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-db 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 77Second digit tells the particular command we are testing. 78 79Third digit (optionally) tells the particular switch or group of switches 80we are testing. 81 82If you create files under t/ directory (i.e. here) that is not 83the top-level test script, never name the file to match the above 84pattern. The Makefile here considers all such files as the 85top-level test script and tries to run all of them. A care is 86especially needed if you are creating a common test library 87file, similar to test-lib.sh, because such a library file may 88not be suitable for standalone execution. 89 90 91Writing Tests 92------------- 93 94The test script is written as a shell script. It should start 95with the standard "#!/bin/sh" with copyright notices, and an 96assignment to variable 'test_description', like this: 97 98 #!/bin/sh 99 # 100 # Copyright (c) 2005 Junio C Hamano 101 # 102 103 test_description='xxx test (option --frotz) 104 105 This test registers the following structure in the cache 106 and tries to run git-ls-files with option --frotz.' 107 108 109Source 'test-lib.sh' 110-------------------- 111 112After assigning test_description, the test script should source 113test-lib.sh like this: 114 115 . ./test-lib.sh 116 117This test harness library does the following things: 118 119 - If the script is invoked with command line argument --help 120 (or -h), it shows the test_description and exits. 121 122 - Creates an empty test directory with an empty .git/objects 123 database and chdir(2) into it. This directory is 't/trash' 124 if you must know, but I do not think you care. 125 126 - Defines standard test helper functions for your scripts to 127 use. These functions are designed to make all scripts behave 128 consistently when command line arguments --verbose (or -v), 129 --debug (or -d), and --immediate (or -i) is given. 130 131 132End with test_done 133------------------ 134 135Your script will be a sequence of tests, using helper functions 136from the test harness library. At the end of the script, call 137'test_done'. 138 139 140Test harness library 141-------------------- 142 143There are a handful helper functions defined in the test harness 144library for your script to use. 145 146 - test_expect_success <message> <script> 147 148 This takes two strings as parameter, and evaluates the 149 <script>. If it yields success, test is considered 150 successful. <message> should state what it is testing. 151 152 Example: 153 154 test_expect_success \ 155 'git-write-tree should be able to write an empty tree.' \ 156 'tree=$(git-write-tree)' 157 158 - test_expect_failure <message> <script> 159 160 This is the opposite of test_expect_success. If <script> 161 yields success, test is considered a failure. 162 163 Example: 164 165 test_expect_failure \ 166 'git-update-index without --add should fail adding.' \ 167 'git-update-index should-be-empty' 168 169 - test_debug <script> 170 171 This takes a single argument, <script>, and evaluates it only 172 when the test script is started with --debug command line 173 argument. This is primarily meant for use during the 174 development of a new test script. 175 176 - test_done 177 178 Your test script must have test_done at the end. Its purpose 179 is to summarize successes and failures in the test script and 180 exit with an appropriate error code. 181 182 183Tips for Writing Tests 184---------------------- 185 186As with any programming projects, existing programs are the best 187source of the information. However, do _not_ emulate 188t0000-basic.sh when writing your tests. The test is special in 189that it tries to validate the very core of GIT. For example, it 190knows that there will be 256 subdirectories under .git/objects/, 191and it knows that the object ID of an empty tree is a certain 19240-byte string. This is deliberately done so in t0000-basic.sh 193because the things the very basic core test tries to achieve is 194to serve as a basis for people who are changing the GIT internal 195drastically. For these people, after making certain changes, 196not seeing failures from the basic test _is_ a failure. And 197such drastic changes to the core GIT that even changes these 198otherwise supposedly stable object IDs should be accompanied by 199an update to t0000-basic.sh. 200 201However, other tests that simply rely on basic parts of the core 202GIT working properly should not have that level of intimate 203knowledge of the core GIT internals. If all the test scripts 204hardcoded the object IDs like t0000-basic.sh does, that defeats 205the purpose of t0000-basic.sh, which is to isolate that level of 206validation in one place. Your test also ends up needing 207updating when such a change to the internal happens, so do _not_ 208do it and leave the low level of validation to t0000-basic.sh.