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 3 subdirectories. 23 ok 3 - success is reported like this 24 ... 25 ok 43 - very long name in the index handled sanely 26 # fixed 1 known breakage(s) 27 # still have 1 known breakage(s) 28 # passed all remaining 42 test(s) 29 1..43 30 *** t0001-init.sh *** 31 ok 1 - plain 32 ok 2 - plain with GIT_WORK_TREE 33 ok 3 - plain bare 34 35Since the tests all output TAP (see http://testanything.org) they can 36be run with any TAP harness. Here's an example of parallel testing 37powered by a recent version of prove(1): 38 39 $ prove --timer --jobs 15 ./t[0-9]*.sh 40 [19:17:33] ./t0005-signals.sh ................................... ok 36 ms 41 [19:17:33] ./t0022-crlf-rename.sh ............................... ok 69 ms 42 [19:17:33] ./t0024-crlf-archive.sh .............................. ok 154 ms 43 [19:17:33] ./t0004-unwritable.sh ................................ ok 289 ms 44 [19:17:33] ./t0002-gitfile.sh ................................... ok 480 ms 45 ===( 102;0 25/? 6/? 5/? 16/? 1/? 4/? 2/? 1/? 3/? 1... )=== 46 47prove and other harnesses come with a lot of useful options. The 48--state option in particular is very useful: 49 50 # Repeat until no more failures 51 $ prove -j 15 --state=failed,save ./t[0-9]*.sh 52 53You can give DEFAULT_TEST_TARGET=prove on the make command (or define it 54in config.mak) to cause "make test" to run tests under prove. 55GIT_PROVE_OPTS can be used to pass additional options, e.g. 56 57 $ make DEFAULT_TEST_TARGET=prove GIT_PROVE_OPTS='--timer --jobs 16' test 58 59You can also run each test individually from command line, like this: 60 61 $ sh ./t3010-ls-files-killed-modified.sh 62 ok 1 - git update-index --add to add various paths. 63 ok 2 - git ls-files -k to show killed files. 64 ok 3 - validate git ls-files -k output. 65 ok 4 - git ls-files -m to show modified files. 66 ok 5 - validate git ls-files -m output. 67 # passed all 5 test(s) 68 1..5 69 70You can pass --verbose (or -v), --debug (or -d), and --immediate 71(or -i) command line argument to the test, or by setting GIT_TEST_OPTS 72appropriately before running "make". 73 74-v:: 75--verbose:: 76 This makes the test more verbose. Specifically, the 77 command being run and their output if any are also 78 output. 79 80--verbose-only=<pattern>:: 81 Like --verbose, but the effect is limited to tests with 82 numbers matching <pattern>. The number matched against is 83 simply the running count of the test within the file. 84 85-x:: 86 Turn on shell tracing (i.e., `set -x`) during the tests 87 themselves. Implies `--verbose`. 88 Ignored in test scripts that set the variable 'test_untraceable' 89 to a non-empty value, unless it's run with a Bash version 90 supporting BASH_XTRACEFD, i.e. v4.1 or later. 91 92-d:: 93--debug:: 94 This may help the person who is developing a new test. 95 It causes the command defined with test_debug to run. 96 The "trash" directory (used to store all temporary data 97 during testing) is not deleted even if there are no 98 failed tests so that you can inspect its contents after 99 the test finished. 100 101-i:: 102--immediate:: 103 This causes the test to immediately exit upon the first 104 failed test. Cleanup commands requested with 105 test_when_finished are not executed if the test failed, 106 in order to keep the state for inspection by the tester 107 to diagnose the bug. 108 109-l:: 110--long-tests:: 111 This causes additional long-running tests to be run (where 112 available), for more exhaustive testing. 113 114-r:: 115--run=<test-selector>:: 116 Run only the subset of tests indicated by 117 <test-selector>. See section "Skipping Tests" below for 118 <test-selector> syntax. 119 120--valgrind=<tool>:: 121 Execute all Git binaries under valgrind tool <tool> and exit 122 with status 126 on errors (just like regular tests, this will 123 only stop the test script when running under -i). 124 125 Since it makes no sense to run the tests with --valgrind and 126 not see any output, this option implies --verbose. For 127 convenience, it also implies --tee. 128 129 <tool> defaults to 'memcheck', just like valgrind itself. 130 Other particularly useful choices include 'helgrind' and 131 'drd', but you may use any tool recognized by your valgrind 132 installation. 133 134 As a special case, <tool> can be 'memcheck-fast', which uses 135 memcheck but disables --track-origins. Use this if you are 136 running tests in bulk, to see if there are _any_ memory 137 issues. 138 139 Note that memcheck is run with the option --leak-check=no, 140 as the git process is short-lived and some errors are not 141 interesting. In order to run a single command under the same 142 conditions manually, you should set GIT_VALGRIND to point to 143 the 't/valgrind/' directory and use the commands under 144 't/valgrind/bin/'. 145 146--valgrind-only=<pattern>:: 147 Like --valgrind, but the effect is limited to tests with 148 numbers matching <pattern>. The number matched against is 149 simply the running count of the test within the file. 150 151--tee:: 152 In addition to printing the test output to the terminal, 153 write it to files named 't/test-results/$TEST_NAME.out'. 154 As the names depend on the tests' file names, it is safe to 155 run the tests with this option in parallel. 156 157-V:: 158--verbose-log:: 159 Write verbose output to the same logfile as `--tee`, but do 160 _not_ write it to stdout. Unlike `--tee --verbose`, this option 161 is safe to use when stdout is being consumed by a TAP parser 162 like `prove`. Implies `--tee` and `--verbose`. 163 164--with-dashes:: 165 By default tests are run without dashed forms of 166 commands (like git-commit) in the PATH (it only uses 167 wrappers from ../bin-wrappers). Use this option to include 168 the build directory (..) in the PATH, which contains all 169 the dashed forms of commands. This option is currently 170 implied by other options like --valgrind and 171 GIT_TEST_INSTALLED. 172 173--root=<directory>:: 174 Create "trash" directories used to store all temporary data during 175 testing under <directory>, instead of the t/ directory. 176 Using this option with a RAM-based filesystem (such as tmpfs) 177 can massively speed up the test suite. 178 179--chain-lint:: 180--no-chain-lint:: 181 If --chain-lint is enabled, the test harness will check each 182 test to make sure that it properly "&&-chains" all commands (so 183 that a failure in the middle does not go unnoticed by the final 184 exit code of the test). This check is performed in addition to 185 running the tests themselves. You may also enable or disable 186 this feature by setting the GIT_TEST_CHAIN_LINT environment 187 variable to "1" or "0", respectively. 188 189You can also set the GIT_TEST_INSTALLED environment variable to 190the bindir of an existing git installation to test that installation. 191You still need to have built this git sandbox, from which various 192test-* support programs, templates, and perl libraries are used. 193If your installed git is incomplete, it will silently test parts of 194your built version instead. 195 196When using GIT_TEST_INSTALLED, you can also set GIT_TEST_EXEC_PATH to 197override the location of the dashed-form subcommands (what 198GIT_EXEC_PATH would be used for during normal operation). 199GIT_TEST_EXEC_PATH defaults to `$GIT_TEST_INSTALLED/git --exec-path`. 200 201 202Skipping Tests 203-------------- 204 205In some environments, certain tests have no way of succeeding 206due to platform limitation, such as lack of 'unzip' program, or 207filesystem that do not allow arbitrary sequence of non-NUL bytes 208as pathnames. 209 210You should be able to say something like 211 212 $ GIT_SKIP_TESTS=t9200.8 sh ./t9200-git-cvsexport-commit.sh 213 214and even: 215 216 $ GIT_SKIP_TESTS='t[0-4]??? t91?? t9200.8' make 217 218to omit such tests. The value of the environment variable is a 219SP separated list of patterns that tells which tests to skip, 220and either can match the "t[0-9]{4}" part to skip the whole 221test, or t[0-9]{4} followed by ".$number" to say which 222particular test to skip. 223 224For an individual test suite --run could be used to specify that 225only some tests should be run or that some tests should be 226excluded from a run. 227 228The argument for --run is a list of individual test numbers or 229ranges with an optional negation prefix that define what tests in 230a test suite to include in the run. A range is two numbers 231separated with a dash and matches a range of tests with both ends 232been included. You may omit the first or the second number to 233mean "from the first test" or "up to the very last test" 234respectively. 235 236Optional prefix of '!' means that the test or a range of tests 237should be excluded from the run. 238 239If --run starts with an unprefixed number or range the initial 240set of tests to run is empty. If the first item starts with '!' 241all the tests are added to the initial set. After initial set is 242determined every test number or range is added or excluded from 243the set one by one, from left to right. 244 245Individual numbers or ranges could be separated either by a space 246or a comma. 247 248For example, to run only tests up to a specific test (21), one 249could do this: 250 251 $ sh ./t9200-git-cvsexport-commit.sh --run='1-21' 252 253or this: 254 255 $ sh ./t9200-git-cvsexport-commit.sh --run='-21' 256 257Common case is to run several setup tests (1, 2, 3) and then a 258specific test (21) that relies on that setup: 259 260 $ sh ./t9200-git-cvsexport-commit.sh --run='1 2 3 21' 261 262or: 263 264 $ sh ./t9200-git-cvsexport-commit.sh --run=1,2,3,21 265 266or: 267 268 $ sh ./t9200-git-cvsexport-commit.sh --run='-3 21' 269 270As noted above, the test set is built by going through the items 271from left to right, so this: 272 273 $ sh ./t9200-git-cvsexport-commit.sh --run='1-4 !3' 274 275will run tests 1, 2, and 4. Items that come later have higher 276precedence. It means that this: 277 278 $ sh ./t9200-git-cvsexport-commit.sh --run='!3 1-4' 279 280would just run tests from 1 to 4, including 3. 281 282You may use negation with ranges. The following will run all 283test in the test suite except from 7 up to 11: 284 285 $ sh ./t9200-git-cvsexport-commit.sh --run='!7-11' 286 287Some tests in a test suite rely on the previous tests performing 288certain actions, specifically some tests are designated as 289"setup" test, so you cannot _arbitrarily_ disable one test and 290expect the rest to function correctly. 291 292--run is mostly useful when you want to focus on a specific test 293and know what setup is needed for it. Or when you want to run 294everything up to a certain test. 295 296 297Running tests with special setups 298--------------------------------- 299 300The whole test suite could be run to test some special features 301that cannot be easily covered by a few specific test cases. These 302could be enabled by running the test suite with correct GIT_TEST_ 303environment set. 304 305GIT_TEST_SPLIT_INDEX=<boolean> forces split-index mode on the whole 306test suite. Accept any boolean values that are accepted by git-config. 307 308GIT_TEST_FULL_IN_PACK_ARRAY=<boolean> exercises the uncommon 309pack-objects code path where there are more than 1024 packs even if 310the actual number of packs in repository is below this limit. Accept 311any boolean values that are accepted by git-config. 312 313GIT_TEST_OE_SIZE=<n> exercises the uncommon pack-objects code path 314where we do not cache object size in memory and read it from existing 315packs on demand. This normally only happens when the object size is 316over 2GB. This variable forces the code path on any object larger than 317<n> bytes. 318 319GIT_TEST_OE_DELTA_SIZE=<n> exercises the uncommon pack-objects code 320path where deltas larger than this limit require extra memory 321allocation for bookkeeping. 322 323GIT_TEST_VALIDATE_INDEX_CACHE_ENTRIES=<boolean> checks that cache-tree 324records are valid when the index is written out or after a merge. This 325is mostly to catch missing invalidation. Default is true. 326 327GIT_TEST_COMMIT_GRAPH=<boolean>, when true, forces the commit-graph to 328be written after every 'git commit' command, and overrides the 329'core.commitGraph' setting to true. 330 331GIT_TEST_FSMONITOR=$PWD/t7519/fsmonitor-all exercises the fsmonitor 332code path for utilizing a file system monitor to speed up detecting 333new or changed files. 334 335GIT_TEST_INDEX_VERSION=<n> exercises the index read/write code path 336for the index version specified. Can be set to any valid version 337(currently 2, 3, or 4). 338 339GIT_TEST_PRELOAD_INDEX=<boolean> exercises the preload-index code path 340by overriding the minimum number of cache entries required per thread. 341 342GIT_TEST_REBASE_USE_BUILTIN=<boolean>, when false, disables the 343builtin version of git-rebase. See 'rebase.useBuiltin' in 344git-config(1). 345 346GIT_TEST_INDEX_THREADS=<n> enables exercising the multi-threaded loading 347of the index for the whole test suite by bypassing the default number of 348cache entries and thread minimums. Setting this to 1 will make the 349index loading single threaded. 350 351GIT_TEST_MULTI_PACK_INDEX=<boolean>, when true, forces the multi-pack- 352index to be written after every 'git repack' command, and overrides the 353'core.multiPackIndex' setting to true. 354 355Naming Tests 356------------ 357 358The test files are named as: 359 360 tNNNN-commandname-details.sh 361 362where N is a decimal digit. 363 364First digit tells the family: 365 366 0 - the absolute basics and global stuff 367 1 - the basic commands concerning database 368 2 - the basic commands concerning the working tree 369 3 - the other basic commands (e.g. ls-files) 370 4 - the diff commands 371 5 - the pull and exporting commands 372 6 - the revision tree commands (even e.g. merge-base) 373 7 - the porcelainish commands concerning the working tree 374 8 - the porcelainish commands concerning forensics 375 9 - the git tools 376 377Second digit tells the particular command we are testing. 378 379Third digit (optionally) tells the particular switch or group of switches 380we are testing. 381 382If you create files under t/ directory (i.e. here) that is not 383the top-level test script, never name the file to match the above 384pattern. The Makefile here considers all such files as the 385top-level test script and tries to run all of them. Care is 386especially needed if you are creating a common test library 387file, similar to test-lib.sh, because such a library file may 388not be suitable for standalone execution. 389 390 391Writing Tests 392------------- 393 394The test script is written as a shell script. It should start 395with the standard "#!/bin/sh", and an 396assignment to variable 'test_description', like this: 397 398 #!/bin/sh 399 400 test_description='xxx test (option --frotz) 401 402 This test registers the following structure in the cache 403 and tries to run git-ls-files with option --frotz.' 404 405 406Source 'test-lib.sh' 407-------------------- 408 409After assigning test_description, the test script should source 410test-lib.sh like this: 411 412 . ./test-lib.sh 413 414This test harness library does the following things: 415 416 - If the script is invoked with command line argument --help 417 (or -h), it shows the test_description and exits. 418 419 - Creates an empty test directory with an empty .git/objects database 420 and chdir(2) into it. This directory is 't/trash 421 directory.$test_name_without_dotsh', with t/ subject to change by 422 the --root option documented above. 423 424 - Defines standard test helper functions for your scripts to 425 use. These functions are designed to make all scripts behave 426 consistently when command line arguments --verbose (or -v), 427 --debug (or -d), and --immediate (or -i) is given. 428 429Do's & don'ts 430------------- 431 432Here are a few examples of things you probably should and shouldn't do 433when writing tests. 434 435Here are the "do's:" 436 437 - Put all code inside test_expect_success and other assertions. 438 439 Even code that isn't a test per se, but merely some setup code 440 should be inside a test assertion. 441 442 - Chain your test assertions 443 444 Write test code like this: 445 446 git merge foo && 447 git push bar && 448 test ... 449 450 Instead of: 451 452 git merge hla 453 git push gh 454 test ... 455 456 That way all of the commands in your tests will succeed or fail. If 457 you must ignore the return value of something, consider using a 458 helper function (e.g. use sane_unset instead of unset, in order 459 to avoid unportable return value for unsetting a variable that was 460 already unset), or prepending the command with test_might_fail or 461 test_must_fail. 462 463 - Check the test coverage for your tests. See the "Test coverage" 464 below. 465 466 Don't blindly follow test coverage metrics; if a new function you added 467 doesn't have any coverage, then you're probably doing something wrong, 468 but having 100% coverage doesn't necessarily mean that you tested 469 everything. 470 471 Tests that are likely to smoke out future regressions are better 472 than tests that just inflate the coverage metrics. 473 474 - When a test checks for an absolute path that a git command generated, 475 construct the expected value using $(pwd) rather than $PWD, 476 $TEST_DIRECTORY, or $TRASH_DIRECTORY. It makes a difference on 477 Windows, where the shell (MSYS bash) mangles absolute path names. 478 For details, see the commit message of 4114156ae9. 479 480 - Remember that inside the <script> part, the standard output and 481 standard error streams are discarded, and the test harness only 482 reports "ok" or "not ok" to the end user running the tests. Under 483 --verbose, they are shown to help debug the tests. 484 485And here are the "don'ts:" 486 487 - Don't exit() within a <script> part. 488 489 The harness will catch this as a programming error of the test. 490 Use test_done instead if you need to stop the tests early (see 491 "Skipping tests" below). 492 493 - Don't use '! git cmd' when you want to make sure the git command 494 exits with failure in a controlled way by calling "die()". Instead, 495 use 'test_must_fail git cmd'. This will signal a failure if git 496 dies in an unexpected way (e.g. segfault). 497 498 On the other hand, don't use test_must_fail for running regular 499 platform commands; just use '! cmd'. We are not in the business 500 of verifying that the world given to us sanely works. 501 502 - Don't feed the output of a git command to a pipe, as in: 503 504 git -C repo ls-files | 505 xargs -n 1 basename | 506 grep foo 507 508 which will discard git's exit code and may mask a crash. In the 509 above example, all exit codes are ignored except grep's. 510 511 Instead, write the output of that command to a temporary 512 file with ">" or assign it to a variable with "x=$(git ...)" rather 513 than pipe it. 514 515 - Don't use command substitution in a way that discards git's exit 516 code. When assigning to a variable, the exit code is not discarded, 517 e.g.: 518 519 x=$(git cat-file -p $sha) && 520 ... 521 522 is OK because a crash in "git cat-file" will cause the "&&" chain 523 to fail, but: 524 525 test "refs/heads/foo" = "$(git symbolic-ref HEAD)" 526 527 is not OK and a crash in git could go undetected. 528 529 - Don't use perl without spelling it as "$PERL_PATH". This is to help 530 our friends on Windows where the platform Perl often adds CR before 531 the end of line, and they bundle Git with a version of Perl that 532 does not do so, whose path is specified with $PERL_PATH. Note that we 533 provide a "perl" function which uses $PERL_PATH under the hood, so 534 you do not need to worry when simply running perl in the test scripts 535 (but you do, for example, on a shebang line or in a sub script 536 created via "write_script"). 537 538 - Don't use sh without spelling it as "$SHELL_PATH", when the script 539 can be misinterpreted by broken platform shell (e.g. Solaris). 540 541 - Don't chdir around in tests. It is not sufficient to chdir to 542 somewhere and then chdir back to the original location later in 543 the test, as any intermediate step can fail and abort the test, 544 causing the next test to start in an unexpected directory. Do so 545 inside a subshell if necessary. 546 547 - Don't save and verify the standard error of compound commands, i.e. 548 group commands, subshells, and shell functions (except test helper 549 functions like 'test_must_fail') like this: 550 551 ( cd dir && git cmd ) 2>error && 552 test_cmp expect error 553 554 When running the test with '-x' tracing, then the trace of commands 555 executed in the compound command will be included in standard error 556 as well, quite possibly throwing off the subsequent checks examining 557 the output. Instead, save only the relevant git command's standard 558 error: 559 560 ( cd dir && git cmd 2>../error ) && 561 test_cmp expect error 562 563 - Don't break the TAP output 564 565 The raw output from your test may be interpreted by a TAP harness. TAP 566 harnesses will ignore everything they don't know about, but don't step 567 on their toes in these areas: 568 569 - Don't print lines like "$x..$y" where $x and $y are integers. 570 571 - Don't print lines that begin with "ok" or "not ok". 572 573 TAP harnesses expect a line that begins with either "ok" and "not 574 ok" to signal a test passed or failed (and our harness already 575 produces such lines), so your script shouldn't emit such lines to 576 their output. 577 578 You can glean some further possible issues from the TAP grammar 579 (see https://metacpan.org/pod/TAP::Parser::Grammar#TAP-GRAMMAR) 580 but the best indication is to just run the tests with prove(1), 581 it'll complain if anything is amiss. 582 583 584Skipping tests 585-------------- 586 587If you need to skip tests you should do so by using the three-arg form 588of the test_* functions (see the "Test harness library" section 589below), e.g.: 590 591 test_expect_success PERL 'I need Perl' ' 592 perl -e "hlagh() if unf_unf()" 593 ' 594 595The advantage of skipping tests like this is that platforms that don't 596have the PERL and other optional dependencies get an indication of how 597many tests they're missing. 598 599If the test code is too hairy for that (i.e. does a lot of setup work 600outside test assertions) you can also skip all remaining tests by 601setting skip_all and immediately call test_done: 602 603 if ! test_have_prereq PERL 604 then 605 skip_all='skipping perl interface tests, perl not available' 606 test_done 607 fi 608 609The string you give to skip_all will be used as an explanation for why 610the test was skipped. 611 612End with test_done 613------------------ 614 615Your script will be a sequence of tests, using helper functions 616from the test harness library. At the end of the script, call 617'test_done'. 618 619 620Test harness library 621-------------------- 622 623There are a handful helper functions defined in the test harness 624library for your script to use. 625 626 - test_expect_success [<prereq>] <message> <script> 627 628 Usually takes two strings as parameters, and evaluates the 629 <script>. If it yields success, test is considered 630 successful. <message> should state what it is testing. 631 632 Example: 633 634 test_expect_success \ 635 'git-write-tree should be able to write an empty tree.' \ 636 'tree=$(git-write-tree)' 637 638 If you supply three parameters the first will be taken to be a 639 prerequisite; see the test_set_prereq and test_have_prereq 640 documentation below: 641 642 test_expect_success TTY 'git --paginate rev-list uses a pager' \ 643 ' ... ' 644 645 You can also supply a comma-separated list of prerequisites, in the 646 rare case where your test depends on more than one: 647 648 test_expect_success PERL,PYTHON 'yo dawg' \ 649 ' test $(perl -E 'print eval "1 +" . qx[python -c "print 2"]') == "4" ' 650 651 - test_expect_failure [<prereq>] <message> <script> 652 653 This is NOT the opposite of test_expect_success, but is used 654 to mark a test that demonstrates a known breakage. Unlike 655 the usual test_expect_success tests, which say "ok" on 656 success and "FAIL" on failure, this will say "FIXED" on 657 success and "still broken" on failure. Failures from these 658 tests won't cause -i (immediate) to stop. 659 660 Like test_expect_success this function can optionally use a three 661 argument invocation with a prerequisite as the first argument. 662 663 - test_debug <script> 664 665 This takes a single argument, <script>, and evaluates it only 666 when the test script is started with --debug command line 667 argument. This is primarily meant for use during the 668 development of a new test script. 669 670 - debug <git-command> 671 672 Run a git command inside a debugger. This is primarily meant for 673 use when debugging a failing test script. 674 675 - test_done 676 677 Your test script must have test_done at the end. Its purpose 678 is to summarize successes and failures in the test script and 679 exit with an appropriate error code. 680 681 - test_tick 682 683 Make commit and tag names consistent by setting the author and 684 committer times to defined state. Subsequent calls will 685 advance the times by a fixed amount. 686 687 - test_commit <message> [<filename> [<contents>]] 688 689 Creates a commit with the given message, committing the given 690 file with the given contents (default for both is to reuse the 691 message string), and adds a tag (again reusing the message 692 string as name). Calls test_tick to make the SHA-1s 693 reproducible. 694 695 - test_merge <message> <commit-or-tag> 696 697 Merges the given rev using the given message. Like test_commit, 698 creates a tag and calls test_tick before committing. 699 700 - test_set_prereq <prereq> 701 702 Set a test prerequisite to be used later with test_have_prereq. The 703 test-lib will set some prerequisites for you, see the 704 "Prerequisites" section below for a full list of these. 705 706 Others you can set yourself and use later with either 707 test_have_prereq directly, or the three argument invocation of 708 test_expect_success and test_expect_failure. 709 710 - test_have_prereq <prereq> 711 712 Check if we have a prerequisite previously set with test_set_prereq. 713 The most common way to use this explicitly (as opposed to the 714 implicit use when an argument is passed to test_expect_*) is to skip 715 all the tests at the start of the test script if we don't have some 716 essential prerequisite: 717 718 if ! test_have_prereq PERL 719 then 720 skip_all='skipping perl interface tests, perl not available' 721 test_done 722 fi 723 724 - test_external [<prereq>] <message> <external> <script> 725 726 Execute a <script> with an <external> interpreter (like perl). This 727 was added for tests like t9700-perl-git.sh which do most of their 728 work in an external test script. 729 730 test_external \ 731 'GitwebCache::*FileCache*' \ 732 perl "$TEST_DIRECTORY"/t9503/test_cache_interface.pl 733 734 If the test is outputting its own TAP you should set the 735 test_external_has_tap variable somewhere before calling the first 736 test_external* function. See t9700-perl-git.sh for an example. 737 738 # The external test will outputs its own plan 739 test_external_has_tap=1 740 741 - test_external_without_stderr [<prereq>] <message> <external> <script> 742 743 Like test_external but fail if there's any output on stderr, 744 instead of checking the exit code. 745 746 test_external_without_stderr \ 747 'Perl API' \ 748 perl "$TEST_DIRECTORY"/t9700/test.pl 749 750 - test_expect_code <exit-code> <command> 751 752 Run a command and ensure that it exits with the given exit code. 753 For example: 754 755 test_expect_success 'Merge with d/f conflicts' ' 756 test_expect_code 1 git merge "merge msg" B master 757 ' 758 759 - test_must_fail [<options>] <git-command> 760 761 Run a git command and ensure it fails in a controlled way. Use 762 this instead of "! <git-command>". When git-command dies due to a 763 segfault, test_must_fail diagnoses it as an error; "! <git-command>" 764 treats it as just another expected failure, which would let such a 765 bug go unnoticed. 766 767 Accepts the following options: 768 769 ok=<signal-name>[,<...>]: 770 Don't treat an exit caused by the given signal as error. 771 Multiple signals can be specified as a comma separated list. 772 Currently recognized signal names are: sigpipe, success. 773 (Don't use 'success', use 'test_might_fail' instead.) 774 775 - test_might_fail [<options>] <git-command> 776 777 Similar to test_must_fail, but tolerate success, too. Use this 778 instead of "<git-command> || :" to catch failures due to segv. 779 780 Accepts the same options as test_must_fail. 781 782 - test_cmp <expected> <actual> 783 784 Check whether the content of the <actual> file matches the 785 <expected> file. This behaves like "cmp" but produces more 786 helpful output when the test is run with "-v" option. 787 788 - test_cmp_rev <expected> <actual> 789 790 Check whether the <expected> rev points to the same commit as the 791 <actual> rev. 792 793 - test_line_count (= | -lt | -ge | ...) <length> <file> 794 795 Check whether a file has the length it is expected to. 796 797 - test_path_is_file <path> [<diagnosis>] 798 test_path_is_dir <path> [<diagnosis>] 799 test_path_is_missing <path> [<diagnosis>] 800 801 Check if the named path is a file, if the named path is a 802 directory, or if the named path does not exist, respectively, 803 and fail otherwise, showing the <diagnosis> text. 804 805 - test_when_finished <script> 806 807 Prepend <script> to a list of commands to run to clean up 808 at the end of the current test. If some clean-up command 809 fails, the test will not pass. 810 811 Example: 812 813 test_expect_success 'branch pointing to non-commit' ' 814 git rev-parse HEAD^{tree} >.git/refs/heads/invalid && 815 test_when_finished "git update-ref -d refs/heads/invalid" && 816 ... 817 ' 818 819 - test_write_lines <lines> 820 821 Write <lines> on standard output, one line per argument. 822 Useful to prepare multi-line files in a compact form. 823 824 Example: 825 826 test_write_lines a b c d e f g >foo 827 828 Is a more compact equivalent of: 829 cat >foo <<-EOF 830 a 831 b 832 c 833 d 834 e 835 f 836 g 837 EOF 838 839 840 - test_pause 841 842 This command is useful for writing and debugging tests and must be 843 removed before submitting. It halts the execution of the test and 844 spawns a shell in the trash directory. Exit the shell to continue 845 the test. Example: 846 847 test_expect_success 'test' ' 848 git do-something >actual && 849 test_pause && 850 test_cmp expected actual 851 ' 852 853 - test_ln_s_add <path1> <path2> 854 855 This function helps systems whose filesystem does not support symbolic 856 links. Use it to add a symbolic link entry to the index when it is not 857 important that the file system entry is a symbolic link, i.e., instead 858 of the sequence 859 860 ln -s foo bar && 861 git add bar 862 863 Sometimes it is possible to split a test in a part that does not need 864 the symbolic link in the file system and a part that does; then only 865 the latter part need be protected by a SYMLINKS prerequisite (see below). 866 867 - test_oid_init 868 869 This function loads facts and useful object IDs related to the hash 870 algorithm(s) in use from the files in t/oid-info. 871 872 - test_oid_cache 873 874 This function reads per-hash algorithm information from standard 875 input (usually a heredoc) in the format described in 876 t/oid-info/README. This is useful for test-specific values, such as 877 object IDs, which must vary based on the hash algorithm. 878 879 Certain fixed values, such as hash sizes and common placeholder 880 object IDs, can be loaded with test_oid_init (described above). 881 882 - test_oid <key> 883 884 This function looks up a value for the hash algorithm in use, based 885 on the key given. The value must have been loaded using 886 test_oid_init or test_oid_cache. Providing an unknown key is an 887 error. 888 889Prerequisites 890------------- 891 892These are the prerequisites that the test library predefines with 893test_have_prereq. 894 895See the prereq argument to the test_* functions in the "Test harness 896library" section above and the "test_have_prereq" function for how to 897use these, and "test_set_prereq" for how to define your own. 898 899 - PYTHON 900 901 Git wasn't compiled with NO_PYTHON=YesPlease. Wrap any tests that 902 need Python with this. 903 904 - PERL 905 906 Git wasn't compiled with NO_PERL=YesPlease. 907 908 Even without the PERL prerequisite, tests can assume there is a 909 usable perl interpreter at $PERL_PATH, though it need not be 910 particularly modern. 911 912 - POSIXPERM 913 914 The filesystem supports POSIX style permission bits. 915 916 - BSLASHPSPEC 917 918 Backslashes in pathspec are not directory separators. This is not 919 set on Windows. See 6fd1106a for details. 920 921 - EXECKEEPSPID 922 923 The process retains the same pid across exec(2). See fb9a2bea for 924 details. 925 926 - PIPE 927 928 The filesystem we're on supports creation of FIFOs (named pipes) 929 via mkfifo(1). 930 931 - SYMLINKS 932 933 The filesystem we're on supports symbolic links. E.g. a FAT 934 filesystem doesn't support these. See 704a3143 for details. 935 936 - SANITY 937 938 Test is not run by root user, and an attempt to write to an 939 unwritable file is expected to fail correctly. 940 941 - PCRE 942 943 Git was compiled with support for PCRE. Wrap any tests 944 that use git-grep --perl-regexp or git-grep -P in these. 945 946 - LIBPCRE1 947 948 Git was compiled with PCRE v1 support via 949 USE_LIBPCRE1=YesPlease. Wrap any PCRE using tests that for some 950 reason need v1 of the PCRE library instead of v2 in these. 951 952 - LIBPCRE2 953 954 Git was compiled with PCRE v2 support via 955 USE_LIBPCRE2=YesPlease. Wrap any PCRE using tests that for some 956 reason need v2 of the PCRE library instead of v1 in these. 957 958 - CASE_INSENSITIVE_FS 959 960 Test is run on a case insensitive file system. 961 962 - UTF8_NFD_TO_NFC 963 964 Test is run on a filesystem which converts decomposed utf-8 (nfd) 965 to precomposed utf-8 (nfc). 966 967 - PTHREADS 968 969 Git wasn't compiled with NO_PTHREADS=YesPlease. 970 971Tips for Writing Tests 972---------------------- 973 974As with any programming projects, existing programs are the best 975source of the information. However, do _not_ emulate 976t0000-basic.sh when writing your tests. The test is special in 977that it tries to validate the very core of GIT. For example, it 978knows that there will be 256 subdirectories under .git/objects/, 979and it knows that the object ID of an empty tree is a certain 98040-byte string. This is deliberately done so in t0000-basic.sh 981because the things the very basic core test tries to achieve is 982to serve as a basis for people who are changing the GIT internal 983drastically. For these people, after making certain changes, 984not seeing failures from the basic test _is_ a failure. And 985such drastic changes to the core GIT that even changes these 986otherwise supposedly stable object IDs should be accompanied by 987an update to t0000-basic.sh. 988 989However, other tests that simply rely on basic parts of the core 990GIT working properly should not have that level of intimate 991knowledge of the core GIT internals. If all the test scripts 992hardcoded the object IDs like t0000-basic.sh does, that defeats 993the purpose of t0000-basic.sh, which is to isolate that level of 994validation in one place. Your test also ends up needing 995updating when such a change to the internal happens, so do _not_ 996do it and leave the low level of validation to t0000-basic.sh. 997 998Test coverage 999-------------10001001You can use the coverage tests to find code paths that are not being1002used or properly exercised yet.10031004To do that, run the coverage target at the top-level (not in the t/1005directory):10061007 make coverage10081009That'll compile Git with GCC's coverage arguments, and generate a test1010report with gcov after the tests finish. Running the coverage tests1011can take a while, since running the tests in parallel is incompatible1012with GCC's coverage mode.10131014After the tests have run you can generate a list of untested1015functions:10161017 make coverage-untested-functions10181019You can also generate a detailed per-file HTML report using the1020Devel::Cover module. To install it do:10211022 # On Debian or Ubuntu:1023 sudo aptitude install libdevel-cover-perl10241025 # From the CPAN with cpanminus1026 curl -L http://cpanmin.us | perl - --sudo --self-upgrade1027 cpanm --sudo Devel::Cover10281029Then, at the top-level:10301031 make cover_db_html10321033That'll generate a detailed cover report in the "cover_db_html"1034directory, which you can then copy to a webserver, or inspect locally1035in a browser.