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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 io_test
import (
"bytes"
. "io"
"strings"
"testing"
)
// An version of bytes.Buffer without ReadFrom and WriteTo
type Buffer struct {
bytes.Buffer
ReaderFrom // conflicts with and hides bytes.Buffer's ReaderFrom.
WriterTo // conflicts with and hides bytes.Buffer's WriterTo.
}
// Simple tests, primarily to verify the ReadFrom and WriteTo callouts inside Copy and CopyN.
func TestCopy(t *testing.T) {
rb := new(Buffer)
wb := new(Buffer)
rb.WriteString("hello, world.")
Copy(wb, rb)
if wb.String() != "hello, world." {
t.Errorf("Copy did not work properly")
}
}
func TestCopyReadFrom(t *testing.T) {
rb := new(Buffer)
wb := new(bytes.Buffer) // implements ReadFrom.
rb.WriteString("hello, world.")
Copy(wb, rb)
if wb.String() != "hello, world." {
t.Errorf("Copy did not work properly")
}
}
func TestCopyWriteTo(t *testing.T) {
rb := new(bytes.Buffer) // implements WriteTo.
wb := new(Buffer)
rb.WriteString("hello, world.")
Copy(wb, rb)
if wb.String() != "hello, world." {
t.Errorf("Copy did not work properly")
}
}
func TestCopyN(t *testing.T) {
rb := new(Buffer)
wb := new(Buffer)
rb.WriteString("hello, world.")
CopyN(wb, rb, 5)
if wb.String() != "hello" {
t.Errorf("CopyN did not work properly")
}
}
func TestCopyNReadFrom(t *testing.T) {
rb := new(Buffer)
wb := new(bytes.Buffer) // implements ReadFrom.
rb.WriteString("hello")
CopyN(wb, rb, 5)
if wb.String() != "hello" {
t.Errorf("CopyN did not work properly")
}
}
func TestCopyNWriteTo(t *testing.T) {
rb := new(bytes.Buffer) // implements WriteTo.
wb := new(Buffer)
rb.WriteString("hello, world.")
CopyN(wb, rb, 5)
if wb.String() != "hello" {
t.Errorf("CopyN did not work properly")
}
}
type noReadFrom struct {
w Writer
}
func (w *noReadFrom) Write(p []byte) (n int, err error) {
return w.w.Write(p)
}
func TestCopyNEOF(t *testing.T) {
// Test that EOF behavior is the same regardless of whether
// argument to CopyN has ReadFrom.
b := new(bytes.Buffer)
n, err := CopyN(&noReadFrom{b}, strings.NewReader("foo"), 3)
if n != 3 || err != nil {
t.Errorf("CopyN(noReadFrom, foo, 3) = %d, %v; want 3, nil", n, err)
}
n, err = CopyN(&noReadFrom{b}, strings.NewReader("foo"), 4)
if n != 3 || err != EOF {
t.Errorf("CopyN(noReadFrom, foo, 4) = %d, %v; want 3, EOF", n, err)
}
n, err = CopyN(b, strings.NewReader("foo"), 3) // b has read from
if n != 3 || err != nil {
t.Errorf("CopyN(bytes.Buffer, foo, 3) = %d, %v; want 3, nil", n, err)
}
n, err = CopyN(b, strings.NewReader("foo"), 4) // b has read from
if n != 3 || err != EOF {
t.Errorf("CopyN(bytes.Buffer, foo, 4) = %d, %v; want 3, EOF", n, err)
}
}
func TestReadAtLeast(t *testing.T) {
var rb bytes.Buffer
testReadAtLeast(t, &rb)
}
// A version of bytes.Buffer that returns n > 0, EOF on Read
// when the input is exhausted.
type dataAndEOFBuffer struct {
bytes.Buffer
}
func (r *dataAndEOFBuffer) Read(p []byte) (n int, err error) {
n, err = r.Buffer.Read(p)
if n > 0 && r.Buffer.Len() == 0 && err == nil {
err = EOF
}
return
}
func TestReadAtLeastWithDataAndEOF(t *testing.T) {
var rb dataAndEOFBuffer
testReadAtLeast(t, &rb)
}
func testReadAtLeast(t *testing.T, rb ReadWriter) {
rb.Write([]byte("0123"))
buf := make([]byte, 2)
n, err := ReadAtLeast(rb, buf, 2)
if err != nil {
t.Error(err)
}
n, err = ReadAtLeast(rb, buf, 4)
if err != ErrShortBuffer {
t.Errorf("expected ErrShortBuffer got %v", err)
}
if n != 0 {
t.Errorf("expected to have read 0 bytes, got %v", n)
}
n, err = ReadAtLeast(rb, buf, 1)
if err != nil {
t.Error(err)
}
if n != 2 {
t.Errorf("expected to have read 2 bytes, got %v", n)
}
n, err = ReadAtLeast(rb, buf, 2)
if err != EOF {
t.Errorf("expected EOF, got %v", err)
}
if n != 0 {
t.Errorf("expected to have read 0 bytes, got %v", n)
}
rb.Write([]byte("4"))
n, err = ReadAtLeast(rb, buf, 2)
if err != ErrUnexpectedEOF {
t.Errorf("expected ErrUnexpectedEOF, got %v", err)
}
if n != 1 {
t.Errorf("expected to have read 1 bytes, got %v", n)
}
}
func TestTeeReader(t *testing.T) {
src := []byte("hello, world")
dst := make([]byte, len(src))
rb := bytes.NewBuffer(src)
wb := new(bytes.Buffer)
r := TeeReader(rb, wb)
if n, err := ReadFull(r, dst); err != nil || n != len(src) {
t.Fatalf("ReadFull(r, dst) = %d, %v; want %d, nil", n, err, len(src))
}
if !bytes.Equal(dst, src) {
t.Errorf("bytes read = %q want %q", dst, src)
}
if !bytes.Equal(wb.Bytes(), src) {
t.Errorf("bytes written = %q want %q", wb.Bytes(), src)
}
if n, err := r.Read(dst); n != 0 || err != EOF {
t.Errorf("r.Read at EOF = %d, %v want 0, EOF", n, err)
}
rb = bytes.NewBuffer(src)
pr, pw := Pipe()
pr.Close()
r = TeeReader(rb, pw)
if n, err := ReadFull(r, dst); n != 0 || err != ErrClosedPipe {
t.Errorf("closed tee: ReadFull(r, dst) = %d, %v; want 0, EPIPE", n, err)
}
}