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      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 zlib
      6 
      7 import (
      8 	"bytes"
      9 	"io"
     10 	"testing"
     11 )
     12 
     13 type zlibTest struct {
     14 	desc       string
     15 	raw        string
     16 	compressed []byte
     17 	dict       []byte
     18 	err        error
     19 }
     20 
     21 // Compare-to-golden test data was generated by the ZLIB example program at
     22 // http://www.zlib.net/zpipe.c
     23 
     24 var zlibTests = []zlibTest{
     25 	{
     26 		"empty",
     27 		"",
     28 		[]byte{0x78, 0x9c, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01},
     29 		nil,
     30 		nil,
     31 	},
     32 	{
     33 		"goodbye",
     34 		"goodbye, world",
     35 		[]byte{
     36 			0x78, 0x9c, 0x4b, 0xcf, 0xcf, 0x4f, 0x49, 0xaa,
     37 			0x4c, 0xd5, 0x51, 0x28, 0xcf, 0x2f, 0xca, 0x49,
     38 			0x01, 0x00, 0x28, 0xa5, 0x05, 0x5e,
     39 		},
     40 		nil,
     41 		nil,
     42 	},
     43 	{
     44 		"bad header",
     45 		"",
     46 		[]byte{0x78, 0x9f, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01},
     47 		nil,
     48 		ErrHeader,
     49 	},
     50 	{
     51 		"bad checksum",
     52 		"",
     53 		[]byte{0x78, 0x9c, 0x03, 0x00, 0x00, 0x00, 0x00, 0xff},
     54 		nil,
     55 		ErrChecksum,
     56 	},
     57 	{
     58 		"not enough data",
     59 		"",
     60 		[]byte{0x78, 0x9c, 0x03, 0x00, 0x00, 0x00},
     61 		nil,
     62 		io.ErrUnexpectedEOF,
     63 	},
     64 	{
     65 		"excess data is silently ignored",
     66 		"",
     67 		[]byte{
     68 			0x78, 0x9c, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01,
     69 			0x78, 0x9c, 0xff,
     70 		},
     71 		nil,
     72 		nil,
     73 	},
     74 	{
     75 		"dictionary",
     76 		"Hello, World!\n",
     77 		[]byte{
     78 			0x78, 0xbb, 0x1c, 0x32, 0x04, 0x27, 0xf3, 0x00,
     79 			0xb1, 0x75, 0x20, 0x1c, 0x45, 0x2e, 0x00, 0x24,
     80 			0x12, 0x04, 0x74,
     81 		},
     82 		[]byte{
     83 			0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x57, 0x6f, 0x72, 0x6c, 0x64, 0x0a,
     84 		},
     85 		nil,
     86 	},
     87 	{
     88 		"wrong dictionary",
     89 		"",
     90 		[]byte{
     91 			0x78, 0xbb, 0x1c, 0x32, 0x04, 0x27, 0xf3, 0x00,
     92 			0xb1, 0x75, 0x20, 0x1c, 0x45, 0x2e, 0x00, 0x24,
     93 			0x12, 0x04, 0x74,
     94 		},
     95 		[]byte{
     96 			0x48, 0x65, 0x6c, 0x6c,
     97 		},
     98 		ErrDictionary,
     99 	},
    100 }
    101 
    102 func TestDecompressor(t *testing.T) {
    103 	b := new(bytes.Buffer)
    104 	for _, tt := range zlibTests {
    105 		in := bytes.NewReader(tt.compressed)
    106 		zlib, err := NewReaderDict(in, tt.dict)
    107 		if err != nil {
    108 			if err != tt.err {
    109 				t.Errorf("%s: NewReader: %s", tt.desc, err)
    110 			}
    111 			continue
    112 		}
    113 		defer zlib.Close()
    114 		b.Reset()
    115 		n, err := io.Copy(b, zlib)
    116 		if err != nil {
    117 			if err != tt.err {
    118 				t.Errorf("%s: io.Copy: %v want %v", tt.desc, err, tt.err)
    119 			}
    120 			continue
    121 		}
    122 		s := b.String()
    123 		if s != tt.raw {
    124 			t.Errorf("%s: got %d-byte %q want %d-byte %q", tt.desc, n, s, len(tt.raw), tt.raw)
    125 		}
    126 	}
    127 }
    128