Subversion Repositories openrisc

// 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)
        }
}