libgo/go/encoding/ascii85/ascii85_test.go

   1 // Copyright 2009 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 ascii85
   6
   7 import (
   8         "bytes"
   9         "io/ioutil"
  10         "os"
  11         "testing"
  12 )
  13
  14 type testpair struct {
  15         decoded, encoded string
  16 }
  17
  18 var pairs = []testpair{
  19         // Wikipedia example
  20         {
  21                 "Man is distinguished, not only by his reason, but by this singular passion from " +
  22                         "other animals, which is a lust of the mind, that by a perseverance of delight in " +
  23                         "the continued and indefatigable generation of knowledge, exceeds the short " +
  24                         "vehemence of any carnal pleasure.",
  25                 "9jqo^BlbD-BleB1DJ+*+F(f,q/0JhKF<GL>Cj@.4Gp$d7F!,L7@<6@)/0JDEF<G%<+EV:2F!,\n" +
  26                         "O<DJ+*.@<*K0@<6L(Df-\\0Ec5e;DffZ(EZee.Bl.9pF\"AGXBPCsi+DGm>@3BB/F*&OCAfu2/AKY\n" +
  27                         "i(DIb:@FD,*)+C]U=@3BN#EcYf8ATD3s@q?d$AftVqCh[NqF<G:8+EV:.+Cf>-FD5W8ARlolDIa\n" +
  28                         "l(DId<j@<?3r@:F%a+D58'ATD4$Bl@l3De:,-DJs`8ARoFb/0JMK@qB4^F!,R<AKZ&-DfTqBG%G\n" +
  29                         ">uD.RTpAKYo'+CT/5+Cei#DII?(E,9)oF*2M7/c\n",
  30         },
  31 }
  32
  33 var bigtest = pairs[len(pairs)-1]
  34
  35 func testEqual(t *testing.T, msg string, args ...interface{}) bool {
  36         if args[len(args)-2] != args[len(args)-1] {
  37                 t.Errorf(msg, args...)
  38                 return false
  39         }
  40         return true
  41 }
  42
  43 func strip85(s string) string {
  44         t := make([]byte, len(s))
  45         w := 0
  46         for r := 0; r < len(s); r++ {
  47                 c := s[r]
  48                 if c > ' ' {
  49                         t[w] = c
  50                         w++
  51                 }
  52         }
  53         return string(t[0:w])
  54 }
  55
  56 func TestEncode(t *testing.T) {
  57         for _, p := range pairs {
  58                 buf := make([]byte, MaxEncodedLen(len(p.decoded)))
  59                 n := Encode(buf, []byte(p.decoded))
  60                 buf = buf[0:n]
  61                 testEqual(t, "Encode(%q) = %q, want %q", p.decoded, strip85(string(buf)), strip85(p.encoded))
  62         }
  63 }
  64
  65 func TestEncoder(t *testing.T) {
  66         for _, p := range pairs {
  67                 bb := &bytes.Buffer{}
  68                 encoder := NewEncoder(bb)
  69                 encoder.Write([]byte(p.decoded))
  70                 encoder.Close()
  71                 testEqual(t, "Encode(%q) = %q, want %q", p.decoded, strip85(bb.String()), strip85(p.encoded))
  72         }
  73 }
  74
  75 func TestEncoderBuffering(t *testing.T) {
  76         input := []byte(bigtest.decoded)
  77         for bs := 1; bs <= 12; bs++ {
  78                 bb := &bytes.Buffer{}
  79                 encoder := NewEncoder(bb)
  80                 for pos := 0; pos < len(input); pos += bs {
  81                         end := pos + bs
  82                         if end > len(input) {
  83                                 end = len(input)
  84                         }
  85                         n, err := encoder.Write(input[pos:end])
  86                         testEqual(t, "Write(%q) gave error %v, want %v", input[pos:end], err, os.Error(nil))
  87                         testEqual(t, "Write(%q) gave length %v, want %v", input[pos:end], n, end-pos)
  88                 }
  89                 err := encoder.Close()
  90                 testEqual(t, "Close gave error %v, want %v", err, os.Error(nil))
  91                 testEqual(t, "Encoding/%d of %q = %q, want %q", bs, bigtest.decoded, strip85(bb.String()), strip85(bigtest.encoded))
  92         }
  93 }
  94
  95 func TestDecode(t *testing.T) {
  96         for _, p := range pairs {
  97                 dbuf := make([]byte, 4*len(p.encoded))
  98                 ndst, nsrc, err := Decode(dbuf, []byte(p.encoded), true)
  99                 testEqual(t, "Decode(%q) = error %v, want %v", p.encoded, err, os.Error(nil))
 100                 testEqual(t, "Decode(%q) = nsrc %v, want %v", p.encoded, nsrc, len(p.encoded))
 101                 testEqual(t, "Decode(%q) = ndst %v, want %v", p.encoded, ndst, len(p.decoded))
 102                 testEqual(t, "Decode(%q) = %q, want %q", p.encoded, string(dbuf[0:ndst]), p.decoded)
 103         }
 104 }
 105
 106 func TestDecoder(t *testing.T) {
 107         for _, p := range pairs {
 108                 decoder := NewDecoder(bytes.NewBufferString(p.encoded))
 109                 dbuf, err := ioutil.ReadAll(decoder)
 110                 if err != nil {
 111                         t.Fatal("Read failed", err)
 112                 }
 113                 testEqual(t, "Read from %q = length %v, want %v", p.encoded, len(dbuf), len(p.decoded))
 114                 testEqual(t, "Decoding of %q = %q, want %q", p.encoded, string(dbuf), p.decoded)
 115                 if err != nil {
 116                         testEqual(t, "Read from %q = %v, want %v", p.encoded, err, os.EOF)
 117                 }
 118         }
 119 }
 120
 121 func TestDecoderBuffering(t *testing.T) {
 122         for bs := 1; bs <= 12; bs++ {
 123                 decoder := NewDecoder(bytes.NewBufferString(bigtest.encoded))
 124                 buf := make([]byte, len(bigtest.decoded)+12)
 125                 var total int
 126                 for total = 0; total < len(bigtest.decoded); {
 127                         n, err := decoder.Read(buf[total : total+bs])
 128                         testEqual(t, "Read from %q at pos %d = %d, %v, want _, %v", bigtest.encoded, total, n, err, os.Error(nil))
 129                         total += n
 130                 }
 131                 testEqual(t, "Decoding/%d of %q = %q, want %q", bs, bigtest.encoded, string(buf[0:total]), bigtest.decoded)
 132         }
 133 }
 134
 135 func TestDecodeCorrupt(t *testing.T) {
 136         type corrupt struct {
 137                 e string
 138                 p int
 139         }
 140         examples := []corrupt{
 141                 {"v", 0},
 142                 {"!z!!!!!!!!!", 1},
 143         }
 144
 145         for _, e := range examples {
 146                 dbuf := make([]byte, 4*len(e.e))
 147                 _, _, err := Decode(dbuf, []byte(e.e), true)
 148                 switch err := err.(type) {
 149                 case CorruptInputError:
 150                         testEqual(t, "Corruption in %q at offset %v, want %v", e.e, int(err), e.p)
 151                 default:
 152                         t.Error("Decoder failed to detect corruption in", e)
 153                 }
 154         }
 155 }
 156
 157 func TestBig(t *testing.T) {
 158         n := 3*1000 + 1
 159         raw := make([]byte, n)
 160         const alpha = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
 161         for i := 0; i < n; i++ {
 162                 raw[i] = alpha[i%len(alpha)]
 163         }
 164         encoded := new(bytes.Buffer)
 165         w := NewEncoder(encoded)
 166         nn, err := w.Write(raw)
 167         if nn != n || err != nil {
 168                 t.Fatalf("Encoder.Write(raw) = %d, %v want %d, nil", nn, err, n)
 169         }
 170         err = w.Close()
 171         if err != nil {
 172                 t.Fatalf("Encoder.Close() = %v want nil", err)
 173         }
 174         decoded, err := ioutil.ReadAll(NewDecoder(encoded))
 175         if err != nil {
 176                 t.Fatalf("io.ReadAll(NewDecoder(...)): %v", err)
 177         }
 178
 179         if !bytes.Equal(raw, decoded) {
 180                 var i int
 181                 for i = 0; i < len(decoded) && i < len(raw); i++ {
 182                         if decoded[i] != raw[i] {
 183                                 break
 184                         }
 185                 }
 186                 t.Errorf("Decode(Encode(%d-byte string)) failed at offset %d", n, i)
 187         }
 188 }