
187 - test_expect_success <message> <script>
188
189 This takes two strings as parameter, and evaluates the
190 <script>. If it yields success, test is considered
191 successful. <message> should state what it is testing.
192
193 Example:
194
195 test_expect_success \
196 'git-write-tree should be able to write an empty tree.' \
197 'tree=$(git-write-tree)'
198
199 - test_expect_failure <message> <script>
200
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201 This is NOT the opposite of test_expect_success, but is used
202 to mark a test that demonstrates a known breakage. Unlike
203 the usual test_expect_success tests, which say "ok" on
204 success and "FAIL" on failure, this will say "FIXED" on
205 success and "still broken" on failure. Failures from these
206 tests won't cause -i (immediate) to stop.
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207
208 - test_debug <script>
209
210 This takes a single argument, <script>, and evaluates it only
211 when the test script is started with --debug command line
212 argument. This is primarily meant for use during the
213 development of a new test script.
214
215 - test_done
216
217 Your test script must have test_done at the end. Its purpose
218 is to summarize successes and failures in the test script and
219 exit with an appropriate error code.
220
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221 - test_tick
222
223 Make commit and tag names consistent by setting the author and
224 committer times to defined stated. Subsequent calls will
225 advance the times by a fixed amount.
226
227 - test_commit <message> [<filename> [<contents>]]
228
229 Creates a commit with the given message, committing the given
230 file with the given contents (default for both is to reuse the
231 message string), and adds a tag (again reusing the message
232 string as name). Calls test_tick to make the SHA-1s
233 reproducible.
234
235 - test_merge <message> <commit-or-tag>
236
237 Merges the given rev using the given message. Like test_commit,
238 creates a tag and calls test_tick before committing.
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239
240Tips for Writing Tests
241----------------------
242
243As with any programming projects, existing programs are the best
244source of the information. However, do _not_ emulate
245t0000-basic.sh when writing your tests. The test is special in
246that it tries to validate the very core of GIT. For example, it
247knows that there will be 256 subdirectories under .git/objects/,
248and it knows that the object ID of an empty tree is a certain
24940-byte string. This is deliberately done so in t0000-basic.sh
250because the things the very basic core test tries to achieve is
251to serve as a basis for people who are changing the GIT internal
252drastically. For these people, after making certain changes,
253not seeing failures from the basic test _is_ a failure. And
254such drastic changes to the core GIT that even changes these
255otherwise supposedly stable object IDs should be accompanied by
256an update to t0000-basic.sh.
257
258However, other tests that simply rely on basic parts of the core
259GIT working properly should not have that level of intimate
260knowledge of the core GIT internals. If all the test scripts
261hardcoded the object IDs like t0000-basic.sh does, that defeats
262the purpose of t0000-basic.sh, which is to isolate that level of
263validation in one place. Your test also ends up needing
264updating when such a change to the internal happens, so do _not_
265do it and leave the low level of validation to t0000-basic.sh.