The package doc for the testing package doesn't have a simple
example demonstrating how to write a test with an expectation. The doc
has simple examples for benchmarks, examples, and skipping, and it would be
useful for people new to writing tests in Go.
Also moved the skip example further down because it references tests and
benchmarks but benchmarks haven't been discussed in detail until the
next section. Skip is also a less used feature and it seems misplaced to
sit so high up in the package documentation. As an example, Skip is used
570 times the Go code repository which is significantly less than Error
and Fatal that are used 23,303 times.
Also changed 'sample' to 'simple' in other places in the package documentation
to keep the language used consistent when describing the small examples.
Fixes#27839
Change-Id: Ie01a3751986ee61adf2a2f2eda59cc182342baa7
GitHub-Last-Rev: 7357bfdcd2
GitHub-Pull-Request: golang/go#27840
Reviewed-on: https://go-review.googlesource.com/c/137175
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
When running benchmarks with profilers and trying to
compare one run against another, it is very useful to be
able to force each run to execute exactly the same number
of iterations.
Discussion on the proposal issue #24735 led to the decision
to overload -benchtime, so that instead of saying
-benchtime 10s to run a benchmark for 10 seconds,
you say -benchtime 100x to run a benchmark 100 times.
Fixes#24735.
Change-Id: Id17c5bd18bd09987bb48ed12420d61ae9e200fd7
Reviewed-on: https://go-review.googlesource.com/c/139258
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
If the test has already completed when a go routine with a panic
handler reports an error the location of the error call is lost.
Added logDepth to be able to log location of failure at different
depths down the stack.
Fixes#26720
Change-Id: I8b7789ddae757ef6f4bd315cb20356709f4fadec
Reviewed-on: https://go-review.googlesource.com/c/127596
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
I omitted vendor directories and anything necessary for bootstrapping.
(Tested by bootstrapping with Go 1.4)
Updates #27864
Change-Id: I7d9b68d0372d3a34dee22966cca323513ece7e8a
Reviewed-on: https://go-review.googlesource.com/137856
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The previous CL (https://go-review.googlesource.com/c/go/+/96756)
added comments that didn't really say much, but there is something
so say: what the units are and that they are indexed starting at 1.
Add a more helpful comment on the type, and also follow proper
style by using initial capitals and a period.
Change-Id: Id19cd5f392faf7c7bac034073f276cc770589075
Reviewed-on: https://go-review.googlesource.com/121875
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Fill in the missing descriptions for the CoverBlock struct fields
Change-Id: I9257881a19b01e5cfe61cf19a91375b6d7cc68ef
GitHub-Last-Rev: f5b9e1d49d
GitHub-Pull-Request: golang/go#24079
Reviewed-on: https://go-review.googlesource.com/96756
Reviewed-by: Andrew Bonventre <andybons@golang.org>
Run-TryBot: Andrew Bonventre <andybons@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This reverts golang.org/cl/110775
Reason for revert: this is causing huge slow-dows on every run after
the 1st, on various benchmarks, on multiple architectures (see Issue
25622 for details). It's just a nice-to-have little optimization, and
we're near the 1st go1.11 beta release, so I'm reverting it.
Fixes#25622
Change-Id: I758ade4af4abf764abd8336d404396992d11a0c6
Reviewed-on: https://go-review.googlesource.com/115535
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Since subtests and subbenchmarks run in a separate goroutine, and thus
a separate stack, this entails capturing the stack trace at the point
tb.Run is called. The work of getting the file and line information from
this stack is only done when needed, however.
Continuing the search into the parent test also requires temporarily
holding its mutex. Since Run does not hold it while waiting for the
subtest to complete, there should be no risk of a deadlock due to this.
Fixes#24128
Change-Id: If0bb169f3ac96bd48794624e619ade7edb599f83
Reviewed-on: https://go-review.googlesource.com/108658
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
When running a benchmark multiple times, instead of re-computing the
value of b.N each time, use the value found by the first run.
For
go test -bench=. -benchtime 3s -count 2 p_test.go
on the benchmark in the linked issue; before:
BenchmarkBenchmark-4 500 10180593 ns/op
--- BENCH: BenchmarkBenchmark-4
p_test.go:13: single call took 10.111079ms
p_test.go:13: single call took 1.017298685s
p_test.go:13: single call took 5.090096124s
BenchmarkBenchmark-4 500 10182164 ns/op
--- BENCH: BenchmarkBenchmark-4
p_test.go:13: single call took 10.098169ms
p_test.go:13: single call took 1.017712905s
p_test.go:13: single call took 5.090898517s
PASS
ok command-line-arguments 12.244s
and after:
BenchmarkBenchmark-4 500 10177076 ns/op
--- BENCH: BenchmarkBenchmark-4
p_test.go:13: single call took 10.091301ms
p_test.go:13: single call took 1.016943125s
p_test.go:13: single call took 5.088376028s
BenchmarkBenchmark-4 500 10171497 ns/op
--- BENCH: BenchmarkBenchmark-4
p_test.go:13: single call took 10.140245ms
p_test.go:13: single call took 5.085605921s
PASS
ok command-line-arguments 11.218s
Fixes#23423
Change-Id: Ie66a8c5ac43881eb8741e14105db28745b4d56d3
Reviewed-on: https://go-review.googlesource.com/110775
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
We need to grab the mutex before we can access it.
Fixes#24438
Change-Id: Idd6130036691acec5bc5f8b40d6884f8db1d9d3c
Reviewed-on: https://go-review.googlesource.com/101283
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The Go's heap profile contains four kinds of samples
(inuse_space, inuse_objects, alloc_space, and alloc_objects).
The pprof tool by default chooses the inuse_space (the bytes
of live, in-use objects). When analyzing the current memory
usage the choice of inuse_space as the default may be useful,
but in some cases, users are more interested in analyzing the
total allocation statistics throughout the program execution.
For example, when we analyze the memory profile from benchmark
or program test run, we are more likely interested in the whole
allocation history than the live heap snapshot at the end of
the test or benchmark.
The pprof tool provides flags to control which sample type
to be used for analysis. However, it is one of the less-known
features of pprof and we believe it's better to choose the
right type of samples as the default when producing the profile.
This CL introduces a new type of profile, "allocs", which is
the same as the "heap" profile but marks the alloc_space
as the default type unlike heap profiles that use inuse_space
as the default type.
'go test -memprofile=...' command is changed to use the new
"allocs" profile type instead of the traditional "heap" profile.
Fixes#24443
Change-Id: I012dd4b6dcacd45644d7345509936b8380b6fbd9
Reviewed-on: https://go-review.googlesource.com/102696
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>
When a test calls t.Fatal()/t.Fatalf(), only deferred code will execute.
Increment the failure count as part of a deferred call.
Fixes#24412
Change-Id: Ibb154015fcd3d0fb7739718fdda8c9ad22f9e896
Reviewed-on: https://go-review.googlesource.com/101035
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Fixed a broken link to a section in the documentation for the
test flags for the go command.
Change-Id: Ic4bdd4965aac7856dd13a2adda9d774b9bae4113
GitHub-Last-Rev: 15bda34067
GitHub-Pull-Request: golang/go#24613
Reviewed-on: https://go-review.googlesource.com/103835
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
-race sets a hard cap of 8,192, which is easily hit while testing.
Fixes#23611
Change-Id: I0f720ec39c82c2194a485d437d6373f4bdc8a9c1
Reviewed-on: https://go-review.googlesource.com/103160
Reviewed-by: Rob Pike <r@golang.org>
I grepped for "bytes.Buffer" and "buf.String" and mostly ignored test
files. I skipped a few on purpose and probably missed a few others,
but otherwise I think this should be most of them.
Updates #18990
Change-Id: I5a6ae4296b87b416d8da02d7bfaf981d8cc14774
Reviewed-on: https://go-review.googlesource.com/102479
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Don’t panic if a subtest inadvertently calls FailNow
on a parent’s T. Instead, report the offending subtest
while still reporting the error with the ancestor test and
keep exiting goroutines.
Note that this implementation has a race if parallel
subtests are failing the parent concurrently.
This is fine:
Calling FailNow on a parent is considered an error
in principle, at the moment, and is reported if it is
detected. Having the race allows the race detector
to detect the error as well.
Fixes#22882
Change-Id: Ifa6d5e55bb88f6bcbb562fc8c99f1f77e320015a
Reviewed-on: https://go-review.googlesource.com/97635
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
Reviewed-by: Kunpei Sakai <namusyaka@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
In func TestXxxx(*testing.T) the Xxxx can be anything that can appear
in an identifier, but can't start with a lowercase letter. Clarify the docs.
Fixes#23322
Change-Id: I5c297916981f7e3890ee955d12bc7422a75488e2
Reviewed-on: https://go-review.googlesource.com/86001
Reviewed-by: Rob Pike <r@golang.org>
Tests exist that call m.Run in a loop‽
Now we have one too.
Fixes#23129.
Change-Id: I8cbecb724f239ae14ad45d75e67d12c80e41c994
Reviewed-on: https://go-review.googlesource.com/83956
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
t.Run(f) does not wait for f after f calls t.Parallel.
Otherwise it would be impossible to create new
parallel sibling subtests for f.
Fixes#22993.
Change-Id: I27e1555ab1ff608eb8155db261d5e7ee8f486aef
Reviewed-on: https://go-review.googlesource.com/83880
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
When we write a cached test result, we now also write a log of the
environment variables and files inspected by the test run,
along with a hash of their content. Before reusing a cached test result,
we recompute the hash of the content specified by the log, and only
use the result if that content has not changed.
This makes test caching behave correctly for tests that consult
environment variables or stat or read files or directories.
Fixes#22593.
Change-Id: I8608798e73c90e0c1911a38bf7e03e1232d784dc
Reviewed-on: https://go-review.googlesource.com/81895
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The test binaries accept -timeout=0 to mean no timeout,
but then the backup timer in cmd/go kills the test after 1 minute.
Make cmd/go understand this special case and change
behavior accordingly.
Fixes#14780.
Change-Id: I66bf517173a4ad21d53a5ee88d163f04b8929fb6
Reviewed-on: https://go-review.googlesource.com/81499
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
It's not safe (it crashes), and it's also useless: if you run
multiple benchmarks in parallel you will not get reliable
timing results from any of them.
Fixes#18603.
Change-Id: I00e5a72f7c98151543cf7d5573c38383276e391a
Reviewed-on: https://go-review.googlesource.com/80841
Reviewed-by: Ian Lance Taylor <iant@golang.org>
When -test.failfast flag is provided to go test,
no new tests get started after the first failure.
Fixes#21700
Change-Id: I0092e72f25847af05e7c8e1b811dcbb65a00cbe7
Reviewed-on: https://go-review.googlesource.com/74450
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
This should make parallel execution a bit clearer.
With -p=1 it should make the execution completely unambiguous.
Fixes#19280.
Change-Id: Ib48cdfe96896d01b0d8f98ccb2fab614407a7d92
Reviewed-on: https://go-review.googlesource.com/49430
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
strings.LastIndexByte was introduced in go1.5 and it can be used
effectively wherever the second argument to strings.LastIndex is
exactly one byte long.
This avoids generating unnecessary string symbols and saves
a few calls to strings.LastIndex.
Change-Id: I7b5679d616197b055cffe6882a8675d24a98b574
Reviewed-on: https://go-review.googlesource.com/66372
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Most of these are return values that were part of a receiving parameter,
so they're still accessible.
A few others are not, but those have never had a use.
Found with github.com/mvdan/unparam, after Kevin Burke's suggestion that
the tool should also warn about unused result parameters.
Change-Id: Id8b5ed89912a99db22027703a88bd94d0b292b8b
Reviewed-on: https://go-review.googlesource.com/55910
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Otherwise, if there are any parallel tests, it will hang and panic with
"all goroutines are asleep - deadlock!".
Do not use flag.Uint to handle the error for us because we also want to
error on N==0, and because it would make setting the default to
GOMAXPROCS(0) more difficult, since it's an int.
Check for it right after flag.Parse, and mimic flag errors by printing
the usage and returning exit code 2.
Fixes#20542.
Change-Id: I0c9d4587f83d406a8f5e42ed74e40be46d639ffb
Reviewed-on: https://go-review.googlesource.com/54150
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This addresses the case of a -timeout panic, but not the more
general case of a signal arriving. See CL 48370 and CL 44352
for recent difficulties in that area.
"-timeout" here means flag usage to distinguish from the
default timeout termination which uses signals.
Fixes#19394
Change-Id: I5452d5422c0c080e940cbcc8c6606049975268c6
Reviewed-on: https://go-review.googlesource.com/48491
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Currently all package tests are executed once
with Parallel tests executed in parallel.
Then this process is repeated count*cpu times.
Tests are not parallelized over count*cpu.
Parallelizing over cpu is not possible as
GOMAXPROCS is a global setting. But it is
possible for count.
Parallelize over count.
Brings down testing of my package with -count=100
form 10s to 0.3s.
Change-Id: I76d8322adeb8c5c6e70b99af690291fd69d6402a
Reviewed-on: https://go-review.googlesource.com/44830
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The code was adding race.Errors to t.raceErrors before checking
Failed, but Failed was using t.raceErrors+race.Errors. We don't want
to change Failed, since that would affect tests themselves, so modify
the harness to not unnecessarily change t.raceErrors.
Updates #19851Fixes#21338
Change-Id: I7bfdf281f90e045146c92444f1370d55c45221d4
Reviewed-on: https://go-review.googlesource.com/54050
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
SkipNow and FailNow must be called from the goroutine running the
test. This is already documented, but it's easy to call them by
mistake when writing subtests. In the following:
func TestPanic(t *testing.T) {
t.Run("", func(t2 *testing.T) {
t.FailNow() // BAD: should be t2.FailNow()
})
}
the FailNow call on the outer t *testing.T correctly triggers a panic
panic: test executed panic(nil) or runtime.Goexit
The error message confuses users (see issues #17421, #21175) because
there is no way to trace back the relevant part of the message ("test
executed ... runtime.Goexit") to a bad FailNow call without checking
the testing package source code and finding out that FailNow calls
runtime.Goexit.
To help users debug the panic message, mention in the SkipNow and
FailNow documentation that they stop execution by calling
runtime.Goexit.
Fixes#21175
Change-Id: I0a3e5f768e72b464474380cfffbf2b67396ac1b5
Reviewed-on: https://go-review.googlesource.com/52770
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Fixes#21205
Change-Id: I81b001eb42cbf2a5d5b7b82eb63548b22f501be5
Reviewed-on: https://go-review.googlesource.com/52110
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
CL 44352 changed the behavior of SIGINT, which can break tests that
themselves use SIGINT. I think we can only implement this if the
testing package has a way to know whether the code under test is using
SIGINT, but os/signal does not provide an API for that. Roll back for
1.9 and think about this again for 1.10.
Updates #19397
Change-Id: I021c314db2b9d0a80d0088b120a6ade685459990
Reviewed-on: https://go-review.googlesource.com/48370
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Now that ReadMemStats is fast (CL 34937), CL 36791 is not so
necessary, and causes confusion. See #20863
This was already partially reverted in CL 46612 but missed two of the
spots.
Fixes#20863
Change-Id: I1307a0f7b1f9e86e8b6ceaa6a677f24f13431110
Reviewed-on: https://go-review.googlesource.com/47350
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Apparently, "all such calls must happen" means that the t.Run call
must *return* before the outer test function returns, or the calls
will cause a data race on t.ran.
Clarify the docs.
Fixes#20339
Change-Id: I191a9af2a9095be1e0aaf10b79c30e00a9c495cb
Reviewed-on: https://go-review.googlesource.com/47150
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
If the only way the user indicates they want alloc stats shown
is via ReportAllocs, we don't know that until benchFunc is run.
Therefore, StopTimer's ReadMemStats will return incorrect data
for single cycle runs since there's no counterpart ReadMemStats from
StartTimer that initializes alloc stats.
It appears that this bug was introduced by CL 46612,
"testing: only call ReadMemStats if necessary when benchmarking"
Fixes#20590
Change-Id: I3b5ef91677823f4b98011880a3be15423baf7e33
Reviewed-on: https://go-review.googlesource.com/46612
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Also reword the testing/quick.Config field docs to conform to the
normal subject-first style. Without that style, godoc links
/pkg/testing/quick/#Config.Rand to the wrong line, since it doesn't
recognize the preceding comment as necessarily being attached.
Fixes#20809
Change-Id: I9aebbf763eed9b1ab1a153fa11850d88a65571c6
Reviewed-on: https://go-review.googlesource.com/46910
Reviewed-by: Ian Lance Taylor <iant@golang.org>
If you have BenchmarkX1 with sub-benchmark Y
and you have BenchmarkX2 with no sub-benchmarks,
then
go test -bench=X/Y
runs BenchmarkX1 once with b.N=1 (to find out about Y)
and then not again, because it has sub-benchmarks,
but arguably also because we're interested in Y.
In contrast, it runs BenchmarkX2 in full, even though clearly
that is not relevant to the match X/Y. We do have to run X2
once with b.N=1 to probe for having X2/Y, but we should not
run it with larger b.N.
Fixes#20589.
Change-Id: Ib86907e844f34dcaac6cd05757f57db1019201d0
Reviewed-on: https://go-review.googlesource.com/46031
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
Because of parallel tests, which have stalled executions, the RUN
output of a test can be much earlier than its completion output resulting
in hard-to-read verbose output.
The tests are displayed in the order in which the output shows
that they began, to make it easy to line up with the "RUN" output.
Similarly, the definitions of when tests begin and complete is
determined by when RUN and FAIL/SKIP/PASS are output since the
focus of this code is on enhancing readability.
Fixes#19397
Change-Id: I4d0ca3fd268b620484e7a190117f79a33b3dc461
Reviewed-on: https://go-review.googlesource.com/44352
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
