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+// 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 interface{} // To be sent on signal channel when done.
+ signal chan interface{} // 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 ...interface{}) { 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 ...interface{}) { c.log(fmt.Sprintf(format, args...)) }
+
+// Error is equivalent to Log() followed by Fail().
+func (c *common) Error(args ...interface{}) {
+ c.log(fmt.Sprintln(args...))
+ c.Fail()
+}
+
+// Errorf is equivalent to Logf() followed by Fail().
+func (c *common) Errorf(format string, args ...interface{}) {
+ c.log(fmt.Sprintf(format, args...))
+ c.Fail()
+}
+
+// Fatal is equivalent to Log() followed by FailNow().
+func (c *common) Fatal(args ...interface{}) {
+ c.log(fmt.Sprintln(args...))
+ c.FailNow()
+}
+
+// Fatalf is equivalent to Logf() followed by FailNow().
+func (c *common) Fatalf(format string, args ...interface{}) {
+ 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 interface{})
+
+ 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 interface{}),
+ },
+ 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)
+ }
+ }
+}