Core Git Tests

==============

This directory holds many test scripts for core Git tools. The

first part of this short document describes how to run the tests

and read their output.

When fixing the tools or adding enhancements, you are strongly

encouraged to add tests in this directory to cover what you are

trying to fix or enhance. The later part of this short document

describes how your test scripts should be organized.

Running Tests

-------------

The easiest way to run tests is to say "make". This runs all

the tests.

*** t0000-basic.sh ***

ok 1 - .git/objects should be empty after git init in an empty repo.

ok 2 - .git/objects should have 3 subdirectories.

ok 3 - success is reported like this

...

ok 43 - very long name in the index handled sanely

# fixed 1 known breakage(s)

# still have 1 known breakage(s)

# passed all remaining 42 test(s)

1..43

*** t0001-init.sh ***

ok 1 - plain

ok 2 - plain with GIT_WORK_TREE

ok 3 - plain bare

t/Makefile defines a target for each test file, such that you can also use

shell pattern matching to run a subset of the tests:

make *checkout*

will run all tests with 'checkout' in their filename.

Since the tests all output TAP (see https://testanything.org) they can

be run with any TAP harness. Here's an example of parallel testing

powered by a recent version of prove(1):

$ prove --timer --jobs 15 ./t[0-9]*.sh

[19:17:33] ./t0005-signals.sh ................................... ok 36 ms

[19:17:33] ./t0022-crlf-rename.sh ............................... ok 69 ms

[19:17:33] ./t0024-crlf-archive.sh .............................. ok 154 ms

[19:17:33] ./t0004-unwritable.sh ................................ ok 289 ms

[19:17:33] ./t0002-gitfile.sh ................................... ok 480 ms

===( 102;0 25/? 6/? 5/? 16/? 1/? 4/? 2/? 1/? 3/? 1... )===

prove and other harnesses come with a lot of useful options. The

--state option in particular is very useful:

# Repeat until no more failures

$ prove -j 15 --state=failed,save ./t[0-9]*.sh

You can give DEFAULT_TEST_TARGET=prove on the make command (or define it

in config.mak) to cause "make test" to run tests under prove.

GIT_PROVE_OPTS can be used to pass additional options, e.g.

$ make DEFAULT_TEST_TARGET=prove GIT_PROVE_OPTS='--timer --jobs 16' test

You can also run each test individually from command line, like this:

$ sh ./t3010-ls-files-killed-modified.sh

ok 1 - git update-index --add to add various paths.

ok 2 - git ls-files -k to show killed files.

ok 3 - validate git ls-files -k output.

ok 4 - git ls-files -m to show modified files.

ok 5 - validate git ls-files -m output.

# passed all 5 test(s)

1..5

You can pass --verbose (or -v), --debug (or -d), and --immediate

(or -i) command line argument to the test, or by setting GIT_TEST_OPTS

appropriately before running "make". Short options can be bundled, i.e.

'-d -v' is the same as '-dv'.

-v::

--verbose::

This makes the test more verbose. Specifically, the

command being run and their output if any are also

output.

--verbose-only=<pattern>::

Like --verbose, but the effect is limited to tests with

numbers matching <pattern>. The number matched against is

simply the running count of the test within the file.

-x::

Turn on shell tracing (i.e., `set -x`) during the tests

themselves. Implies `--verbose`.

Ignored in test scripts that set the variable 'test_untraceable'

to a non-empty value, unless it's run with a Bash version

supporting BASH_XTRACEFD, i.e. v4.1 or later.

-d::

--debug::

This may help the person who is developing a new test.

It causes the command defined with test_debug to run.

The "trash" directory (used to store all temporary data

during testing) is not deleted even if there are no

failed tests so that you can inspect its contents after

the test finished.

-i::

--immediate::

This causes the test to immediately exit upon the first

failed test. Cleanup commands requested with

test_when_finished are not executed if the test failed,

in order to keep the state for inspection by the tester

to diagnose the bug.

-l::

--long-tests::

This causes additional long-running tests to be run (where

available), for more exhaustive testing.

-r::

--run=<test-selector>::

Run only the subset of tests indicated by

<test-selector>. See section "Skipping Tests" below for

<test-selector> syntax.

--valgrind=<tool>::

Execute all Git binaries under valgrind tool <tool> and exit

with status 126 on errors (just like regular tests, this will

only stop the test script when running under -i).

Since it makes no sense to run the tests with --valgrind and

not see any output, this option implies --verbose. For

convenience, it also implies --tee.

<tool> defaults to 'memcheck', just like valgrind itself.

Other particularly useful choices include 'helgrind' and

'drd', but you may use any tool recognized by your valgrind

installation.

As a special case, <tool> can be 'memcheck-fast', which uses

memcheck but disables --track-origins. Use this if you are

running tests in bulk, to see if there are _any_ memory

issues.

Note that memcheck is run with the option --leak-check=no,

as the git process is short-lived and some errors are not

interesting. In order to run a single command under the same

conditions manually, you should set GIT_VALGRIND to point to

the 't/valgrind/' directory and use the commands under

't/valgrind/bin/'.

--valgrind-only=<pattern>::

Like --valgrind, but the effect is limited to tests with

numbers matching <pattern>. The number matched against is

simply the running count of the test within the file.

--tee::

In addition to printing the test output to the terminal,

write it to files named 't/test-results/$TEST_NAME.out'.

As the names depend on the tests' file names, it is safe to

run the tests with this option in parallel.

-V::

--verbose-log::

Write verbose output to the same logfile as `--tee`, but do

_not_ write it to stdout. Unlike `--tee --verbose`, this option

is safe to use when stdout is being consumed by a TAP parser

like `prove`. Implies `--tee` and `--verbose`.

--with-dashes::

By default tests are run without dashed forms of

commands (like git-commit) in the PATH (it only uses

wrappers from ../bin-wrappers). Use this option to include

the build directory (..) in the PATH, which contains all

the dashed forms of commands. This option is currently

implied by other options like --valgrind and

GIT_TEST_INSTALLED.

--no-bin-wrappers::

By default, the test suite uses the wrappers in

`../bin-wrappers/` to execute `git` and friends. With this option,

`../git` and friends are run directly. This is not recommended

in general, as the wrappers contain safeguards to ensure that no

files from an installed Git are used, but can speed up test runs

especially on platforms where running shell scripts is expensive

(most notably, Windows).

--root=<directory>::

Create "trash" directories used to store all temporary data during

testing under <directory>, instead of the t/ directory.

Using this option with a RAM-based filesystem (such as tmpfs)

can massively speed up the test suite.

--chain-lint::

--no-chain-lint::

If --chain-lint is enabled, the test harness will check each

test to make sure that it properly "&&-chains" all commands (so

that a failure in the middle does not go unnoticed by the final

exit code of the test). This check is performed in addition to

running the tests themselves. You may also enable or disable

this feature by setting the GIT_TEST_CHAIN_LINT environment

variable to "1" or "0", respectively.

--stress::

Run the test script repeatedly in multiple parallel jobs until

one of them fails. Useful for reproducing rare failures in

flaky tests. The number of parallel jobs is, in order of

precedence: the value of the GIT_TEST_STRESS_LOAD

environment variable, or twice the number of available

processors (as shown by the 'getconf' utility), or 8.

Implies `--verbose -x --immediate` to get the most information

about the failure. Note that the verbose output of each test

job is saved to 't/test-results/$TEST_NAME.stress-<nr>.out',

and only the output of the failed test job is shown on the

terminal. The names of the trash directories get a

'.stress-<nr>' suffix, and the trash directory of the failed

test job is renamed to end with a '.stress-failed' suffix.

--stress-jobs=<N>::

Override the number of parallel jobs. Implies `--stress`.

--stress-limit=<N>::

When combined with --stress run the test script repeatedly

this many times in each of the parallel jobs or until one of

them fails, whichever comes first. Implies `--stress`.

You can also set the GIT_TEST_INSTALLED environment variable to

the bindir of an existing git installation to test that installation.

You still need to have built this git sandbox, from which various

test-* support programs, templates, and perl libraries are used.

If your installed git is incomplete, it will silently test parts of

your built version instead.

When using GIT_TEST_INSTALLED, you can also set GIT_TEST_EXEC_PATH to

override the location of the dashed-form subcommands (what

GIT_EXEC_PATH would be used for during normal operation).

GIT_TEST_EXEC_PATH defaults to `$GIT_TEST_INSTALLED/git --exec-path`.

Skipping Tests

--------------

In some environments, certain tests have no way of succeeding

due to platform limitation, such as lack of 'unzip' program, or

filesystem that do not allow arbitrary sequence of non-NUL bytes

as pathnames.

You should be able to say something like

$ GIT_SKIP_TESTS=t9200.8 sh ./t9200-git-cvsexport-commit.sh

and even:

$ GIT_SKIP_TESTS='t[0-4]??? t91?? t9200.8' make

to omit such tests. The value of the environment variable is a

SP separated list of patterns that tells which tests to skip,

and either can match the "t[0-9]{4}" part to skip the whole

test, or t[0-9]{4} followed by ".$number" to say which

particular test to skip.

For an individual test suite --run could be used to specify that

only some tests should be run or that some tests should be

excluded from a run.

The argument for --run, <test-selector>, is a list of description

substrings or globs or individual test numbers or ranges with an

optional negation prefix (of '!') that define what tests in a test

suite to include (or exclude, if negated) in the run. A range is two

numbers separated with a dash and specifies an inclusive range of tests

to run. You may omit the first or the second number to

mean "from the first test" or "up to the very last test" respectively.

The argument to --run is split on commas into separate strings,

numbers, and ranges, and picks all tests that match any of the

individual selection criteria. If the substring of the description

text that you want to match includes a comma, use the glob character

'?' instead. For example --run='rebase,merge?cherry-pick' would match

on all tests that match either the glob *rebase* or the glob

*merge?cherry-pick*.

If --run starts with an unprefixed number or range, the initial

set of tests to run is empty. If the first item starts with '!',

all the tests are added to the initial set. After initial set is

determined, every test number or range is added or excluded from

the set one by one, from left to right.

For example, to run only tests up to a specific test (21), one

could do this:

$ sh ./t9200-git-cvsexport-commit.sh --run='1-21'

or this:

$ sh ./t9200-git-cvsexport-commit.sh --run='-21'

Common case is to run several setup tests (1, 2, 3) and then a

specific test (21) that relies on that setup:

$ sh ./t9200-git-cvsexport-commit.sh --run='1,2,3,21'

or:

$ sh ./t9200-git-cvsexport-commit.sh --run=1,2,3,21

or:

$ sh ./t9200-git-cvsexport-commit.sh --run='-3,21'

As noted above, the test set is built by going through the items

from left to right, so this:

$ sh ./t9200-git-cvsexport-commit.sh --run='1-4,!3'

will run tests 1, 2, and 4. Items that come later have higher

precedence. It means that this:

$ sh ./t9200-git-cvsexport-commit.sh --run='!3,1-4'

would just run tests from 1 to 4, including 3.

You may use negation with ranges. The following will run all

test in the test suite except from 7 up to 11:

$ sh ./t9200-git-cvsexport-commit.sh --run='!7-11'

Sometimes there may be multiple tests with e.g. "setup" in their name

that are needed and rather than figuring out the number for all of them

we can just use "setup" as a substring/glob to match against the test

description:

$ sh ./t0050-filesystem.sh --run=setup,9-11

or one could select both the setup tests and the rename ones (assuming all

relevant tests had those words in their descriptions):

$ sh ./t0050-filesystem.sh --run=setup,rename

Some tests in a test suite rely on the previous tests performing

certain actions, specifically some tests are designated as

"setup" test, so you cannot _arbitrarily_ disable one test and

expect the rest to function correctly.

--run is mostly useful when you want to focus on a specific test

and know what setup is needed for it. Or when you want to run

everything up to a certain test.

Running tests with special setups

---------------------------------

The whole test suite could be run to test some special features

that cannot be easily covered by a few specific test cases. These

could be enabled by running the test suite with correct GIT_TEST_

environment set.

GIT_TEST_FAIL_PREREQS=<boolean> fails all prerequisites. This is

useful for discovering issues with the tests where say a later test

implicitly depends on an optional earlier test.

There's a "FAIL_PREREQS" prerequisite that can be used to test for

whether this mode is active, and e.g. skip some tests that are hard to

refactor to deal with it. The "SYMLINKS" prerequisite is currently

excluded as so much relies on it, but this might change in the future.

GIT_TEST_SPLIT_INDEX=<boolean> forces split-index mode on the whole

test suite. Accept any boolean values that are accepted by git-config.

GIT_TEST_PROTOCOL_VERSION=<n>, when set, makes 'protocol.version'

default to n.

GIT_TEST_FULL_IN_PACK_ARRAY=<boolean> exercises the uncommon

pack-objects code path where there are more than 1024 packs even if

the actual number of packs in repository is below this limit. Accept

any boolean values that are accepted by git-config.

GIT_TEST_OE_SIZE=<n> exercises the uncommon pack-objects code path

where we do not cache object size in memory and read it from existing

packs on demand. This normally only happens when the object size is

over 2GB. This variable forces the code path on any object larger than

<n> bytes.

GIT_TEST_OE_DELTA_SIZE=<n> exercises the uncommon pack-objects code

path where deltas larger than this limit require extra memory

allocation for bookkeeping.

GIT_TEST_VALIDATE_INDEX_CACHE_ENTRIES=<boolean> checks that cache-tree

records are valid when the index is written out or after a merge. This

is mostly to catch missing invalidation. Default is true.

GIT_TEST_COMMIT_GRAPH=<boolean>, when true, forces the commit-graph to

be written after every 'git commit' command, and overrides the

'core.commitGraph' setting to true.

GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS=<boolean>, when true, forces

commit-graph write to compute and write changed path Bloom filters for

every 'git commit-graph write', as if the `--changed-paths` option was

passed in.

GIT_TEST_FSMONITOR=$PWD/t7519/fsmonitor-all exercises the fsmonitor

code paths for utilizing a (hook based) file system monitor to speed up

detecting new or changed files.

GIT_TEST_INDEX_VERSION=<n> exercises the index read/write code path

for the index version specified. Can be set to any valid version

(currently 2, 3, or 4).

GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL=<boolean> if enabled will

use the boundary-based bitmap traversal algorithm. See the documentation

of `pack.useBitmapBoundaryTraversal` for more details.

GIT_TEST_PACK_SPARSE=<boolean> if disabled will default the pack-objects

builtin to use the non-sparse object walk. This can still be overridden by

the --sparse command-line argument.

GIT_TEST_PACK_PATH_WALK=<boolean> if enabled will default the pack-objects

builtin to use the path-walk API for the object walk. This can still be

overridden by the --no-path-walk command-line argument.

GIT_TEST_PRELOAD_INDEX=<boolean> exercises the preload-index code path

by overriding the minimum number of cache entries required per thread.

GIT_TEST_INDEX_THREADS=<n> enables exercising the multi-threaded loading

of the index for the whole test suite by bypassing the default number of

cache entries and thread minimums. Setting this to 1 will make the

index loading single threaded.

GIT_TEST_MULTI_PACK_INDEX=<boolean>, when true, forces the multi-pack-

index to be written after every 'git repack' command, and overrides the

'core.multiPackIndex' setting to true.

GIT_TEST_MULTI_PACK_INDEX_WRITE_INCREMENTAL=<boolean>, when true, sets

the '--incremental' option on all invocations of 'git multi-pack-index

write'.

GIT_TEST_SIDEBAND_ALL=<boolean>, when true, overrides the

'uploadpack.allowSidebandAll' setting to true, and when false, forces

fetch-pack to not request sideband-all (even if the server advertises

sideband-all).

GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS=<boolean>, when true (which is

the default when running tests), errors out when an abbreviated option

is used.

GIT_TEST_DEFAULT_HASH=<hash-algo> specifies which hash algorithm to

use in the test scripts. Recognized values for <hash-algo> are "sha1"

and "sha256".

GIT_TEST_DEFAULT_REF_STORAGE_FORMAT=<format> specifies which ref storage format

to use in the test scripts. Recognized values for <format> are "files" and

"reftable".

GIT_TEST_NO_WRITE_REV_INDEX=<boolean>, when true disables the

'pack.writeReverseIndex' setting.

GIT_TEST_SPARSE_INDEX=<boolean>, when true enables index writes to use the

sparse-index format by default.

GIT_TEST_CHECKOUT_WORKERS=<n> overrides the 'checkout.workers' setting

to <n> and 'checkout.thresholdForParallelism' to 0, forcing the

execution of the parallel-checkout code.

GIT_TEST_REQUIRE_PREREQ=<list> allows specifying a space separated list of

prereqs that are required to succeed. If a prereq in this list is triggered by

a test and then fails then the whole test run will abort. This can help to make

sure the expected tests are executed and not silently skipped when their

dependency breaks or is simply not present in a new environment.

GIT_TEST_NAME_HASH_VERSION=<int>, when set, causes 'git pack-objects' to

assume '--name-hash-version=<n>'.

Naming Tests

------------

The test files are named as:

tNNNN-commandname-details.sh

where N is a decimal digit.

First digit tells the family:

0 - the absolute basics and global stuff

1 - the basic commands concerning database

2 - the basic commands concerning the working tree

3 - the other basic commands (e.g. ls-files)

4 - the diff commands

5 - the pull and exporting commands

6 - the revision tree commands (even e.g. merge-base)

7 - the porcelainish commands concerning the working tree

8 - the porcelainish commands concerning forensics

9 - the git tools

Second digit tells the particular command we are testing.

Third digit (optionally) tells the particular switch or group of switches

we are testing.

If you create files under t/ directory (i.e. here) that is not

the top-level test script, never name the file to match the above

pattern. The Makefile here considers all such files as the

top-level test script and tries to run all of them. Care is

especially needed if you are creating a common test library

file, similar to test-lib.sh, because such a library file may

not be suitable for standalone execution.

Writing Tests

-------------

The test script is written as a shell script. It should start

with the standard "#!/bin/sh", and an

assignment to variable 'test_description', like this:

#!/bin/sh

test_description='xxx test (option --frotz)

This test registers the following structure in the cache

and tries to run git-ls-files with option --frotz.'

Source 'test-lib.sh'

--------------------

After assigning test_description, the test script should source

test-lib.sh like this:

. ./test-lib.sh

This test harness library does the following things:

- If the script is invoked with command line argument --help

(or -h), it shows the test_description and exits.

- Creates an empty test directory with an empty .git/objects database

and chdir(2) into it. This directory is 't/trash

directory.$test_name_without_dotsh', with t/ subject to change by

the --root option documented above, and a '.stress-<N>' suffix

appended by the --stress option.

- Defines standard test helper functions for your scripts to

use. These functions are designed to make all scripts behave

consistently when command line arguments --verbose (or -v),

--debug (or -d), and --immediate (or -i) is given.

Recommended style

-----------------

- Keep the test_expect_* function call and test title on

the same line.

For example, with test_expect_success, write it like:

test_expect_success 'test title' '

... test body ...

'

Instead of:

test_expect_success \

'test title' \

'... test body ...'

- End the line with an opening single quote.

- Indent here-document bodies, and use "<<-" instead of "<<"

to strip leading TABs used for indentation:

test_expect_success 'test something' '

cat >expect <<-\EOF &&

one

two

three

EOF

test_something > actual &&

test_cmp expect actual

'

Instead of:

test_expect_success 'test something' '

cat >expect <<\EOF &&

one

two

three

EOF

test_something > actual &&

test_cmp expect actual

'

- Quote or escape the EOF delimiter that begins a here-document if

there is no parameter or other expansion in it, to signal readers

that they can skim it more casually:

cmd <<-\EOF

literal here-document text without any expansion

EOF

Do's & don'ts

-------------

Here are a few examples of things you probably should and shouldn't do

when writing tests.

The "do's:"

- Put all code inside test_expect_success and other assertions.

Even code that isn't a test per se, but merely some setup code

should be inside a test assertion.

- Chain your test assertions

Write test code like this:

git merge foo &&

git push bar &&

test ...

Instead of:

git merge hla

git push gh

test ...

That way all of the commands in your tests will succeed or fail. If

you must ignore the return value of something, consider using a

helper function (e.g. use sane_unset instead of unset, in order

to avoid unportable return value for unsetting a variable that was

already unset), or prepending the command with test_might_fail or

test_must_fail.

- Check the test coverage for your tests. See the "Test coverage"

below.

Don't blindly follow test coverage metrics; if a new function you added

doesn't have any coverage, then you're probably doing something wrong,

but having 100% coverage doesn't necessarily mean that you tested

everything.

Tests that are likely to smoke out future regressions are better

than tests that just inflate the coverage metrics.

- When a test checks for an absolute path that a git command generated,

construct the expected value using $(pwd) rather than $PWD,

$TEST_DIRECTORY, or $TRASH_DIRECTORY. It makes a difference on

Windows, where the shell (MSYS bash) mangles absolute path names.

For details, see the commit message of 4114156ae9.

- Remember that inside the <script> part, the standard output and

standard error streams are discarded, and the test harness only

reports "ok" or "not ok" to the end user running the tests. Under

--verbose, they are shown to help debug the tests.

- Be careful when you loop

You may need to verify multiple things in a loop, but the

following does not work correctly:

test_expect_success 'test three things' '

for i in one two three

do

test_something "$i"

done &&

test_something_else

'

Because the status of the loop itself is the exit status of the

test_something in the last round, the loop does not fail when

"test_something" for "one" or "two" fails. This is not what you

want.

Instead, you can break out of the loop immediately when you see a

failure. Because all test_expect_* snippets are executed inside

a function, "return 1" can be used to fail the test immediately

upon a failure:

test_expect_success 'test three things' '

for i in one two three

do

test_something "$i" || return 1

done &&

test_something_else

'

Note that we still &&-chain the loop to propagate failures from

earlier commands.

- Repeat tests with slightly different arguments in a loop.

In some cases it may make sense to re-run the same set of tests with

different options or commands to ensure that the command behaves

despite the different parameters. This can be achieved by looping

around a specific parameter:

for arg in '' "--foo"

do

test_expect_success "test command ${arg:-without arguments}" '

command $arg

'

done

Note that while the test title uses double quotes ("), the test body

should continue to use single quotes (') to avoid breakage in case the

values contain e.g. quoting characters. The loop variable will be

accessible regardless of the single quotes as the test body is passed

to `eval`.

And here are the "don'ts:"

- Don't exit() within a <script> part.

The harness will catch this as a programming error of the test.

Use test_done instead if you need to stop the tests early (see

"Skipping tests" below).

- Don't use '! git cmd' when you want to make sure the git command

exits with failure in a controlled way by calling "die()". Instead,

use 'test_must_fail git cmd'. This will signal a failure if git

dies in an unexpected way (e.g. segfault).

On the other hand, don't use test_must_fail for running regular

platform commands; just use '! cmd'. We are not in the business

of verifying that the world given to us sanely works.

- Don't feed the output of a git command to a pipe, as in:

git -C repo ls-files |

xargs -n 1 basename |

grep foo

which will discard git's exit code and may mask a crash. In the

above example, all exit codes are ignored except grep's.

Instead, write the output of that command to a temporary

file with ">" or assign it to a variable with "x=$(git ...)" rather

than pipe it.

- Don't use command substitution in a way that discards git's exit

code. When assigning to a variable, the exit code is not discarded,

e.g.:

x=$(git cat-file -p $sha) &&

...

is OK because a crash in "git cat-file" will cause the "&&" chain

to fail, but:

test "refs/heads/foo" = "$(git symbolic-ref HEAD)"

is not OK and a crash in git could go undetected.

- Don't use perl without spelling it as "$PERL_PATH". This is to help

our friends on Windows where the platform Perl often adds CR before

the end of line, and they bundle Git with a version of Perl that

does not do so, whose path is specified with $PERL_PATH. Note that we

provide a "perl" function which uses $PERL_PATH under the hood, so

you do not need to worry when simply running perl in the test scripts

(but you do, for example, on a shebang line or in a sub script

created via "write_script").

- Don't use sh without spelling it as "$SHELL_PATH", when the script

can be misinterpreted by broken platform shell (e.g. Solaris).

- Don't chdir around in tests. It is not sufficient to chdir to

somewhere and then chdir back to the original location later in

the test, as any intermediate step can fail and abort the test,

causing the next test to start in an unexpected directory. Do so

inside a subshell if necessary.

- Don't save and verify the standard error of compound commands, i.e.

group commands, subshells, and shell functions (except test helper

functions like 'test_must_fail') like this:

( cd dir && git cmd ) 2>error &&

test_cmp expect error

When running the test with '-x' tracing, then the trace of commands

executed in the compound command will be included in standard error

as well, quite possibly throwing off the subsequent checks examining

the output. Instead, save only the relevant git command's standard

error:

( cd dir && git cmd 2>../error ) &&

test_cmp expect error

- Don't break the TAP output

The raw output from your test may be interpreted by a TAP harness. TAP

harnesses will ignore everything they don't know about, but don't step

on their toes in these areas:

- Don't print lines like "$x..$y" where $x and $y are integers.

- Don't print lines that begin with "ok" or "not ok".

TAP harnesses expect a line that begins with either "ok" and "not

ok" to signal a test passed or failed (and our harness already

produces such lines), so your script shouldn't emit such lines to

their output.

You can glean some further possible issues from the TAP grammar

(see https://metacpan.org/pod/TAP::Parser::Grammar#TAP-GRAMMAR)

but the best indication is to just run the tests with prove(1),

it'll complain if anything is amiss.

Skipping tests

--------------

If you need to skip tests you should do so by using the three-arg form

of the test_expect_* functions (see the "Test harness library" section

below), e.g.:

test_expect_success PERL 'I need Perl' '

perl -e "hlagh() if unf_unf()"

'

The advantage of skipping tests like this is that platforms that don't

have the PERL and other optional dependencies get an indication of how

many tests they're missing.

If the test code is too hairy for that (i.e. does a lot of setup work

outside test assertions) you can also skip all remaining tests by

setting skip_all and immediately call test_done:

if ! test_have_prereq PERL

then

skip_all='skipping perl interface tests, perl not available'

test_done

fi

The string you give to skip_all will be used as an explanation for why

the test was skipped.

End with test_done

------------------

Your script will be a sequence of tests, using helper functions

from the test harness library. At the end of the script, call

'test_done'.

Test harness library

--------------------

There are a handful helper functions defined in the test harness

library for your script to use. Some of them are listed below;

see test-lib-functions.sh for the full list and their options.

- test_expect_success [<prereq>] <message> <script>

Usually takes two strings as parameters, and evaluates the

<script>. If it yields success, test is considered

successful. <message> should state what it is testing.

Example:

test_expect_success \

'git-write-tree should be able to write an empty tree.' \

'tree=$(git-write-tree)'

If <script> is `-` (a single dash), then the script to run is read

from stdin. This lets you more easily use single quotes within the

script by using a here-doc. For example:

test_expect_success 'output contains expected string' - <<\EOT

grep "this string has 'quotes' in it" output

EOT

If you supply three parameters the first will be taken to be a

prerequisite; see the test_set_prereq and test_have_prereq

documentation below:

test_expect_success TTY 'git --paginate rev-list uses a pager' \

' ... '

You can also supply a comma-separated list of prerequisites, in the

rare case where your test depends on more than one:

test_expect_success PERL,PYTHON 'yo dawg' \

' test $(perl -E '\''print eval "1 +" . qx[python -c "print(2)"]'\'') = "4" '

- test_expect_failure [<prereq>] <message> <script>

This is NOT the opposite of test_expect_success, but is used

to mark a test that demonstrates a known breakage. Unlike

the usual test_expect_success tests, which say "ok" on

success and "FAIL" on failure, this will say "FIXED" on

success and "still broken" on failure. Failures from these

tests won't cause -i (immediate) to stop.

Like test_expect_success this function can optionally use a three

argument invocation with a prerequisite as the first argument.

- test_debug <script>

This takes a single argument, <script>, and evaluates it only

when the test script is started with --debug command line

argument. This is primarily meant for use during the

development of a new test script.

- debug [options] <git-command>

Run a git command inside a debugger. This is primarily meant for

use when debugging a failing test script. With '-t', use your

original TERM instead of test-lib.sh's "dumb", so that your

debugger interface has colors.

- test_done

Your test script must have test_done at the end. Its purpose

is to summarize successes and failures in the test script and

exit with an appropriate error code.

- test_tick

Make commit and tag names consistent by setting the author and

committer times to defined state. Subsequent calls will

advance the times by a fixed amount.

- test_commit <message> [<filename> [<contents>]]

Creates a commit with the given message, committing the given

file with the given contents (default for both is to reuse the

message string), and adds a tag (again reusing the message

string as name). Calls test_tick to make the SHA-1s

reproducible.

- test_merge <message> <commit-or-tag>

Merges the given rev using the given message. Like test_commit,

creates a tag and calls test_tick before committing.

- commit_body <rev>

Print the message body of <rev>, i.e. the contents of its commit

object with the header removed. Use this instead of piping

"git cat-file commit" into "sed", which would hide a failure of

the git command.

Example:

commit_body HEAD >actual

- test_set_prereq <prereq>

Set a test prerequisite to be used later with test_have_prereq. The

test-lib will set some prerequisites for you, see the

"Prerequisites" section below for a full list of these.

Others you can set yourself and use later with either

test_have_prereq directly, or the three argument invocation of

test_expect_success and test_expect_failure.

- test_have_prereq <prereq>

Check if we have a prerequisite previously set with test_set_prereq.

The most common way to use this explicitly (as opposed to the

implicit use when an argument is passed to test_expect_*) is to skip

all the tests at the start of the test script if we don't have some

essential prerequisite:

if ! test_have_prereq PERL

then

skip_all='skipping perl interface tests, perl not available'

test_done

fi

- test_lazy_prereq <prereq> <script>

Declare the way to determine if a test prerequisite <prereq> is

satisfied or not, but delay the actual determination until the

prerequisite is actually used by "test_have_prereq" or the

three-arg form of the test_expect_* functions. For example, this

is how the SYMLINKS prerequisite is declared to see if the platform

supports symbolic links:

test_lazy_prereq SYMLINKS '

ln -s x y && test -h y

'

The script is lazily invoked when SYMLINKS prerequisite is first

queried by either "test_have_prereq SYMLINKS" or "test_expect_*

SYMLINKS ...". The script is run in a temporary directory inside

a subshell, so you do not have to worry about removing temporary

files you create there. When the script exits with status 0, the

prerequisite is set. Exiting with non-zero status other than 125

makes the prerequisite unsatisified. Exiting the script with 125

signals a programming error and is used to mark a prerequisite that

should not be used by test scripts.

- test_expect_code <exit-code> <command>