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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
42(or -i) command line argument to the test.
43
44--verbose::
45 This makes the test more verbose. Specifically, the
46 command being run and their output if any are also
47 output.
48
49--debug::
50 This may help the person who is developing a new test.
51 It causes the command defined with test_debug to run.
52
53--immediate::
54 This causes the test to immediately exit upon the first
55 failed test.
56
57
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58Naming Tests
59------------
60
61The test files are named as:
62
63 tNNNN-commandname-details.sh
64
65where N is a decimal digit.
66
67First digit tells the family:
68
69 0 - the absolute basics and global stuff
70 1 - the basic commands concerning database
71 2 - the basic commands concerning the working tree
72 3 - the other basic commands (e.g. ls-files)
73 4 - the diff commands
74 5 - the pull and exporting commands
75 6 - the revision tree commands (even e.g. merge-base)
8f4a9b62 76 7 - the porcelainish commands concerning the working tree
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77 8 - the porcelainish commands concerning forensics
78 9 - the git tools
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79
80Second digit tells the particular command we are testing.
81
82Third digit (optionally) tells the particular switch or group of switches
83we are testing.
84
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85If you create files under t/ directory (i.e. here) that is not
86the top-level test script, never name the file to match the above
87pattern. The Makefile here considers all such files as the
88top-level test script and tries to run all of them. A care is
89especially needed if you are creating a common test library
90file, similar to test-lib.sh, because such a library file may
91not be suitable for standalone execution.
92
f50c9f76 93
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94Writing Tests
95-------------
96
97The test script is written as a shell script. It should start
98with the standard "#!/bin/sh" with copyright notices, and an
99assignment to variable 'test_description', like this:
100
101 #!/bin/sh
102 #
103 # Copyright (c) 2005 Junio C Hamano
104 #
105
14cd1ff3 106 test_description='xxx test (option --frotz)
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107
108 This test registers the following structure in the cache
109 and tries to run git-ls-files with option --frotz.'
110
f50c9f76 111
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112Source 'test-lib.sh'
113--------------------
114
115After assigning test_description, the test script should source
116test-lib.sh like this:
117
118 . ./test-lib.sh
119
120This test harness library does the following things:
121
122 - If the script is invoked with command line argument --help
123 (or -h), it shows the test_description and exits.
124
125 - Creates an empty test directory with an empty .git/objects
126 database and chdir(2) into it. This directory is 't/trash'
127 if you must know, but I do not think you care.
128
129 - Defines standard test helper functions for your scripts to
130 use. These functions are designed to make all scripts behave
131 consistently when command line arguments --verbose (or -v),
132 --debug (or -d), and --immediate (or -i) is given.
133
14cd1ff3 134
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135End with test_done
136------------------
137
138Your script will be a sequence of tests, using helper functions
139from the test harness library. At the end of the script, call
140'test_done'.
141
142
143Test harness library
144--------------------
145
146There are a handful helper functions defined in the test harness
147library for your script to use.
148
149 - test_expect_success <message> <script>
150
151 This takes two strings as parameter, and evaluates the
152 <script>. If it yields success, test is considered
153 successful. <message> should state what it is testing.
154
155 Example:
156
157 test_expect_success \
158 'git-write-tree should be able to write an empty tree.' \
159 'tree=$(git-write-tree)'
160
161 - test_expect_failure <message> <script>
162
163 This is the opposite of test_expect_success. If <script>
164 yields success, test is considered a failure.
165
166 Example:
167
168 test_expect_failure \
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169 'git-update-index without --add should fail adding.' \
170 'git-update-index should-be-empty'
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171
172 - test_debug <script>
173
174 This takes a single argument, <script>, and evaluates it only
175 when the test script is started with --debug command line
176 argument. This is primarily meant for use during the
177 development of a new test script.
178
179 - test_done
180
181 Your test script must have test_done at the end. Its purpose
182 is to summarize successes and failures in the test script and
183 exit with an appropriate error code.
184
185
186Tips for Writing Tests
187----------------------
188
189As with any programming projects, existing programs are the best
190source of the information. However, do _not_ emulate
191t0000-basic.sh when writing your tests. The test is special in
192that it tries to validate the very core of GIT. For example, it
193knows that there will be 256 subdirectories under .git/objects/,
194and it knows that the object ID of an empty tree is a certain
19540-byte string. This is deliberately done so in t0000-basic.sh
196because the things the very basic core test tries to achieve is
197to serve as a basis for people who are changing the GIT internal
198drastically. For these people, after making certain changes,
199not seeing failures from the basic test _is_ a failure. And
200such drastic changes to the core GIT that even changes these
201otherwise supposedly stable object IDs should be accompanied by
202an update to t0000-basic.sh.
203
204However, other tests that simply rely on basic parts of the core
205GIT working properly should not have that level of intimate
206knowledge of the core GIT internals. If all the test scripts
207hardcoded the object IDs like t0000-basic.sh does, that defeats
208the purpose of t0000-basic.sh, which is to isolate that level of
209validation in one place. Your test also ends up needing
210updating when such a change to the internal happens, so do _not_
211do it and leave the low level of validation to t0000-basic.sh.