package stdcopy
import (
"bytes"
"errors"
"io"
"io/ioutil"
"strings"
"testing"
)
func TestNewStdWriter(t *testing.T) {
writer := NewStdWriter(ioutil.Discard, Stdout)
if writer == nil {
t.Fatalf("NewStdWriter with an invalid StdType should not return nil.")
}
}
func TestWriteWithUninitializedStdWriter(t *testing.T) {
writer := stdWriter{
Writer: nil,
prefix: byte(Stdout),
}
n, err := writer.Write([]byte("Something here"))
if n != 0 || err == nil {
t.Fatalf("Should fail when given an uncomplete or uninitialized StdWriter")
}
}
func TestWriteWithNilBytes(t *testing.T) {
writer := NewStdWriter(ioutil.Discard, Stdout)
n, err := writer.Write(nil)
if err != nil {
t.Fatalf("Shouldn't have fail when given no data")
}
if n > 0 {
t.Fatalf("Write should have written 0 byte, but has written %d", n)
}
}
func TestWrite(t *testing.T) {
writer := NewStdWriter(ioutil.Discard, Stdout)
data := []byte("Test StdWrite.Write")
n, err := writer.Write(data)
if err != nil {
t.Fatalf("Error while writing with StdWrite")
}
if n != len(data) {
t.Fatalf("Write should have written %d byte but wrote %d.", len(data), n)
}
}
type errWriter struct {
n int
err error
}
func (f *errWriter) Write(buf []byte) (int, error) {
return f.n, f.err
}
func TestWriteWithWriterError(t *testing.T) {
expectedError := errors.New("expected")
expectedReturnedBytes := 10
writer := NewStdWriter(&errWriter{
n: stdWriterPrefixLen + expectedReturnedBytes,
err: expectedError}, Stdout)
data := []byte("This won't get written, sigh")
n, err := writer.Write(data)
if err != expectedError {
t.Fatalf("Didn't get expected error.")
}
if n != expectedReturnedBytes {
t.Fatalf("Didn't get expected written bytes %d, got %d.",
expectedReturnedBytes, n)
}
}
func TestWriteDoesNotReturnNegativeWrittenBytes(t *testing.T) {
writer := NewStdWriter(&errWriter{n: -1}, Stdout)
data := []byte("This won't get written, sigh")
actual, _ := writer.Write(data)
if actual != 0 {
t.Fatalf("Expected returned written bytes equal to 0, got %d", actual)
}
}
func getSrcBuffer(stdOutBytes, stdErrBytes []byte) (buffer *bytes.Buffer, err error) {
buffer = new(bytes.Buffer)
dstOut := NewStdWriter(buffer, Stdout)
_, err = dstOut.Write(stdOutBytes)
if err != nil {
return
}
dstErr := NewStdWriter(buffer, Stderr)
_, err = dstErr.Write(stdErrBytes)
return
}
func TestStdCopyWriteAndRead(t *testing.T) {
stdOutBytes := []byte(strings.Repeat("o", startingBufLen))
stdErrBytes := []byte(strings.Repeat("e", startingBufLen))
buffer, err := getSrcBuffer(stdOutBytes, stdErrBytes)
if err != nil {
t.Fatal(err)
}
written, err := StdCopy(ioutil.Discard, ioutil.Discard, buffer)
if err != nil {
t.Fatal(err)
}
expectedTotalWritten := len(stdOutBytes) + len(stdErrBytes)
if written != int64(expectedTotalWritten) {
t.Fatalf("Expected to have total of %d bytes written, got %d", expectedTotalWritten, written)
}
}
type customReader struct {
n int
err error
totalCalls int
correctCalls int
src *bytes.Buffer
}
func (f *customReader) Read(buf []byte) (int, error) {
f.totalCalls++
if f.totalCalls <= f.correctCalls {
return f.src.Read(buf)
}
return f.n, f.err
}
func TestStdCopyReturnsErrorReadingHeader(t *testing.T) {
expectedError := errors.New("error")
reader := &customReader{
err: expectedError}
written, err := StdCopy(ioutil.Discard, ioutil.Discard, reader)
if written != 0 {
t.Fatalf("Expected 0 bytes read, got %d", written)
}
if err != expectedError {
t.Fatalf("Didn't get expected error")
}
}
func TestStdCopyReturnsErrorReadingFrame(t *testing.T) {
expectedError := errors.New("error")
stdOutBytes := []byte(strings.Repeat("o", startingBufLen))
stdErrBytes := []byte(strings.Repeat("e", startingBufLen))
buffer, err := getSrcBuffer(stdOutBytes, stdErrBytes)
if err != nil {
t.Fatal(err)
}
reader := &customReader{
correctCalls: 1,
n: stdWriterPrefixLen + 1,
err: expectedError,
src: buffer}
written, err := StdCopy(ioutil.Discard, ioutil.Discard, reader)
if written != 0 {
t.Fatalf("Expected 0 bytes read, got %d", written)
}
if err != expectedError {
t.Fatalf("Didn't get expected error")
}
}
func TestStdCopyDetectsCorruptedFrame(t *testing.T) {
stdOutBytes := []byte(strings.Repeat("o", startingBufLen))
stdErrBytes := []byte(strings.Repeat("e", startingBufLen))
buffer, err := getSrcBuffer(stdOutBytes, stdErrBytes)
if err != nil {
t.Fatal(err)
}
reader := &customReader{
correctCalls: 1,
n: stdWriterPrefixLen + 1,
err: io.EOF,
src: buffer}
written, err := StdCopy(ioutil.Discard, ioutil.Discard, reader)
if written != startingBufLen {
t.Fatalf("Expected %d bytes read, got %d", startingBufLen, written)
}
if err != nil {
t.Fatal("Didn't get nil error")
}
}
func TestStdCopyWithInvalidInputHeader(t *testing.T) {
dstOut := NewStdWriter(ioutil.Discard, Stdout)
dstErr := NewStdWriter(ioutil.Discard, Stderr)
src := strings.NewReader("Invalid input")
_, err := StdCopy(dstOut, dstErr, src)
if err == nil {
t.Fatal("StdCopy with invalid input header should fail.")
}
}
func TestStdCopyWithCorruptedPrefix(t *testing.T) {
data := []byte{0x01, 0x02, 0x03}
src := bytes.NewReader(data)
written, err := StdCopy(nil, nil, src)
if err != nil {
t.Fatalf("StdCopy should not return an error with corrupted prefix.")
}
if written != 0 {
t.Fatalf("StdCopy should have written 0, but has written %d", written)
}
}
func TestStdCopyReturnsWriteErrors(t *testing.T) {
stdOutBytes := []byte(strings.Repeat("o", startingBufLen))
stdErrBytes := []byte(strings.Repeat("e", startingBufLen))
buffer, err := getSrcBuffer(stdOutBytes, stdErrBytes)
if err != nil {
t.Fatal(err)
}
expectedError := errors.New("expected")
dstOut := &errWriter{err: expectedError}
written, err := StdCopy(dstOut, ioutil.Discard, buffer)
if written != 0 {
t.Fatalf("StdCopy should have written 0, but has written %d", written)
}
if err != expectedError {
t.Fatalf("Didn't get expected error, got %v", err)
}
}
func TestStdCopyDetectsNotFullyWrittenFrames(t *testing.T) {
stdOutBytes := []byte(strings.Repeat("o", startingBufLen))
stdErrBytes := []byte(strings.Repeat("e", startingBufLen))
buffer, err := getSrcBuffer(stdOutBytes, stdErrBytes)
if err != nil {
t.Fatal(err)
}
dstOut := &errWriter{n: startingBufLen - 10}
written, err := StdCopy(dstOut, ioutil.Discard, buffer)
if written != 0 {
t.Fatalf("StdCopy should have return 0 written bytes, but returned %d", written)
}
if err != io.ErrShortWrite {
t.Fatalf("Didn't get expected io.ErrShortWrite error")
}
}
// TestStdCopyReturnsErrorFromSystem tests that StdCopy correctly returns an
// error, when that error is muxed into the Systemerr stream.
func TestStdCopyReturnsErrorFromSystem(t *testing.T) {
// write in the basic messages, just so there's some fluff in there
stdOutBytes := []byte(strings.Repeat("o", startingBufLen))
stdErrBytes := []byte(strings.Repeat("e", startingBufLen))
buffer, err := getSrcBuffer(stdOutBytes, stdErrBytes)
if err != nil {
t.Fatal(err)
}
// add in an error message on the Systemerr stream
systemErrBytes := []byte(strings.Repeat("S", startingBufLen))
systemWriter := NewStdWriter(buffer, Systemerr)
_, err = systemWriter.Write(systemErrBytes)
if err != nil {
t.Fatal(err)
}
// now copy and demux. we should expect an error containing the string we
// wrote out
_, err = StdCopy(ioutil.Discard, ioutil.Discard, buffer)
if err == nil {
t.Fatal("expected error, got none")
}
if !strings.Contains(err.Error(), string(systemErrBytes)) {
t.Fatal("expected error to contain message")
}
}
func BenchmarkWrite(b *testing.B) {
w := NewStdWriter(ioutil.Discard, Stdout)
data := []byte("Test line for testing stdwriter performance\n")
data = bytes.Repeat(data, 100)
b.SetBytes(int64(len(data)))
b.ResetTimer()
for i := 0; i < b.N; i++ {
if _, err := w.Write(data); err != nil {
b.Fatal(err)
}
}
}