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 *** 21 * ok 1: .git/objects should be empty after git-init in an empty repo. 22 * ok 2: .git/objects should have 256 subdirectories. 23 * ok 3: git-update-index without --add should fail adding. 24 ... 25 * ok 23: no diff after checkout and git-update-index --refresh. 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 35 $ sh ./t3001-ls-files-killed.sh 36 * ok 1: git-update-index --add to add various paths. 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, or by setting GIT_TEST_OPTS 43appropriately before running "make". 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 58--long-tests:: 59 This causes additional long-running tests to be run (where 60 available), for more exhaustive testing. 61 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. 67 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 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) 114 7 - the porcelainish commands concerning the working tree 115 8 - the porcelainish commands concerning forensics 116 9 - the git tools 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 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. 130 131 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 # 143 144 test_description='xxx test (option --frotz) 145 146 This test registers the following structure in the cache 147 and tries to run git-ls-files with option --frotz.' 148 149 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 164 database and chdir(2) into it. This directory is 't/trash directory' 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. 171 172 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> 200 201 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. 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. 220 221 - 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. 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.