runutil/sequence_test.go - release.go.jiri - Git at Google

 // Copyright 2015 The Vanadium 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 runutil_test

 import (
 	"bytes"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"regexp"
 	"strings"
 	"testing"
 	"time"

 	"v.io/jiri/runutil"
 )

 func rmLineNumbers(s string) string {
 	re := regexp.MustCompile("(.*\\.go):\\d+:(.*)")
 	return re.ReplaceAllString(s, "$1:-:$2")
 }

 func sanitizeTimestamps(s string) string {
 	re := regexp.MustCompile(`\[(\d\d:\d\d:\d\d.\d\d)\]`)
 	return re.ReplaceAllString(s, "[hh:mm:ss.xx]")
 }

 func ExampleSequence() {
 	seq := runutil.NewSequence(nil, os.Stdin, ioutil.Discard, ioutil.Discard, false, false, true)
 	err := seq.
 		Capture(os.Stdout, nil).Run("echo", "a").
 		Capture(os.Stdout, nil).Last("echo", "b")
 	err = seq.
 		Run("echo", "c").
 		Run("xxxxxxx").
 		Capture(os.Stdout, nil).Last("echo", "d")
 	// Get rid of the line#s in the error output.
 	fmt.Println(rmLineNumbers(err.Error()))
 	// Output:
 	// a
 	// b
 	// sequence_test.go:-: Run("xxxxxxx"): exec: "xxxxxxx": executable file not found in $PATH
 }

 // TestStdoutStderr exercises the various possible configurations for stdout and
 // stderr (via NewSequence, Opts, or Capture) as well as the verbose flag.
 func TestStdoutStderr(t *testing.T) {
 	cwd, err := os.Getwd()
 	if err != nil {
 		t.Fatal(err)
 	}
 	dir := "Current Directory: " + cwd

 	// Case 1: we only specify stdout/stderr at constructor time.
 	//
 	// Verbose mode: All the command's output and execution logging goes to
 	// stdout, execution error messages to stderr.
 	//
 	// Non-Verbose mode: No stdout output; execution error messages to
 	// stderr.
 	for _, verbose := range []bool{false, true} {
 		var cnstrStdout, cnstrStderr bytes.Buffer
 		seq := runutil.NewSequence(nil, os.Stdin, &cnstrStdout, &cnstrStderr, false, false, verbose)
 		seq.Run("bash", "-c", "echo a; echo b >&2").
 			Timeout(time.Microsecond).
 			Run("sleep", "10000")
 		wantA, wantB := "", ""
 		if verbose {
 			// stdout, stderr output can be interleaved in arbitrary order.
 			pre := `[hh:mm:ss.xx] >> bash -c "echo a; echo b >&2"
 [hh:mm:ss.xx] >> OK`
 			post := `[hh:mm:ss.xx] >> sleep 10000
 [hh:mm:ss.xx] >> TIMED OUT
 `
 			wantA = pre + `
 a
 b
 ` + post
 			wantB = pre + `
 b
 a
 ` + post
 		}
 		if got := sanitizeTimestamps(cnstrStdout.String()); got != wantA && got != wantB {
 			t.Errorf("verbose: %t, got %v, want either %v or %v", verbose, got, wantA, wantB)
 		}
 		if got, want := cnstrStderr.String(), "Waiting for command to exit: [\"sleep\" \"10000\"]\n"+dir+"\n"; want != got {
 			t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
 		}
 	}

 	// Case 2: we specify stdout/stderr at constructor time, and also via
 	// Capture.
 	//
 	// Verbose mode: The command execution log goes to constructor stdout,
 	// command execution errors go to constructor stderr, and the
 	// stdout/stderr output from the command goes to capture stdout/stderr
 	// respectively.
 	//
 	// Non-Verbose mode: The stdout/stderr output from the command goes to
 	// capture stdout/stderr respectively.  No command execution log, but
 	// the command execution errors go to constructor stderr.
 	for _, verbose := range []bool{false, true} {
 		var cnstrStdout, cnstrStderr, captureStdout, captureStderr bytes.Buffer
 		seq := runutil.NewSequence(nil, os.Stdin, &cnstrStdout, &cnstrStderr, false, false, verbose)
 		seq.Capture(&captureStdout, &captureStderr).
 			Run("bash", "-c", "echo a; echo b >&2").
 			Timeout(time.Microsecond).
 			Run("sleep", "10000")
 		want := ""
 		if verbose {
 			want = `[hh:mm:ss.xx] >> bash -c "echo a; echo b >&2"
 [hh:mm:ss.xx] >> OK
 [hh:mm:ss.xx] >> sleep 10000
 [hh:mm:ss.xx] >> TIMED OUT
 `
 		}
 		if got := sanitizeTimestamps(cnstrStdout.String()); want != got {
 			t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
 		}
 		if got, want := cnstrStderr.String(), "Waiting for command to exit: [\"sleep\" \"10000\"]\n"+dir+"\n"; want != got {
 			t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
 		}
 		if got, want := captureStdout.String(), "a\n"; want != got {
 			t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
 		}
 		if got, want := captureStderr.String(), "b\n"; want != got {
 			t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
 		}
 	}

 	// Case 3: we specify stdout/stderr at constructor and use nil
 	// with Capture to verify that the constructor values are used.
 	var cnstrStdout, cnstrStderr, captureStdout, captureStderr bytes.Buffer
 	seq := runutil.NewSequence(nil, os.Stdin, &cnstrStdout, &cnstrStderr, false, false, false)
 	err = seq.
 		Capture(&captureStdout, nil).Run("bash", "-c", "echo a; echo b >&2").
 		Capture(nil, &captureStderr).Last("bash", "-c", "echo c; echo d >&2")

 	if got, want := cnstrStdout.String(), "c\n"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 	if got, want := cnstrStderr.String(), "b\n"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 	if got, want := captureStdout.String(), "a\n"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 	if got, want := captureStderr.String(), "d\n"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 }

 func TestSequence(t *testing.T) {
 	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
 	if got, want := seq.Run("echo", "a").Done(), error(nil); got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 	var out bytes.Buffer
 	err := seq.
 		Capture(&out, nil).Run("echo", "hello").
 		Capture(&out, nil).Run("echo", "world").
 		Done()
 	if err != nil {
 		t.Fatal(err)
 	}
 	if got, want := out.String(), "hello\nworld\n"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 	out.Reset()
 	env := map[string]string{
 		"MYTEST":  "hi",
 		"MYTEST2": "there",
 	}
 	err = seq.
 		Capture(&out, nil).Env(env).Run("sh", "-c", "echo $MYTEST").
 		Env(env).Capture(&out, nil).Run("sh", "-c", "echo $MYTEST2").
 		Done()
 	if err != nil {
 		t.Fatal(err)
 	}
 	if got, want := out.String(), "hi\nthere\n"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 	out.Reset()
 	err = seq.Run("./bound-to-fail", "fail").Done()
 	if err == nil {
 		t.Fatalf("should have experience an error")
 	}
 	if got, want := rmLineNumbers(err.Error()), "sequence_test.go:-: Run(\"./bound-to-fail\", \"fail\"): fork/exec ./bound-to-fail: no such file or directory"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 	err = seq.
 		Capture(&out, nil).Run("echo", "works, despite previous error").Done()
 	if err != nil {
 		t.Fatal(err)
 	}
 	if got, want := out.String(), "works, despite previous error\n"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 	out.Reset()
 	err = seq.Timeout(time.Second).Run("sleep", "10").Done()
 	if got, want := rmLineNumbers(err.Error()), "sequence_test.go:-: Run(\"sleep\", \"10\"): command timed out"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 }

 // Test that modifiers don't get applied beyond the first invocation of Run.
 func TestSequenceModifiers(t *testing.T) {
 	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
 	var out bytes.Buffer
 	env := map[string]string{
 		"MYTEST": "hi",
 	}
 	err := seq.
 		Capture(&out, nil).Env(env).Run("sh", "-c", "echo $MYTEST").
 		Capture(&out, nil).Last("sh", "-c", "echo $MYTEST")
 	if err != nil {
 		t.Fatal(err)
 	}
 	if got, want := out.String(), "hi\n\n"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 	out.Reset()

 	err = seq.
 		Capture(&out, nil).Run("echo", "hello").
 		Run("echo", "world").
 		Done()
 	if err != nil {
 		t.Fatal(err)
 	}
 	if got, want := out.String(), "hello\n"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 	out.Reset()

 	in := bytes.Buffer{}
 	in.WriteString("Hello\n")
 	in.WriteString("World\n")

 	if err := seq.Read(&in).Capture(&out, nil).Last("sh", "-c", "read x; echo $x; read y; echo $y"); err != nil {
 		t.Fatal(err)
 	}
 	if got, want := out.String(), "Hello\nWorld\n"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 }

 func TestSequenceOutputOnError(t *testing.T) {
 	var out bytes.Buffer
 	// Only the output from the command that generates an error is written
 	// to stderr (i.e. out) when not in verbose mode.
 	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, &out, false, false, false)
 	err := seq.Run("sh", "-c", "echo not me").
 		Run("sh", "-c", "echo ooh; echo ah; echo me; exit 1").
 		Last("sh", "-c", "echo not me either")
 	if err == nil {
 		t.Errorf("expected an error")
 	}
 	if got, want := out.String(), "oh\nah\nme\n"; !strings.Contains(got, want) {
 		t.Errorf("got %v doesn't contain %v", got, want)
 	}
 	if got, notWant := out.String(), "not me"; strings.Contains(got, notWant) {
 		t.Errorf("got %v contains %v", got, notWant)
 	}
 	out.Reset()

 	err = seq.Run("sh", "-c", "echo hard to not include me").
 		Run("sh", "-c", "echo ooh; echo ah; echo me").
 		Last("sh", "-c", "echo not me either")
 	if err != nil {
 		t.Error(err)
 	}
 	if got, want := len(out.String()), 0; got != want {
 		t.Logf(out.String())
 		t.Errorf("got %v, want %v", got, want)
 	}
 	out.Reset()

 	err = seq.Last("sh", "-c", "echo should see an error; exit 1")
 	if err == nil {
 		t.Errorf("expected an error")
 	}
 	if got, want := out.String(), "should see an error"; !strings.Contains(got, want) {
 		t.Errorf("got %v, want %v", got, want)
 	}
 }

 type timestamped struct {
 	times []time.Time
 	data  [][]byte
 }

 func (t *timestamped) Write(p []byte) (n int, err error) {
 	t.times = append(t.times, time.Now())
 	t.data = append(t.data, p)
 	return len(p), nil
 }

 func TestSequenceStreaming(t *testing.T) {
 	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
 	ts := &timestamped{}
 	err := seq.
 		Capture(ts, nil).Last("sh", "-c", `
 	for i in $(seq 1 5); do
 		echo $i
 		sleep 1
 	done`)
 	if err != nil {
 		t.Fatal(err)
 	}
 	if got, want := len(ts.data), 5; got != want {
 		t.Fatalf("got %v, want %v", got, want)
 	}
 	prev := ts.times[0]
 	for _, nth := range ts.times[1:] {
 		if nth.Sub(prev) < 500*time.Millisecond {
 			t.Errorf("times %s and %s are too close together", nth, prev)
 		}
 		prev = nth
 	}
 }

 func TestSequenceTerminatingMethod(t *testing.T) {
 	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
 	filename := "./test-file"
 	fi, err := os.Create(filename)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer os.Remove(filename)
 	data, err := seq.Capture(fi, nil).Run("echo", "aha").ReadFile(filename)
 	if err != nil {
 		t.Fatal(err)
 	}
 	if got, want := string(data), "aha\n"; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 }

 func getwd(t *testing.T) string {
 	here, err := os.Getwd()
 	if err != nil {
 		t.Fatal(err)
 	}
 	return here
 }

 func TestSequencePushPop(t *testing.T) {
 	here := getwd(t)
 	s := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
 	components := []string{here, "test", "a", "b", "c"}
 	tree := filepath.Join(components...)
 	s.MkdirAll(tree, os.FileMode(0755))
 	if err := s.Error(); err != nil {
 		t.Fatal(err)
 	}
 	defer os.RemoveAll(filepath.Join(here, "test"))

 	td := ""
 	for _, d := range components {
 		s.Pushd(d)
 		td = filepath.Join(td, d)
 		if got, want := getwd(t), td; got != want {
 			t.Errorf("got %v, want %v", got, want)
 		}
 	}
 	s.Done()
 	if got, want := getwd(t), here; got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}

 	s.Pushd("test").Pushd("a").Pushd("b")
 	if got, want := getwd(t), filepath.Join(here, "test", "a", "b"); got != want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 	err := s.Pushd("x").Done()
 	if err == nil {
 		t.Fatal(fmt.Errorf("expected an error"))
 	}
 	// Make sure the stack is unwound on error.
 	if got, want := getwd(t), here; got != want {
 		t.Errorf("got %v, want %v", got, want)
 		if err := os.Chdir(here); err != nil {
 			panic(fmt.Sprintf("failed to chdir back to %s", here))
 		}

 	}
 }

 // TODO(cnicolaou):
 // - tests for functions
 // - tests for terminating functions, make sure they clean up correctly.
	// Copyright 2015 The Vanadium 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 runutil_test

	import (
	"bytes"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"testing"
	"time"

	"v.io/jiri/runutil"
	)

	func rmLineNumbers(s string) string {
	re := regexp.MustCompile("(.\\.go):\\d+:(.)")
	return re.ReplaceAllString(s, "$1:-:$2")
	}

	func sanitizeTimestamps(s string) string {
	re := regexp.MustCompile(`\[(\d\d:\d\d:\d\d.\d\d)\]`)
	return re.ReplaceAllString(s, "[hh:mm:ss.xx]")
	}

	func ExampleSequence() {
	seq := runutil.NewSequence(nil, os.Stdin, ioutil.Discard, ioutil.Discard, false, false, true)
	err := seq.
	Capture(os.Stdout, nil).Run("echo", "a").
	Capture(os.Stdout, nil).Last("echo", "b")
	err = seq.
	Run("echo", "c").
	Run("xxxxxxx").
	Capture(os.Stdout, nil).Last("echo", "d")
	// Get rid of the line#s in the error output.
	fmt.Println(rmLineNumbers(err.Error()))
	// Output:
	// a
	// b
	// sequence_test.go:-: Run("xxxxxxx"): exec: "xxxxxxx": executable file not found in $PATH
	}

	// TestStdoutStderr exercises the various possible configurations for stdout and
	// stderr (via NewSequence, Opts, or Capture) as well as the verbose flag.
	func TestStdoutStderr(t *testing.T) {
	cwd, err := os.Getwd()
	if err != nil {
	t.Fatal(err)
	}
	dir := "Current Directory: " + cwd

	// Case 1: we only specify stdout/stderr at constructor time.
	//
	// Verbose mode: All the command's output and execution logging goes to
	// stdout, execution error messages to stderr.
	//
	// Non-Verbose mode: No stdout output; execution error messages to
	// stderr.
	for _, verbose := range []bool{false, true} {
	var cnstrStdout, cnstrStderr bytes.Buffer
	seq := runutil.NewSequence(nil, os.Stdin, &cnstrStdout, &cnstrStderr, false, false, verbose)
	seq.Run("bash", "-c", "echo a; echo b >&2").
	Timeout(time.Microsecond).
	Run("sleep", "10000")
	wantA, wantB := "", ""
	if verbose {
	// stdout, stderr output can be interleaved in arbitrary order.
	pre := `[hh:mm:ss.xx] >> bash -c "echo a; echo b >&2"
	[hh:mm:ss.xx] >> OK`
	post := `[hh:mm:ss.xx] >> sleep 10000
	[hh:mm:ss.xx] >> TIMED OUT
	`
	wantA = pre + `
	a
	b
	` + post
	wantB = pre + `
	b
	a
	` + post
	}
	if got := sanitizeTimestamps(cnstrStdout.String()); got != wantA && got != wantB {
	t.Errorf("verbose: %t, got %v, want either %v or %v", verbose, got, wantA, wantB)
	}
	if got, want := cnstrStderr.String(), "Waiting for command to exit: [\"sleep\" \"10000\"]\n"+dir+"\n"; want != got {
	t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
	}
	}

	// Case 2: we specify stdout/stderr at constructor time, and also via
	// Capture.
	//
	// Verbose mode: The command execution log goes to constructor stdout,
	// command execution errors go to constructor stderr, and the
	// stdout/stderr output from the command goes to capture stdout/stderr
	// respectively.
	//
	// Non-Verbose mode: The stdout/stderr output from the command goes to
	// capture stdout/stderr respectively. No command execution log, but
	// the command execution errors go to constructor stderr.
	for _, verbose := range []bool{false, true} {
	var cnstrStdout, cnstrStderr, captureStdout, captureStderr bytes.Buffer
	seq := runutil.NewSequence(nil, os.Stdin, &cnstrStdout, &cnstrStderr, false, false, verbose)
	seq.Capture(&captureStdout, &captureStderr).
	Run("bash", "-c", "echo a; echo b >&2").
	Timeout(time.Microsecond).
	Run("sleep", "10000")
	want := ""
	if verbose {
	want = `[hh:mm:ss.xx] >> bash -c "echo a; echo b >&2"
	[hh:mm:ss.xx] >> OK
	[hh:mm:ss.xx] >> sleep 10000
	[hh:mm:ss.xx] >> TIMED OUT
	`
	}
	if got := sanitizeTimestamps(cnstrStdout.String()); want != got {
	t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
	}
	if got, want := cnstrStderr.String(), "Waiting for command to exit: [\"sleep\" \"10000\"]\n"+dir+"\n"; want != got {
	t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
	}
	if got, want := captureStdout.String(), "a\n"; want != got {
	t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
	}
	if got, want := captureStderr.String(), "b\n"; want != got {
	t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
	}
	}

	// Case 3: we specify stdout/stderr at constructor and use nil
	// with Capture to verify that the constructor values are used.
	var cnstrStdout, cnstrStderr, captureStdout, captureStderr bytes.Buffer
	seq := runutil.NewSequence(nil, os.Stdin, &cnstrStdout, &cnstrStderr, false, false, false)
	err = seq.
	Capture(&captureStdout, nil).Run("bash", "-c", "echo a; echo b >&2").
	Capture(nil, &captureStderr).Last("bash", "-c", "echo c; echo d >&2")

	if got, want := cnstrStdout.String(), "c\n"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	if got, want := cnstrStderr.String(), "b\n"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	if got, want := captureStdout.String(), "a\n"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	if got, want := captureStderr.String(), "d\n"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	}

	func TestSequence(t *testing.T) {
	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
	if got, want := seq.Run("echo", "a").Done(), error(nil); got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	var out bytes.Buffer
	err := seq.
	Capture(&out, nil).Run("echo", "hello").
	Capture(&out, nil).Run("echo", "world").
	Done()
	if err != nil {
	t.Fatal(err)
	}
	if got, want := out.String(), "hello\nworld\n"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	out.Reset()
	env := map[string]string{
	"MYTEST": "hi",
	"MYTEST2": "there",
	}
	err = seq.
	Capture(&out, nil).Env(env).Run("sh", "-c", "echo $MYTEST").
	Env(env).Capture(&out, nil).Run("sh", "-c", "echo $MYTEST2").
	Done()
	if err != nil {
	t.Fatal(err)
	}
	if got, want := out.String(), "hi\nthere\n"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	out.Reset()
	err = seq.Run("./bound-to-fail", "fail").Done()
	if err == nil {
	t.Fatalf("should have experience an error")
	}
	if got, want := rmLineNumbers(err.Error()), "sequence_test.go:-: Run(\"./bound-to-fail\", \"fail\"): fork/exec ./bound-to-fail: no such file or directory"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	err = seq.
	Capture(&out, nil).Run("echo", "works, despite previous error").Done()
	if err != nil {
	t.Fatal(err)
	}
	if got, want := out.String(), "works, despite previous error\n"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	out.Reset()
	err = seq.Timeout(time.Second).Run("sleep", "10").Done()
	if got, want := rmLineNumbers(err.Error()), "sequence_test.go:-: Run(\"sleep\", \"10\"): command timed out"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	}

	// Test that modifiers don't get applied beyond the first invocation of Run.
	func TestSequenceModifiers(t *testing.T) {
	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
	var out bytes.Buffer
	env := map[string]string{
	"MYTEST": "hi",
	}
	err := seq.
	Capture(&out, nil).Env(env).Run("sh", "-c", "echo $MYTEST").
	Capture(&out, nil).Last("sh", "-c", "echo $MYTEST")
	if err != nil {
	t.Fatal(err)
	}
	if got, want := out.String(), "hi\n\n"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	out.Reset()

	err = seq.
	Capture(&out, nil).Run("echo", "hello").
	Run("echo", "world").
	Done()
	if err != nil {
	t.Fatal(err)
	}
	if got, want := out.String(), "hello\n"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	out.Reset()

	in := bytes.Buffer{}
	in.WriteString("Hello\n")
	in.WriteString("World\n")

	if err := seq.Read(&in).Capture(&out, nil).Last("sh", "-c", "read x; echo $x; read y; echo $y"); err != nil {
	t.Fatal(err)
	}
	if got, want := out.String(), "Hello\nWorld\n"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	}

	func TestSequenceOutputOnError(t *testing.T) {
	var out bytes.Buffer
	// Only the output from the command that generates an error is written
	// to stderr (i.e. out) when not in verbose mode.
	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, &out, false, false, false)
	err := seq.Run("sh", "-c", "echo not me").
	Run("sh", "-c", "echo ooh; echo ah; echo me; exit 1").
	Last("sh", "-c", "echo not me either")
	if err == nil {
	t.Errorf("expected an error")
	}
	if got, want := out.String(), "oh\nah\nme\n"; !strings.Contains(got, want) {
	t.Errorf("got %v doesn't contain %v", got, want)
	}
	if got, notWant := out.String(), "not me"; strings.Contains(got, notWant) {
	t.Errorf("got %v contains %v", got, notWant)
	}
	out.Reset()

	err = seq.Run("sh", "-c", "echo hard to not include me").
	Run("sh", "-c", "echo ooh; echo ah; echo me").
	Last("sh", "-c", "echo not me either")
	if err != nil {
	t.Error(err)
	}
	if got, want := len(out.String()), 0; got != want {
	t.Logf(out.String())
	t.Errorf("got %v, want %v", got, want)
	}
	out.Reset()

	err = seq.Last("sh", "-c", "echo should see an error; exit 1")
	if err == nil {
	t.Errorf("expected an error")
	}
	if got, want := out.String(), "should see an error"; !strings.Contains(got, want) {
	t.Errorf("got %v, want %v", got, want)
	}
	}

	type timestamped struct {
	times []time.Time
	data [][]byte
	}

	func (t *timestamped) Write(p []byte) (n int, err error) {
	t.times = append(t.times, time.Now())
	t.data = append(t.data, p)
	return len(p), nil
	}

	func TestSequenceStreaming(t *testing.T) {
	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
	ts := &timestamped{}
	err := seq.
	Capture(ts, nil).Last("sh", "-c", `
	for i in $(seq 1 5); do
	echo $i
	sleep 1
	done`)
	if err != nil {
	t.Fatal(err)
	}
	if got, want := len(ts.data), 5; got != want {
	t.Fatalf("got %v, want %v", got, want)
	}
	prev := ts.times[0]
	for _, nth := range ts.times[1:] {
	if nth.Sub(prev) < 500*time.Millisecond {
	t.Errorf("times %s and %s are too close together", nth, prev)
	}
	prev = nth
	}
	}

	func TestSequenceTerminatingMethod(t *testing.T) {
	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
	filename := "./test-file"
	fi, err := os.Create(filename)
	if err != nil {
	t.Fatal(err)
	}
	defer os.Remove(filename)
	data, err := seq.Capture(fi, nil).Run("echo", "aha").ReadFile(filename)
	if err != nil {
	t.Fatal(err)
	}
	if got, want := string(data), "aha\n"; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	}

	func getwd(t *testing.T) string {
	here, err := os.Getwd()
	if err != nil {
	t.Fatal(err)
	}
	return here
	}

	func TestSequencePushPop(t *testing.T) {
	here := getwd(t)
	s := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
	components := []string{here, "test", "a", "b", "c"}
	tree := filepath.Join(components...)
	s.MkdirAll(tree, os.FileMode(0755))
	if err := s.Error(); err != nil {
	t.Fatal(err)
	}
	defer os.RemoveAll(filepath.Join(here, "test"))

	td := ""
	for _, d := range components {
	s.Pushd(d)
	td = filepath.Join(td, d)
	if got, want := getwd(t), td; got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	}
	s.Done()
	if got, want := getwd(t), here; got != want {
	t.Errorf("got %v, want %v", got, want)
	}

	s.Pushd("test").Pushd("a").Pushd("b")
	if got, want := getwd(t), filepath.Join(here, "test", "a", "b"); got != want {
	t.Errorf("got %v, want %v", got, want)
	}
	err := s.Pushd("x").Done()
	if err == nil {
	t.Fatal(fmt.Errorf("expected an error"))
	}
	// Make sure the stack is unwound on error.
	if got, want := getwd(t), here; got != want {
	t.Errorf("got %v, want %v", got, want)
	if err := os.Chdir(here); err != nil {
	panic(fmt.Sprintf("failed to chdir back to %s", here))
	}

	}
	}

	// TODO(cnicolaou):
	// - tests for functions
	// - tests for terminating functions, make sure they clean up correctly.