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"
  10         "io/ioutil"
  11         "strings"
  12         "testing"
  13 )
  14
  15 type testpair struct {
  16         decoded, encoded string
  17 }
  18
  19 var pairs = []testpair{
  20         // Encode returns 0 when len(src) is 0
  21         {
  22                 "",
  23                 "",
  24         },
  25         // Wikipedia example
  26         {
  27                 "Man is distinguished, not only by his reason, but by this singular passion from " +
  28                         "other animals, which is a lust of the mind, that by a perseverance of delight in " +
  29                         "the continued and indefatigable generation of knowledge, exceeds the short " +
  30                         "vehemence of any carnal pleasure.",
  31                 "9jqo^BlbD-BleB1DJ+*+F(f,q/0JhKF<GL>Cj@.4Gp$d7F!,L7@<6@)/0JDEF<G%<+EV:2F!,\n" +
  32                         "O<DJ+*.@<*K0@<6L(Df-\\0Ec5e;DffZ(EZee.Bl.9pF\"AGXBPCsi+DGm>@3BB/F*&OCAfu2/AKY\n" +
  33                         "i(DIb:@FD,*)+C]U=@3BN#EcYf8ATD3s@q?d$AftVqCh[NqF<G:8+EV:.+Cf>-FD5W8ARlolDIa\n" +
  34                         "l(DId<j@<?3r@:F%a+D58'ATD4$Bl@l3De:,-DJs`8ARoFb/0JMK@qB4^F!,R<AKZ&-DfTqBG%G\n" +
  35                         ">uD.RTpAKYo'+CT/5+Cei#DII?(E,9)oF*2M7/c\n",
  36         },
  37         // Special case when shortening !!!!! to z.
  38         {
  39                 "\000\000\000\000",
  40                 "z",
  41         },
  42 }
  43
  44 var bigtest = pairs[len(pairs)-1]
  45
  46 func testEqual(t *testing.T, msg string, args ...interface{}) bool {
  47         if args[len(args)-2] != args[len(args)-1] {
  48                 t.Errorf(msg, args...)
  49                 return false
  50         }
  51         return true
  52 }
  53
  54 func strip85(s string) string {
  55         t := make([]byte, len(s))
  56         w := 0
  57         for r := 0; r < len(s); r++ {
  58                 c := s[r]
  59                 if c > ' ' {
  60                         t[w] = c
  61                         w++
  62                 }
  63         }
  64         return string(t[0:w])
  65 }
  66
  67 func TestEncode(t *testing.T) {
  68         for _, p := range pairs {
  69                 buf := make([]byte, MaxEncodedLen(len(p.decoded)))
  70                 n := Encode(buf, []byte(p.decoded))
  71                 buf = buf[0:n]
  72                 testEqual(t, "Encode(%q) = %q, want %q", p.decoded, strip85(string(buf)), strip85(p.encoded))
  73         }
  74 }
  75
  76 func TestEncoder(t *testing.T) {
  77         for _, p := range pairs {
  78                 bb := &bytes.Buffer{}
  79                 encoder := NewEncoder(bb)
  80                 encoder.Write([]byte(p.decoded))
  81                 encoder.Close()
  82                 testEqual(t, "Encode(%q) = %q, want %q", p.decoded, strip85(bb.String()), strip85(p.encoded))
  83         }
  84 }
  85
  86 func TestEncoderBuffering(t *testing.T) {
  87         input := []byte(bigtest.decoded)
  88         for bs := 1; bs <= 12; bs++ {
  89                 bb := &bytes.Buffer{}
  90                 encoder := NewEncoder(bb)
  91                 for pos := 0; pos < len(input); pos += bs {
  92                         end := pos + bs
  93                         if end > len(input) {
  94                                 end = len(input)
  95                         }
  96                         n, err := encoder.Write(input[pos:end])
  97                         testEqual(t, "Write(%q) gave error %v, want %v", input[pos:end], err, error(nil))
  98                         testEqual(t, "Write(%q) gave length %v, want %v", input[pos:end], n, end-pos)
  99                 }
 100                 err := encoder.Close()
 101                 testEqual(t, "Close gave error %v, want %v", err, error(nil))
 102                 testEqual(t, "Encoding/%d of %q = %q, want %q", bs, bigtest.decoded, strip85(bb.String()), strip85(bigtest.encoded))
 103         }
 104 }
 105
 106 func TestDecode(t *testing.T) {
 107         for _, p := range pairs {
 108                 dbuf := make([]byte, 4*len(p.encoded))
 109                 ndst, nsrc, err := Decode(dbuf, []byte(p.encoded), true)
 110                 testEqual(t, "Decode(%q) = error %v, want %v", p.encoded, err, error(nil))
 111                 testEqual(t, "Decode(%q) = nsrc %v, want %v", p.encoded, nsrc, len(p.encoded))
 112                 testEqual(t, "Decode(%q) = ndst %v, want %v", p.encoded, ndst, len(p.decoded))
 113                 testEqual(t, "Decode(%q) = %q, want %q", p.encoded, string(dbuf[0:ndst]), p.decoded)
 114         }
 115 }
 116
 117 func TestDecoder(t *testing.T) {
 118         for _, p := range pairs {
 119                 decoder := NewDecoder(strings.NewReader(p.encoded))
 120                 dbuf, err := ioutil.ReadAll(decoder)
 121                 if err != nil {
 122                         t.Fatal("Read failed", err)
 123                 }
 124                 testEqual(t, "Read from %q = length %v, want %v", p.encoded, len(dbuf), len(p.decoded))
 125                 testEqual(t, "Decoding of %q = %q, want %q", p.encoded, string(dbuf), p.decoded)
 126                 if err != nil {
 127                         testEqual(t, "Read from %q = %v, want %v", p.encoded, err, io.EOF)
 128                 }
 129         }
 130 }
 131
 132 func TestDecoderBuffering(t *testing.T) {
 133         for bs := 1; bs <= 12; bs++ {
 134                 decoder := NewDecoder(strings.NewReader(bigtest.encoded))
 135                 buf := make([]byte, len(bigtest.decoded)+12)
 136                 var total int
 137                 for total = 0; total < len(bigtest.decoded); {
 138                         n, err := decoder.Read(buf[total : total+bs])
 139                         testEqual(t, "Read from %q at pos %d = %d, %v, want _, %v", bigtest.encoded, total, n, err, error(nil))
 140                         total += n
 141                 }
 142                 testEqual(t, "Decoding/%d of %q = %q, want %q", bs, bigtest.encoded, string(buf[0:total]), bigtest.decoded)
 143         }
 144 }
 145
 146 func TestDecodeCorrupt(t *testing.T) {
 147         type corrupt struct {
 148                 e string
 149                 p int
 150         }
 151         examples := []corrupt{
 152                 {"v", 0},
 153                 {"!z!!!!!!!!!", 1},
 154         }
 155
 156         for _, e := range examples {
 157                 dbuf := make([]byte, 4*len(e.e))
 158                 _, _, err := Decode(dbuf, []byte(e.e), true)
 159                 switch err := err.(type) {
 160                 case CorruptInputError:
 161                         testEqual(t, "Corruption in %q at offset %v, want %v", e.e, int(err), e.p)
 162                 default:
 163                         t.Error("Decoder failed to detect corruption in", e)
 164                 }
 165         }
 166 }
 167
 168 func TestBig(t *testing.T) {
 169         n := 3*1000 + 1
 170         raw := make([]byte, n)
 171         const alpha = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
 172         for i := 0; i < n; i++ {
 173                 raw[i] = alpha[i%len(alpha)]
 174         }
 175         encoded := new(bytes.Buffer)
 176         w := NewEncoder(encoded)
 177         nn, err := w.Write(raw)
 178         if nn != n || err != nil {
 179                 t.Fatalf("Encoder.Write(raw) = %d, %v want %d, nil", nn, err, n)
 180         }
 181         err = w.Close()
 182         if err != nil {
 183                 t.Fatalf("Encoder.Close() = %v want nil", err)
 184         }
 185         decoded, err := ioutil.ReadAll(NewDecoder(encoded))
 186         if err != nil {
 187                 t.Fatalf("io.ReadAll(NewDecoder(...)): %v", err)
 188         }
 189
 190         if !bytes.Equal(raw, decoded) {
 191                 var i int
 192                 for i = 0; i < len(decoded) && i < len(raw); i++ {
 193                         if decoded[i] != raw[i] {
 194                                 break
 195                         }
 196                 }
 197                 t.Errorf("Decode(Encode(%d-byte string)) failed at offset %d", n, i)
 198         }
 199 }
 200
 201 func TestDecoderInternalWhitespace(t *testing.T) {
 202         s := strings.Repeat(" ", 2048) + "z"
 203         decoded, err := ioutil.ReadAll(NewDecoder(strings.NewReader(s)))
 204         if err != nil {
 205                 t.Errorf("Decode gave error %v", err)
 206         }
 207         if want := []byte("\000\000\000\000"); !bytes.Equal(want, decoded) {
 208                 t.Errorf("Decode failed: got %v, want %v", decoded, want)
 209         }
 210 }