A new extension to the index file has been introduced, which allows
the file to be read in parallel.
* bp/read-cache-parallel:
read-cache: load cache entries on worker threads
ieot: add Index Entry Offset Table (IEOT) extension
read-cache: load cache extensions on a worker thread
config: add new index.threads config setting
eoie: add End of Index Entry (EOIE) extension
read-cache: clean up casting and byte decoding
read-cache.c: optimize reading index format v4
Some environment variables that control the runtime options of Git
used during tests are getting renamed for consistency.
* bp/rename-test-env-var:
t0000: do not get self-test disrupted by environment warnings
preload-index: update GIT_FORCE_PRELOAD_TEST support
read-cache: update TEST_GIT_INDEX_VERSION support
fsmonitor: update GIT_TEST_FSMONITOR support
preload-index: use git_env_bool() not getenv() for customization
t/README: correct spelling of "uncommon"
Various test scripts have been updated for style and also correct
handling of exit status of various commands.
* md/test-cleanup:
tests: order arguments to git-rev-list properly
t9109: don't swallow Git errors upstream of pipes
tests: don't swallow Git errors upstream of pipes
t/*: fix ordering of expected/observed arguments
tests: standardize pipe placement
Documentation: add shell guidelines
t/README: reformat Do, Don't, Keep in mind lists
Add support for a new index.threads config setting which will be used to
control the threading code in do_read_index(). A value of 0 will tell the
index code to automatically determine the correct number of threads to use.
A value of 1 will make the code single threaded. A value greater than 1
will set the maximum number of threads to use.
For testing purposes, this setting can be overwritten by setting the
GIT_TEST_INDEX_THREADS=<n> environment variable to a value greater than 0.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Various tests have been updated to make it easier to swap the
hash function used for object identification.
* bc/hash-independent-tests:
t5318: use test_oid for HASH_LEN
t1407: make hash size independent
t1406: make hash-size independent
t1405: make hash size independent
t1400: switch hard-coded object ID to variable
t1006: make hash size independent
t0064: make hash size independent
t0002: abstract away SHA-1 specific constants
t0000: update tests for SHA-256
t0000: use hash translation table
t: add test functions to translate hash-related values
Add the following guideline to Documentation/CodingGuidelines:
Break overlong lines after "&&", "||", and "|", not before
them; that way the command can continue to subsequent lines
without backslash at the end.
And the following to t/README (since it is specific to writing tests):
Pipes and $(git ...) should be avoided when they swallow exit
codes of Git processes
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The list of Don'ts for test writing has grown large such that it is hard
to see at a glance which section an item is in. In other words, if I
ignore a little bit of surrounding context, the "don'ts" look like
"do's."
To make the list more readable, prefix "Don't" in front of every first
sentence in the items.
Also, the "Keep in mind" list is out of place and awkward, because it
was a very short "list" beneath two very long ones, and it seemed easy
to miss under the list of "don'ts," and it only had one item. So move
this item to the list of "do's" and phrase as "Remember..."
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename GIT_FORCE_PRELOAD_TEST to GIT_TEST_PRELOAD_INDEX for consistency with
the other GIT_TEST_ special setups and properly document its use.
Add logic in t/test-lib.sh to give a warning when the old variable is set to
let people know they need to update their environment to use the new
variable.
Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename TEST_GIT_INDEX_VERSION to GIT_TEST_INDEX_VERSION for consistency with
the other GIT_TEST_ special setups and properly document its use.
Add logic in t/test-lib.sh to give a warning when the old variable is set to
let people know they need to update their environment to use the new
variable.
Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename GIT_FSMONITOR_TEST to GIT_TEST_FSMONITOR for consistency with the
other GIT_TEST_ special setups and properly document its use.
Add logic in t/test-lib.sh to give a warning when the old variable is set to
let people know they need to update their environment to use the new
variable.
Remove the outdated instructions on how to run the test suite utilizing
fsmonitor now that it is properly documented in t/README.
Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Correct a spelling error in the documentation for GIT_TEST_OE_DELTA_SIZE.
Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The unpack_trees() API used in checking out a branch and merging
walks one or more trees along with the index. When the cache-tree
in the index tells us that we are walking a tree whose flattened
contents is known (i.e. matches a span in the index), as linearly
scanning a span in the index is much more efficient than having to
open tree objects recursively and listing their entries, the walk
can be optimized, which is done in this topic.
* nd/unpack-trees-with-cache-tree:
Document update for nd/unpack-trees-with-cache-tree
cache-tree: verify valid cache-tree in the test suite
unpack-trees: add missing cache invalidation
unpack-trees: reuse (still valid) cache-tree from src_index
unpack-trees: reduce malloc in cache-tree walk
unpack-trees: optimize walking same trees with cache-tree
unpack-trees: add performance tracing
trace.h: support nested performance tracing
Add several test functions to make working with various hash-related
values easier.
Add test_oid_init, which loads common hash-related constants and
placeholder object IDs from the newly added files in t/oid-info.
Provide values for these constants for both SHA-1 and SHA-256.
Add test_oid_cache, which accepts data on standard input in the form of
hash-specific key-value pairs that can be looked up later, using the
same format as the files in t/oid-info. Document this format in a
t/oid-info/README directory so that it's easier to use in the future.
Add test_oid, which is used to specify look up a per-hash value
(produced on standard output) based on the key specified as its
argument. Usually the data to be looked up will be a hash-related
constant (such as the size of the hash in binary or hexadecimal), a
well-known or placeholder object ID (such as the all-zeros object ID or
one consisting of "deadbeef" repeated), or something similar. For these
reasons, test_oid will usually be used within a command substitution.
Consequently, redirect the error output to standard error, since
otherwise it will not be displayed.
Add test_detect_hash, which currently only detects SHA-1, and
test_set_hash, which can be used to set a different hash algorithm for
test purposes. In the future, test_detect_hash will learn to actually
detect the hash depending on how the testsuite is to be run.
Use the local keyword within these functions to avoid overwriting other
shell variables. We have had a test balloon in place for a couple of
releases to catch shells that don't have this keyword and have not
received any reports of failure. Note that the varying usages of local
used here are supported by all common open-source shells supporting the
local keyword.
Test these new functions as part of t0000, which also serves to
demonstrate basic usage of them. In addition, add documentation on how
to format the lookup data and how to use the test functions.
Implement two basic lookup charts, one for common invalid or synthesized
object IDs, and one for various facts about the hash function in use.
Provide versions of the data for both SHA-1 and SHA-256.
Since we use shell variables for storage, names used for lookup can
currently consist only of shell identifier characters. If this is a
problem in the future, we can hash the names before use.
Improved-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The commit-graph feature is tested in isolation by
t5318-commit-graph.sh and t6600-test-reach.sh, but there are many
more interesting scenarios involving commit walks. Many of these
scenarios are covered by the existing test suite, but we need to
maintain coverage when the optional commit-graph structure is not
present.
To allow running the full test suite with the commit-graph present,
add a new test environment variable, GIT_TEST_COMMIT_GRAPH. Similar
to GIT_TEST_SPLIT_INDEX, this variable makes every Git command try
to load the commit-graph when parsing commits, and writes the
commit-graph file after every 'git commit' command.
There are a few tests that rely on commits not existing in
pack-files to trigger important events, so manually set
GIT_TEST_COMMIT_GRAPH to false for the necessary commands.
There is one test in t6024-recursive-merge.sh that relies on the
merge-base algorithm picking one of two ambiguous merge-bases, and
the commit-graph feature changes which merge-base is picked.
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix an incorrect comment in the new code added in b4da37380b
(unpack-trees: optimize walking same trees with cache-tree -
2018-08-18) and document about the new test variable that is enabled
by default in test-lib.sh in 4592e6080f (cache-tree: verify valid
cache-tree in the test suite - 2018-08-18)
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Let's start with some background about oe_delta_size() and
oe_set_delta_size(). If you already know, skip the next paragraph.
These two are added in 0aca34e826 (pack-objects: shrink delta_size
field in struct object_entry - 2018-04-14) to help reduce 'struct
object_entry' size. The delta size field in this struct is reduced to
only contain max 1MB. So if any new delta is produced and larger than
1MB, it's dropped because we can't really save such a large size
anywhere. Fallback is provided in case existing packfiles already have
large deltas, then we can retrieve it from the pack.
While this should help small machines repacking large repos without
large deltas (i.e. less memory pressure), dropping large deltas during
the delta selection process could end up with worse pack files. And if
existing packfiles already have >1MB delta and pack-objects is
instructed to not reuse deltas, all of them will be dropped on the
floor, and the resulting pack would be definitely bigger.
There is also a regression in terms of CPU/IO if we have large on-disk
deltas because fallback code needs to parse the pack every time the
delta size is needed and just access to the mmap'd pack data is enough
for extra page faults when memory is under pressure.
Both of these issues were reported on the mailing list. Here's some
numbers for comparison.
Version Pack (MB) MaxRSS(kB) Time (s)
------- --------- ---------- --------
2.17.0 5498 43513628 2494.85
2.18.0 10531 40449596 4168.94
This patch provides a better fallback that is
- cheaper in terms of cpu and io because we won't have to read
existing pack files as much
- better in terms of pack size because the pack heuristics is back to
2.17.0 time, we do not drop large deltas at all
If we encounter any delta (on-disk or created during try_delta phase)
that is larger than the 1MB limit, we stop using delta_size_ field for
this because it can't contain such size anyway. A new array of delta
size is dynamically allocated and can hold all the deltas that 2.17.0
can. This array only contains delta sizes that delta_size_ can't
contain.
With this, we do not have to drop deltas in try_delta() anymore. Of
course the downside is we use slightly more memory, even compared to
2.17.0. But since this is considered an uncommon case, a bit more
memory consumption should not be a problem.
Delta size limit is also raised from 1MB to 16MB to better cover
common case and avoid that extra memory consumption (99.999% deltas in
this reported repo are under 12MB; Jeff noted binary artifacts topped
out at about 3MB in some other private repos). Other fields are
shuffled around to keep this struct packed tight. We don't use more
memory in common case even with this limit update.
A note about thread synchronization. Since this code can be run in
parallel during delta searching phase, we need a mutex. The realloc
part in packlist_alloc() is not protected because it only happens
during the object counting phase, which is always single-threaded.
Access to e->delta_size_ (and by extension
pack->delta_size[e - pack->objects]) is unprotected as before, the
thread scheduler in pack-objects must make sure "e" is never updated
by two different threads.
The area under the new lock is as small as possible, avoiding locking
at all in common case, since lock contention with high thread count
could be expensive (most blobs are small enough that delta compute
time is short and we end up taking the lock very often). The previous
attempt to always hold a lock in oe_delta_size() and
oe_set_delta_size() increases execution time by 33% when repacking
linux.git with with 40 threads.
Reported-by: Elijah Newren <newren@gmail.com>
Helped-by: Elijah Newren <newren@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's very very rare that an uncompressed object is larger than 4GB
(partly because Git does not handle those large files very well to
begin with). Let's optimize it for the common case where object size
is smaller than this limit.
Shrink size field down to 31 bits and one overflow bit. If the size is
too large, we read it back from disk. As noted in the previous patch,
we need to return the delta size instead of canonical size when the
to-be-reused object entry type is a delta instead of a canonical one.
Add two compare helpers that can take advantage of the overflow
bit (e.g. if the file is 4GB+, chances are it's already larger than
core.bigFileThreshold and there's no point in comparing the actual
value).
Another note about oe_get_size_slow(). This function MUST be thread
safe because SIZE() macro is used inside try_delta() which may run in
parallel. Outside parallel code, no-contention locking should be dirt
cheap (or insignificant compared to i/o access anyway). To exercise
this code, it's best to run the test suite with something like
make test GIT_TEST_OE_SIZE=4
which forces this code on all objects larger than 3 bytes.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of using 8 bytes (on 64 bit arch) to store a pointer to a
pack. Use an index instead since the number of packs should be
relatively small.
This limits the number of packs we can handle to 1k. Since we can't be
sure people can never run into the situation where they have more than
1k pack files. Provide a fall back route for it.
If we find out they have too many packs, the new in_pack_by_idx[]
array (which has at most 1k elements) will not be used. Instead we
allocate in_pack[] array that holds nr_objects elements. This is
similar to how the optional in_pack_pos field is handled.
The new simple test is just to make sure the too-many-packs code path
is at least executed. The true test is running
make test GIT_TEST_FULL_IN_PACK_ARRAY=1
to take advantage of other special case tests.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While at there, document about this special mode when running the test
suite.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Running test scripts under -x option of the shell is often not a
useful way to debug them, because the error messages from the
commands tests try to capture and inspect are contaminated by the
tracing output by the shell. An earlier work done to make it more
pleasant to run tests under -x with recent versions of bash is
extended to cover posix shells that do not support BASH_XTRACEFD.
* sg/test-x:
travis-ci: run tests with '-x' tracing
t/README: add a note about don't saving stderr of compound commands
t1510-repo-setup: mark as untraceable with '-x'
t9903-bash-prompt: don't check the stderr of __git_ps1()
t5570-git-daemon: don't check the stderr of a subshell
t5526: use $TRASH_DIRECTORY to specify the path of GIT_TRACE log file
t5500-fetch-pack: don't check the stderr of a subshell
t3030-merge-recursive: don't check the stderr of a subshell
t1507-rev-parse-upstream: don't check the stderr of a shell function
t: add means to disable '-x' tracing for individual test scripts
t: prevent '-x' tracing from interfering with test helpers' stderr
Explain in 't/README' why it is a bad idea to redirect and verify the
stderr of compound commands, in the hope that future contributions
will follow this advice and the test suite will keep working with '-x'
tracing and /bin/sh.
While at it, since we can now run the test suite with '-x' without
needing a Bash version supporting BASH_XTRACEFD, remove the now
outdated caution note about non-Bash shells from the description of
the '-x' option.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous patch resolved most of the test failures caused by
running our test suite with '-x' tracing and /bin/sh, and the
following patches in this series will resolve almost all of the
remaining failures. Unfortunately, not yet all.
Add means to disable '-x' tracing for individual test scripts by
setting the $test_untraceable variable to a non-empty value in the
test script before sourcing 'test-lib.sh'. However, since '-x'
tracing is not an issue with recent Bash versions supporting
BASH_XTRACEFD, i.e. v4.1 and later, don't disable tracing when the
test script is run with such a Bash version even when
$test_untraceable is set.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 'test_might_fail' is implemented as a thin wrapper around
'test_must_fail', it also accepts the same options. Mention this in
the docs as well.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
test_cmp_rev is a useful function that's used in quite a few test
scripts. It is however not documented in t/README. Document it.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We generally no longer include copyright notices in new test scripts.
However t/README still mentions it as something to include at the top of
every new script.
Remove that mention as it's outdated.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add LIBPCRE1 and LIBPCRE2 prerequisites which are true when git is
compiled with USE_LIBPCRE1=YesPlease or USE_LIBPCRE2=YesPlease,
respectively.
The syntax of PCRE1 and PCRE2 isn't the same in all cases (see
pcresyntax(3) and pcre2syntax(3)). If test are added that test for
those they'll need to be guarded by these new prerequisites.
The subsequent patch will make use of LIBPCRE2, so LIBPCRE1 isn't
strictly needed for now, but let's add it for consistency and so that
checking for it doesn't have to be done with the less obvious "PCRE,
!LIBPCRE2", which while semantically the same is more confusing, and
would lead to bugs if PCRE v3 is ever released as the tests would mean
v1, not any non-v2 version.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a PTHREADS prerequisite which is false when git is compiled with
NO_PTHREADS=YesPlease.
There's lots of custom code that runs when threading isn't available,
but before this prerequisite there was no way to test it.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename the LIBPCRE prerequisite to PCRE. This is for preparation for
libpcre2 support, where having just "LIBPCRE" would be confusing as it
implies v1 of the library.
None of these tests are incompatible between versions 1 & 2 of
libpcre, it's less confusing to give them a more general name to make
it clear that they work on both library versions.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Clarify the test_have_prereq documentation so that it's clear in the
reader's mind when the text says "most common use of this directly"
what the answer to "as opposed to what?" is.
Usually this function isn't used in lieu of using the prerequisite
support built into test_expect_*, mention that explicitly.
This changes documentation that I added in commit
9a897893a7 ("t/README: Document the prereq functions, and 3-arg
test_*", 2010-07-02).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the mention of "Inside the <script> part, the standard
output..." to use the definite article, which makes more sense in this
context.
This changes documentation I originally added back in commit
20873f45e7 ("t/README: Document the do's and don'ts of tests",
2010-07-02).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change a link to the web version of the TAP::Parser::Grammar
documentation to link to metacpan.org instead of search.cpan.org.
This is something I added back in commit 20873f45e7 ("t/README:
Document the do's and don'ts of tests", 2010-07-02), at the time
search.cpan.org was the more actively maintained CPAN web-interface,
nowadays that's metacpan.org.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The Travis CI configuration we ship ran the tests with --verbose
option but this risks non-TAP output that happens to be "ok" to be
misinterpreted as TAP signalling a test that passed. This resulted
in unnecessary failure. This has been corrected by introducing a
new mode to run our tests in the test harness to send the verbose
output separately to the log file.
* jk/tap-verbose-fix:
test-lib: bail out when "-v" used under "prove"
travis: use --verbose-log test option
test-lib: add --verbose-log option
test-lib: handle TEST_OUTPUT_DIRECTORY with spaces
The "--verbose" option redirects output from arbitrary
test commands to stdout. This is useful for examining the
output manually, like:
./t5547-push-quarantine.sh -v | less
But it also means that the output is intermingled with the
TAP directives, which can confuse a TAP parser like "prove".
This has always been a potential problem, but became an
issue recently when one test happened to output the word
"ok" on a line by itself, which prove interprets as a test
success:
$ prove t5547-push-quarantine.sh :: -v
t5547-push-quarantine.sh .. 1/? To dest.git
* [new branch] HEAD -> master
To dest.git
! [remote rejected] reject -> reject (pre-receive hook declined)
error: failed to push some refs to 'dest.git'
fatal: git cat-file d08c8eba97f4e683ece08654c7c8d2ba0c03b129: bad file
t5547-push-quarantine.sh .. Failed -1/4 subtests
Test Summary Report
-------------------
t5547-push-quarantine.sh (Wstat: 0 Tests: 5 Failed: 0)
Parse errors: Tests out of sequence. Found (2) but expected (3)
Tests out of sequence. Found (3) but expected (4)
Tests out of sequence. Found (4) but expected (5)
Bad plan. You planned 4 tests but ran 5.
Files=1, Tests=5, 0 wallclock secs ( 0.01 usr + 0.01 sys = 0.02 CPU)
Result: FAIL
One answer is "if it hurts, don't do it", but that's not
quite the whole story. The Travis tests use "--verbose
--tee" so that they can get the benefit of prove's parallel
options, along with a verbose log in case there is a
failure. We just need the verbose output to go to the log,
but keep stdout clean.
Getting this right turns out to be surprisingly difficult.
Here's the progression of alternatives I considered:
1. Add an option to write verbose output to stderr. This is
hard to capture, though, because we want each test to
have its own log (because they're all run in parallel
and the jumbled output would be useless).
2. Add an option to write verbose output to a file in
test-results. This works, but the log is missing all of
the non-verbose output, which gives context.
3. Like (2), but teach say_color() to additionally output
to the log. This mostly works, but misses any output
that happens outside of the say() functions (which isn't
a lot, but is a potential maintenance headache).
4. Like (2), but make the log file the same as the "--tee"
file. That almost works, but now we have two processes
opening the same file. That gives us two separate
descriptors, each with their own idea of the current
position. They'll each start writing at offset 0, and
overwrite each other's data.
5. Like (4), but in each case open the file for appending.
That atomically positions each write at the end of the
file.
It's possible we may still get sheared writes between
the two processes, but this is already the case when
writing to stdout. It's not a problem in practice
because the test harness generally waits for snippets to
finish before writing the TAP output.
We can ignore buffering issues with tee, because POSIX
mandates that it does not buffer. Likewise, POSIX
specifies "tee -a", so it should be available
everywhere.
This patch implements option (5), which seems to work well
in practice.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Running tests with '-x' option to trace the individual command
executions is a useful way to debug test scripts, but some tests
that capture the standard error stream and check what the command
said can be broken with the trace output mixed in. When running
our tests under "bash", however, we can redirect the trace output
to another file descriptor to keep the standard error of programs
being tested intact.
* jk/test-send-sh-x-trace-elsewhere:
test-lib: set BASH_XTRACEFD automatically
Running tests with '-x' option to trace the individual command
executions is a useful way to debug test scripts, but some tests
that capture the standard error stream and check what the command
said can be broken with the trace output mixed in. When running
our tests under "bash", however, we can redirect the trace output
to another file descriptor to keep the standard error of programs
being tested intact.
* jk/test-send-sh-x-trace-elsewhere:
test-lib: set BASH_XTRACEFD automatically
Passing "-x" to a test script enables the shell's "set -x"
tracing, which can help with tracking down the command that
is causing a failure. Unfortunately, it can also _cause_
failures in some tests that redirect the stderr of a shell
function. Inside the function the shell continues to
respect "set -x", and the trace output is collected along
with whatever stderr is generated normally by the function.
You can see an example of this by running:
./t0040-parse-options.sh -x -i
which will fail immediately in the first test, as it
expects:
test_must_fail some-cmd 2>output.err
to leave output.err empty (but with "-x" it has our trace
output).
Unfortunately there isn't a portable or scalable solution to
this. We could teach test_must_fail to disable "set -x", but
that doesn't help any of the other functions or subshells.
However, we can work around it by pointing the "set -x"
output to our descriptor 4, which always points to the
original stderr of the test script. Unfortunately this only
works for bash, but it's better than nothing (and other
shells will just ignore the BASH_XTRACEFD variable).
The patch itself is a simple one-liner, but note the caveats
in the accompanying comments.
Automatic tests for our "-x" option may be a bit too meta
(and a pain, because they are bash-specific), but I did
confirm that it works correctly both with regular "-x" and
with "--verbose-only=1". This works because the latter flips
"set -x" off and on for particular tests (if it didn't, we
would get tracing for all tests, as going to descriptor 4
effectively circumvents the verbose flag).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When prefixing a Git call in the test suite with 'debug ', it will
now be run with GDB, allowing the developer to debug test failures
more conveniently.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's easy to miss an "&&"-chain in a test script, like:
test_expect_success 'check something important' '
cmd1 &&
cmd2
cmd3
'
The test harness will notice if cmd3 fails, but a failure of
cmd1 or cmd2 will go unnoticed, as their exit status is lost
after cmd3 runs.
The toy example above is easy to spot because the "cmds" are
all the same length, but real code is much more complicated.
It's also difficult to detect these situations by statically
analyzing the shell code with regexps (like the
check-non-portable-shell script does); there's too much
context required to know whether a &&-chain is appropriate
on a given line or not.
This patch instead lets the shell check each test by
sticking a command with a specific and unusual return code
at the top of each test, like:
(exit 117) &&
cmd1 &&
cmd2
cmd3
In a well-formed test, the non-zero exit from the first
command prevents any of the rest from being run, and the
test's exit code is 117. In a bad test (like the one above),
the 117 is lost, and cmd3 is run.
When we encounter a failure of this check, we abort the test
script entirely. For one thing, we have no clue which subset
of the commands in the test snippet were actually run.
Running further tests would be pointless, because we're now
in an unknown state. And two, this is not a "test failure"
in the traditional sense. The test script is buggy, not the
code it is testing. We should be able to fix these problems
in the script once, and not have them come back later as a
regression in git's code.
After checking a test snippet for --chain-lint, we do still
run the test itself. We could actually have a pure-lint
mode which just checks each test, but there are a few
reasons not to. One, because the tests are executing
arbitrary code, which could impact the later environment
(e.g., that could impact which set of tests we run at all).
And two, because a pure-lint mode would still be expensive
to run, because a significant amount of code runs outside of
the test_expect_* blocks. Instead, this option is designed
to be used as part of a normal test suite run, where it adds
very little overhead.
Turning on this option detects quite a few problems in
existing tests, which will be fixed in subsequent patches.
However, there are a number of places it cannot reach:
- it cannot find a failure to break out of loops on error,
like:
cmd1 &&
for i in a b c; do
cmd2 $i
done &&
cmd3
which will not notice failures of "cmd2 a" or "cmd b"
- it cannot find a missing &&-chain inside a block or
subfunction, like:
foo () {
cmd1
cmd2
}
foo &&
bar
which will not notice a failure of cmd1.
- it only checks tests that you run; every platform will
have some tests skipped due to missing prequisites,
so it's impossible to say from one run that the test
suite is free of broken &&-chains. However, all tests get
run by _somebody_, so eventually we will notice problems.
- it does not operate on test_when_finished or prerequisite
blocks. It could, but these tends to be much shorter and
less of a problem, so I punted on them in this patch.
This patch was inspired by an earlier patch by Jonathan
Nieder:
http://article.gmane.org/gmane.comp.version-control.git/235913
This implementation and all bugs are mine.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We require use of test_must_fail to check expected non-zero exit by
Git itself, but discourage test_must_fail to be used for checking
exit status of non Git commands that are supplied by the system.
The current text explains the reason for the former but not the
latter.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Usually running a test under "-v" makes it clear which
command is failing. However, sometimes it can be useful to
also see a complete trace of the shell commands being run in
the test. You can do so without any support from the test
suite by running "sh -x tXXXX-foo.sh". However, this
produces quite a large bit of output, as we see a trace of
the entire test suite.
This patch instead introduces a "-x" option to the test
scripts (i.e., "./tXXXX-foo.sh -x"). When enabled, this
turns on "set -x" only for the tests themselves. This can
still be a bit verbose, but should keep things to a more
manageable level. You can even use "--verbose-only" to see
the trace only for a specific test.
The implementation is a little invasive. We turn on the "set
-x" inside the "eval" of the test code. This lets the eval
itself avoid being reported in the trace (which would be
long, and redundant with the verbose listing we already
showed). And then after the eval runs, we do some trickery
with stderr to avoid showing the "set +x" to the user.
We also show traces for test_cleanup functions (since they
can impact the test outcome, too). However, we do avoid
running the noop ":" cleanup (the default if the test does
not use test_cleanup at all), as it creates unnecessary
noise in the "set -x" output.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allow specifying only certain individual test pieces to be run
using a range notation (e.g. "t1234-test.sh --run='1-4 6 8 9-'").
* ib/test-selectively-run:
t0000-*.sh: fix the GIT_SKIP_TESTS sub-tests
test-lib: '--run' to run only specific tests
test-lib: tests skipped by GIT_SKIP_TESTS say so
test-lib: document short options in t/README
test_write_lines carefully quotes its arguments as "$@", so
test_write_lines "a b" c
writes two lines as requested, not three.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allow better control of the set of tests that will be executed for a
single test suite. Mostly useful while debugging or developing as it
allows to focus on a specific test.
Signed-off-by: Ilya Bobyr <ilya.bobyr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
