libgo/go/io/multi_test.go

   1 // Copyright 2010 The Go Authors.  All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 package io_test
   6
   7 import (
   8         "bytes"
   9         "crypto/sha1"
  10         "fmt"
  11         . "io"
  12         "strings"
  13         "testing"
  14 )
  15
  16 func TestMultiReader(t *testing.T) {
  17         var mr Reader
  18         var buf []byte
  19         nread := 0
  20         withFooBar := func(tests func()) {
  21                 r1 := strings.NewReader("foo ")
  22                 r2 := strings.NewReader("")
  23                 r3 := strings.NewReader("bar")
  24                 mr = MultiReader(r1, r2, r3)
  25                 buf = make([]byte, 20)
  26                 tests()
  27         }
  28         expectRead := func(size int, expected string, eerr error) {
  29                 nread++
  30                 n, gerr := mr.Read(buf[0:size])
  31                 if n != len(expected) {
  32                         t.Errorf("#%d, expected %d bytes; got %d",
  33                                 nread, len(expected), n)
  34                 }
  35                 got := string(buf[0:n])
  36                 if got != expected {
  37                         t.Errorf("#%d, expected %q; got %q",
  38                                 nread, expected, got)
  39                 }
  40                 if gerr != eerr {
  41                         t.Errorf("#%d, expected error %v; got %v",
  42                                 nread, eerr, gerr)
  43                 }
  44                 buf = buf[n:]
  45         }
  46         withFooBar(func() {
  47                 expectRead(2, "fo", nil)
  48                 expectRead(5, "o ", nil)
  49                 expectRead(5, "bar", nil)
  50                 expectRead(5, "", EOF)
  51         })
  52         withFooBar(func() {
  53                 expectRead(4, "foo ", nil)
  54                 expectRead(1, "b", nil)
  55                 expectRead(3, "ar", nil)
  56                 expectRead(1, "", EOF)
  57         })
  58         withFooBar(func() {
  59                 expectRead(5, "foo ", nil)
  60         })
  61 }
  62
  63 func TestMultiWriter(t *testing.T) {
  64         sha1 := sha1.New()
  65         sink := new(bytes.Buffer)
  66         mw := MultiWriter(sha1, sink)
  67
  68         sourceString := "My input text."
  69         source := strings.NewReader(sourceString)
  70         written, err := Copy(mw, source)
  71
  72         if written != int64(len(sourceString)) {
  73                 t.Errorf("short write of %d, not %d", written, len(sourceString))
  74         }
  75
  76         if err != nil {
  77                 t.Errorf("unexpected error: %v", err)
  78         }
  79
  80         sha1hex := fmt.Sprintf("%x", sha1.Sum(nil))
  81         if sha1hex != "01cb303fa8c30a64123067c5aa6284ba7ec2d31b" {
  82                 t.Error("incorrect sha1 value")
  83         }
  84
  85         if sink.String() != sourceString {
  86                 t.Errorf("expected %q; got %q", sourceString, sink.String())
  87         }
  88 }