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. 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--long-tests:: 58 This causes additional long-running tests to be run (where 59 available), for more exhaustive testing. 60 61 62Naming Tests 63------------ 64 65The test files are named as: 66 67 tNNNN-commandname-details.sh 68 69where N is a decimal digit. 70 71First digit tells the family: 72 73 0 - the absolute basics and global stuff 74 1 - the basic commands concerning database 75 2 - the basic commands concerning the working tree 76 3 - the other basic commands (e.g. ls-files) 77 4 - the diff commands 78 5 - the pull and exporting commands 79 6 - the revision tree commands (even e.g. merge-base) 80 7 - the porcelainish commands concerning the working tree 81 8 - the porcelainish commands concerning forensics 82 9 - the git tools 83 84Second digit tells the particular command we are testing. 85 86Third digit (optionally) tells the particular switch or group of switches 87we are testing. 88 89If you create files under t/ directory (i.e. here) that is not 90the top-level test script, never name the file to match the above 91pattern. The Makefile here considers all such files as the 92top-level test script and tries to run all of them. A care is 93especially needed if you are creating a common test library 94file, similar to test-lib.sh, because such a library file may 95not be suitable for standalone execution. 96 97 98Writing Tests 99------------- 100 101The test script is written as a shell script. It should start 102with the standard "#!/bin/sh" with copyright notices, and an 103assignment to variable 'test_description', like this: 104 105 #!/bin/sh 106 # 107 # Copyright (c) 2005 Junio C Hamano 108 # 109 110 test_description='xxx test (option --frotz) 111 112 This test registers the following structure in the cache 113 and tries to run git-ls-files with option --frotz.' 114 115 116Source 'test-lib.sh' 117-------------------- 118 119After assigning test_description, the test script should source 120test-lib.sh like this: 121 122 . ./test-lib.sh 123 124This test harness library does the following things: 125 126 - If the script is invoked with command line argument --help 127 (or -h), it shows the test_description and exits. 128 129 - Creates an empty test directory with an empty .git/objects 130 database and chdir(2) into it. This directory is 't/trash directory' 131 if you must know, but I do not think you care. 132 133 - Defines standard test helper functions for your scripts to 134 use. These functions are designed to make all scripts behave 135 consistently when command line arguments --verbose (or -v), 136 --debug (or -d), and --immediate (or -i) is given. 137 138 139End with test_done 140------------------ 141 142Your script will be a sequence of tests, using helper functions 143from the test harness library. At the end of the script, call 144'test_done'. 145 146 147Test harness library 148-------------------- 149 150There are a handful helper functions defined in the test harness 151library for your script to use. 152 153 - test_expect_success <message> <script> 154 155 This takes two strings as parameter, and evaluates the 156 <script>. If it yields success, test is considered 157 successful. <message> should state what it is testing. 158 159 Example: 160 161 test_expect_success \ 162 'git-write-tree should be able to write an empty tree.' \ 163 'tree=$(git-write-tree)' 164 165 - test_expect_failure <message> <script> 166 167 This is NOT the opposite of test_expect_success, but is used 168 to mark a test that demonstrates a known breakage. Unlike 169 the usual test_expect_success tests, which say "ok" on 170 success and "FAIL" on failure, this will say "FIXED" on 171 success and "still broken" on failure. Failures from these 172 tests won't cause -i (immediate) to stop. 173 174 - test_debug <script> 175 176 This takes a single argument, <script>, and evaluates it only 177 when the test script is started with --debug command line 178 argument. This is primarily meant for use during the 179 development of a new test script. 180 181 - test_done 182 183 Your test script must have test_done at the end. Its purpose 184 is to summarize successes and failures in the test script and 185 exit with an appropriate error code. 186 187 188Tips for Writing Tests 189---------------------- 190 191As with any programming projects, existing programs are the best 192source of the information. However, do _not_ emulate 193t0000-basic.sh when writing your tests. The test is special in 194that it tries to validate the very core of GIT. For example, it 195knows that there will be 256 subdirectories under .git/objects/, 196and it knows that the object ID of an empty tree is a certain 19740-byte string. This is deliberately done so in t0000-basic.sh 198because the things the very basic core test tries to achieve is 199to serve as a basis for people who are changing the GIT internal 200drastically. For these people, after making certain changes, 201not seeing failures from the basic test _is_ a failure. And 202such drastic changes to the core GIT that even changes these 203otherwise supposedly stable object IDs should be accompanied by 204an update to t0000-basic.sh. 205 206However, other tests that simply rely on basic parts of the core 207GIT working properly should not have that level of intimate 208knowledge of the core GIT internals. If all the test scripts 209hardcoded the object IDs like t0000-basic.sh does, that defeats 210the purpose of t0000-basic.sh, which is to isolate that level of 211validation in one place. Your test also ends up needing 212updating when such a change to the internal happens, so do _not_ 213do it and leave the low level of validation to t0000-basic.sh.