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 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) 76 7 - the porcelainish commands concerning the working tree 77 8 - the porcelainish commands concerning forensics 78 9 - the git tools 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 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 93 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 # 105 106 test_description='xxx test (option --frotz) 107 108 This test registers the following structure in the cache 109 and tries to run git-ls-files with option --frotz.' 110 111 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. 133 134 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 NOT the opposite of test_expect_success, but is used 164 to mark a test that demonstrates a known breakage. Unlike 165 the usual test_expect_success tests, which say "ok" on 166 success and "FAIL" on failure, this will say "FIXED" on 167 success and "still broken" on failure. Failures from these 168 tests won't cause -i (immediate) to stop. 169 170 - test_debug <script> 171 172 This takes a single argument, <script>, and evaluates it only 173 when the test script is started with --debug command line 174 argument. This is primarily meant for use during the 175 development of a new test script. 176 177 - test_done 178 179 Your test script must have test_done at the end. Its purpose 180 is to summarize successes and failures in the test script and 181 exit with an appropriate error code. 182 183 184Tips for Writing Tests 185---------------------- 186 187As with any programming projects, existing programs are the best 188source of the information. However, do _not_ emulate 189t0000-basic.sh when writing your tests. The test is special in 190that it tries to validate the very core of GIT. For example, it 191knows that there will be 256 subdirectories under .git/objects/, 192and it knows that the object ID of an empty tree is a certain 19340-byte string. This is deliberately done so in t0000-basic.sh 194because the things the very basic core test tries to achieve is 195to serve as a basis for people who are changing the GIT internal 196drastically. For these people, after making certain changes, 197not seeing failures from the basic test _is_ a failure. And 198such drastic changes to the core GIT that even changes these 199otherwise supposedly stable object IDs should be accompanied by 200an update to t0000-basic.sh. 201 202However, other tests that simply rely on basic parts of the core 203GIT working properly should not have that level of intimate 204knowledge of the core GIT internals. If all the test scripts 205hardcoded the object IDs like t0000-basic.sh does, that defeats 206the purpose of t0000-basic.sh, which is to isolate that level of 207validation in one place. Your test also ends up needing 208updating when such a change to the internal happens, so do _not_ 209do it and leave the low level of validation to t0000-basic.sh.