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Diffstat (limited to 'src/go/doc/testdata/testing.go')
-rw-r--r-- | src/go/doc/testdata/testing.go | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/src/go/doc/testdata/testing.go b/src/go/doc/testdata/testing.go new file mode 100644 index 0000000..52810f7 --- /dev/null +++ b/src/go/doc/testdata/testing.go @@ -0,0 +1,404 @@ +// 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) + } + } +} |