golang testing 代码
文件路径：/src/go/doc/testdata/testing.go
/ Copyright 2009 The Go Authors. All rights reserved.
/ Use of this source code is governed by a BSD-style
/ license that can be found in the LICENSE file.
/ Package testing provides support for automated testing of Go packages.
/ It is intended to be used in concert with the “go test” utility, which automates
/ execution of any function of the form
/ func TestXxx(*testing.T)
/ where Xxx can be any alphanumeric string (but the first letter must not be in
/ [a-z]) and serves to identify the test routine.
/ These TestXxx routines should be declared within the package they are testing.
/
/ Functions of the form
/ func BenchmarkXxx(*testing.B)
/ are considered benchmarks, and are executed by go test when the -test.bench
/ flag is provided.
/
/ A sample benchmark function looks like this:
/ func BenchmarkHello(b *testing.B) {
/ for i := 0; i < b.N; i++ {
/ fmt.Sprintf("hello")
/ }
/ }
/ The benchmark package will vary b.N until the benchmark function lasts
/ long enough to be timed reliably. The output
/ testing.BenchmarkHello 10000000 282 ns/op
/ means that the loop ran 10000000 times at a speed of 282 ns per loop.
/
/ If a benchmark needs some expensive setup before running, the timer
/ may be stopped:
/ func BenchmarkBigLen(b *testing.B) {
/ b.StopTimer()
/ big := NewBig()
/ b.StartTimer()
/ for i := 0; i < b.N; i++ {
/ big.Len()
/ }
/ }
package testing
import (
"flag"
"fmt"
"os"
"runtime"
"runtime/pprof"
"strconv"
"strings"
"time"
)
var (
/ The short flag requests that tests run more quickly, but its functionality
/ is provided by test writers themselves. The testing package is just its
/ home. The all.bash installation script sets it to make installation more
/ efficient, but by default the flag is off so a plain "go test" will do a
/ full test of the package.
short = flag.Bool("test.short", false, "run smaller test suite to save time")
/ Report as tests are run; default is silent for success.
chatty = flag.Bool("test.v", false, "verbose: print additional output")
match = flag.String("test.run", "", "regular expression to select tests to run")
memProfile = flag.String("test.memprofile", "", "write a memory profile to the named file after execution")
memProfileRate = flag.Int("test.memprofilerate", 0, "if >=0, sets runtime.MemProfileRate")
cpuProfile = flag.String("test.cpuprofile", "", "write a cpu profile to the named file during execution")
timeout = flag.Duration("test.timeout", 0, "if positive, sets an aggregate time limit for all tests")
cpuListStr = flag.String("test.cpu", "", "comma-separated list of number of CPUs to use for each test")
parallel = flag.Int("test.parallel", runtime.GOMAXPROCS(0), "maximum test parallelism")
cpuList []int
)
/ common holds the elements common between T and B and
/ captures common methods such as Errorf.
type common struct {
output []byte / Output generated by test or benchmark.
failed bool / Test or benchmark has failed.
start time.Time / Time test or benchmark started
duration time.Duration
self any / To be sent on signal channel when done.
signal chan any / Output for serial tests.
}
/ Short reports whether the -test.short flag is set.
func Short() bool {
return *short
}
/ decorate inserts the final newline if needed and indentation tabs for formatting.
/ If addFileLine is true, it also prefixes the string with the file and line of the call site.
func decorate(s string, addFileLine bool) string {
if addFileLine {
_, file, line, ok := runtime.Caller(3) / decorate + log + public function.
if ok {
/ Truncate file name at last file name separator.
if index := strings.LastIndex(file, "/"); index >= 0 {
file = file[index+1:]
} else if index = strings.LastIndex(file, "\\"); index >= 0 {
file = file[index+1:]
}
} else {
file = "???"
line = 1
}
s = fmt.Sprintf("%s:%d: %s", file, line, s)
}
s = "\t" + s / Every line is indented at least one tab.
n := len(s)
if n > 0 && s[n-1] != '\n' {
s += "\n"
n++
}
for i := 0; i < n-1; i++ { / -1 to avoid final newline
if s[i] == '\n' {
/ Second and subsequent lines are indented an extra tab.
return s[0:i+1] + "\t" + decorate(s[i+1:n], false)
}
}
return s
}
/ T is a type passed to Test functions to manage test state and support formatted test logs.
/ Logs are accumulated during execution and dumped to standard error when done.
type T struct {
common
name string / Name of test.
startParallel chan bool / Parallel tests will wait on this.
}
/ Fail marks the function as having failed but continues execution.
func (c *common) Fail() { c.failed = true }
/ Failed reports whether the function has failed.
func (c *common) Failed() bool { return c.failed }
/ FailNow marks the function as having failed and stops its execution.
/ Execution will continue at the next Test.
func (c *common) FailNow() {
c.Fail()
/ Calling runtime.Goexit will exit the goroutine, which
/ will run the deferred functions in this goroutine,
/ which will eventually run the deferred lines in tRunner,
/ which will signal to the test loop that this test is done.
/
/ A previous version of this code said:
/
/ c.duration = ...
/ c.signal <- c.self
/ runtime.Goexit()
/
/ This previous version duplicated code (those lines are in
/ tRunner no matter what), but worse the goroutine teardown
/ implicit in runtime.Goexit was not guaranteed to complete
/ before the test exited. If a test deferred an important cleanup
/ function (like removing temporary files), there was no guarantee
/ it would run on a test failure. Because we send on c.signal during
/ a top-of-stack deferred function now, we know that the send
/ only happens after any other stacked defers have completed.
runtime.Goexit()
}
/ log generates the output. It's always at the same stack depth.
func (c *common) log(s string) {
c.output = append(c.output, decorate(s, true)...)
}
/ Log formats its arguments using default formatting, analogous to Println(),
/ and records the text in the error log.
func (c *common) Log(args ...any) { c.log(fmt.Sprintln(args...)) }
/ Logf formats its arguments according to the format, analogous to Printf(),
/ and records the text in the error log.
func (c *common) Logf(format string, args ...any) { c.log(fmt.Sprintf(format, args...)) }
/ Error is equivalent to Log() followed by Fail().
func (c *common) Error(args ...any) {
c.log(fmt.Sprintln(args...))
c.Fail()
}
/ Errorf is equivalent to Logf() followed by Fail().
func (c *common) Errorf(format string, args ...any) {
c.log(fmt.Sprintf(format, args...))
c.Fail()
}
/ Fatal is equivalent to Log() followed by FailNow().
func (c *common) Fatal(args ...any) {
c.log(fmt.Sprintln(args...))
c.FailNow()
}
/ Fatalf is equivalent to Logf() followed by FailNow().
func (c *common) Fatalf(format string, args ...any) {
c.log(fmt.Sprintf(format, args...))
c.FailNow()
}
/ Parallel signals that this test is to be run in parallel with (and only with)
/ other parallel tests in this CPU group.
func (t *T) Parallel() {
t.signal <- (*T)(nil) / Release main testing loop
<-t.startParallel / Wait for serial tests to finish
}
/ An internal type but exported because it is cross-package; part of the implementation
/ of go test.
type InternalTest struct {
Name string
F func(*T)
}
func tRunner(t *T, test *InternalTest) {
t.start = time.Now()
/ When this goroutine is done, either because test.F(t)
/ returned normally or because a test failure triggered
/ a call to runtime.Goexit, record the duration and send
/ a signal saying that the test is done.
defer func() {
t.duration = time.Now().Sub(t.start)
t.signal <- t
}()
test.F(t)
}
/ An internal function but exported because it is cross-package; part of the implementation
/ of go test.
func Main(matchString func(pat, str string) (bool, error), tests []InternalTest, benchmarks []InternalBenchmark, examples []InternalExample) {
flag.Parse()
parseCpuList()
before()
startAlarm()
testOk := RunTests(matchString, tests)
exampleOk := RunExamples(examples)
if !testOk || !exampleOk {
fmt.Println("FAIL")
os.Exit(1)
}
fmt.Println("PASS")
stopAlarm()
RunBenchmarks(matchString, benchmarks)
after()
}
func (t *T) report() {
tstr := fmt.Sprintf("(%.2f seconds)", t.duration.Seconds())
format := "--- %s: %s %s\n%s"
if t.failed {
fmt.Printf(format, "FAIL", t.name, tstr, t.output)
} else if *chatty {
fmt.Printf(format, "PASS", t.name, tstr, t.output)
}
}
func RunTests(matchString func(pat, str string) (bool, error), tests []InternalTest) (ok bool) {
ok = true
if len(tests) == 0 {
fmt.Fprintln(os.Stderr, "testing: warning: no tests to run")
return
}
for _, procs := range cpuList {
runtime.GOMAXPROCS(procs)
/ We build a new channel tree for each run of the loop.
/ collector merges in one channel all the upstream signals from parallel tests.
/ If all tests pump to the same channel, a bug can occur where a test
/ kicks off a goroutine that Fails, yet the test still delivers a completion signal,
/ which skews the counting.
var collector = make(chan any)
numParallel := 0
startParallel := make(chan bool)
for i := 0; i < len(tests); i++ {
matched, err := matchString(*match, tests[i].Name)
if err != nil {
fmt.Fprintf(os.Stderr, "testing: invalid regexp for -test.run: %s\n", err)
os.Exit(1)
}
if !matched {
continue
}
testName := tests[i].Name
if procs != 1 {
testName = fmt.Sprintf("%s-%d", tests[i].Name, procs)
}
t := &T{
common: common{
signal: make(chan any),
},
name: testName,
startParallel: startParallel,
}
t.self = t
if *chatty {
fmt.Printf("=== RUN %s\n", t.name)
}
go tRunner(t, &tests[i])
out := (<-t.signal).(*T)
if out == nil { / Parallel run.
go func() {
collector <- <-t.signal
}()
numParallel++
continue
}
t.report()
ok = ok && !out.failed
}
running := 0
for numParallel+running > 0 {
if running < *parallel && numParallel > 0 {
startParallel <- true
running++
numParallel--
continue
}
t := (<-collector).(*T)
t.report()
ok = ok && !t.failed
running--
}
}
return
}
/ before runs before all testing.
func before() {
if *memProfileRate > 0 {
runtime.MemProfileRate = *memProfileRate
}
if *cpuProfile != "" {
f, err := os.Create(*cpuProfile)
if err != nil {
fmt.Fprintf(os.Stderr, "testing: %s", err)
return
}
if err := pprof.StartCPUProfile(f); err != nil {
fmt.Fprintf(os.Stderr, "testing: can't start cpu profile: %s", err)
f.Close()
return
}
/ Could save f so after can call f.Close; not worth the effort.
}
}
/ after runs after all testing.
func after() {
if *cpuProfile != "" {
pprof.StopCPUProfile() / flushes profile to disk
}
if *memProfile != "" {
f, err := os.Create(*memProfile)
if err != nil {
fmt.Fprintf(os.Stderr, "testing: %s", err)
return
}
if err = pprof.WriteHeapProfile(f); err != nil {
fmt.Fprintf(os.Stderr, "testing: can't write %s: %s", *memProfile, err)
}
f.Close()
}
}
var timer *time.Timer
/ startAlarm starts an alarm if requested.
func startAlarm() {
if *timeout > 0 {
timer = time.AfterFunc(*timeout, alarm)
}
}
/ stopAlarm turns off the alarm.
func stopAlarm() {
if *timeout > 0 {
timer.Stop()
}
}
/ alarm is called if the timeout expires.
func alarm() {
panic("test timed out")
}
func parseCpuList() {
if len(*cpuListStr) == 0 {
cpuList = append(cpuList, runtime.GOMAXPROCS(-1))
} else {
for _, val := range strings.Split(*cpuListStr, ",") {
cpu, err := strconv.Atoi(val)
if err != nil || cpu <= 0 {
fmt.Fprintf(os.Stderr, "testing: invalid value %q for -test.cpu", val)
os.Exit(1)
}
cpuList = append(cpuList, cpu)
}
}
}