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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 ``gotest'' 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 gotest 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 500000 4076 ns/op
// means that the loop ran 500000 times at a speed of 4076 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"
"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 "gotest" 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.Int64("test.timeout", 0, "if > 0, sets time limit for tests in seconds")
)
// Short reports whether the -test.short flag is set.
func Short() bool {
return *short
}
// Insert final newline if needed and tabs after internal newlines.
func tabify(s string) string {
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' {
return s[0:i+1] + "\t" + tabify(s[i+1:n])
}
}
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 {
errors string
failed bool
ch chan *T
}
// Fail marks the Test function as having failed but continues execution.
func (t *T) Fail() { t.failed = true }
// Failed returns whether the Test function has failed.
func (t *T) Failed() bool { return t.failed }
// FailNow marks the Test function as having failed and stops its execution.
// Execution will continue at the next Test.
func (t *T) FailNow() {
t.Fail()
t.ch <- t
runtime.Goexit()
}
// Log formats its arguments using default formatting, analogous to Print(),
// and records the text in the error log.
func (t *T) Log(args ...interface{}) { t.errors += "\t" + tabify(fmt.Sprintln(args...)) }
// Logf formats its arguments according to the format, analogous to Printf(),
// and records the text in the error log.
func (t *T) Logf(format string, args ...interface{}) {
t.errors += "\t" + tabify(fmt.Sprintf(format, args...))
}
// Error is equivalent to Log() followed by Fail().
func (t *T) Error(args ...interface{}) {
t.Log(args...)
t.Fail()
}
// Errorf is equivalent to Logf() followed by Fail().
func (t *T) Errorf(format string, args ...interface{}) {
t.Logf(format, args...)
t.Fail()
}
// Fatal is equivalent to Log() followed by FailNow().
func (t *T) Fatal(args ...interface{}) {
t.Log(args...)
t.FailNow()
}
// Fatalf is equivalent to Logf() followed by FailNow().
func (t *T) Fatalf(format string, args ...interface{}) {
t.Logf(format, args...)
t.FailNow()
}
// An internal type but exported because it is cross-package; part of the implementation
// of gotest.
type InternalTest struct {
Name string
F func(*T)
}
func tRunner(t *T, test *InternalTest) {
test.F(t)
t.ch <- t
}
// An internal function but exported because it is cross-package; part of the implementation
// of gotest.
func Main(matchString func(pat, str string) (bool, os.Error), tests []InternalTest, benchmarks []InternalBenchmark) {
flag.Parse()
before()
startAlarm()
RunTests(matchString, tests)
stopAlarm()
RunBenchmarks(matchString, benchmarks)
after()
}
func RunTests(matchString func(pat, str string) (bool, os.Error), tests []InternalTest) {
ok := true
if len(tests) == 0 {
println("testing: warning: no tests to run")
}
for i := 0; i < len(tests); i++ {
matched, err := matchString(*match, tests[i].Name)
if err != nil {
println("invalid regexp for -test.run:", err.String())
os.Exit(1)
}
if !matched {
continue
}
if *chatty {
println("=== RUN ", tests[i].Name)
}
ns := -time.Nanoseconds()
t := new(T)
t.ch = make(chan *T)
go tRunner(t, &tests[i])
<-t.ch
ns += time.Nanoseconds()
tstr := fmt.Sprintf("(%.2f seconds)", float64(ns)/1e9)
if t.failed {
println("--- FAIL:", tests[i].Name, tstr)
print(t.errors)
ok = false
} else if *chatty {
println("--- PASS:", tests[i].Name, tstr)
print(t.errors)
}
}
if !ok {
println("FAIL")
os.Exit(1)
}
println("PASS")
}
// 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*1e9, 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")
}