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Source file src/encoding/hex/hex_test.go

Documentation: encoding/hex

     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 hex
     6  
     7  import (
     8  	"bytes"
     9  	"fmt"
    10  	"io"
    11  	"strings"
    12  	"testing"
    13  )
    14  
    15  type encDecTest struct {
    16  	enc string
    17  	dec []byte
    18  }
    19  
    20  var encDecTests = []encDecTest{
    21  	{"", []byte{}},
    22  	{"0001020304050607", []byte{0, 1, 2, 3, 4, 5, 6, 7}},
    23  	{"08090a0b0c0d0e0f", []byte{8, 9, 10, 11, 12, 13, 14, 15}},
    24  	{"f0f1f2f3f4f5f6f7", []byte{0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7}},
    25  	{"f8f9fafbfcfdfeff", []byte{0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff}},
    26  	{"67", []byte{'g'}},
    27  	{"e3a1", []byte{0xe3, 0xa1}},
    28  }
    29  
    30  func TestEncode(t *testing.T) {
    31  	for i, test := range encDecTests {
    32  		dst := make([]byte, EncodedLen(len(test.dec)))
    33  		n := Encode(dst, test.dec)
    34  		if n != len(dst) {
    35  			t.Errorf("#%d: bad return value: got: %d want: %d", i, n, len(dst))
    36  		}
    37  		if string(dst) != test.enc {
    38  			t.Errorf("#%d: got: %#v want: %#v", i, dst, test.enc)
    39  		}
    40  	}
    41  }
    42  
    43  func TestDecode(t *testing.T) {
    44  	// Case for decoding uppercase hex characters, since
    45  	// Encode always uses lowercase.
    46  	decTests := append(encDecTests, encDecTest{"F8F9FAFBFCFDFEFF", []byte{0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff}})
    47  	for i, test := range decTests {
    48  		dst := make([]byte, DecodedLen(len(test.enc)))
    49  		n, err := Decode(dst, []byte(test.enc))
    50  		if err != nil {
    51  			t.Errorf("#%d: bad return value: got:%d want:%d", i, n, len(dst))
    52  		} else if !bytes.Equal(dst, test.dec) {
    53  			t.Errorf("#%d: got: %#v want: %#v", i, dst, test.dec)
    54  		}
    55  	}
    56  }
    57  
    58  func TestEncodeToString(t *testing.T) {
    59  	for i, test := range encDecTests {
    60  		s := EncodeToString(test.dec)
    61  		if s != test.enc {
    62  			t.Errorf("#%d got:%s want:%s", i, s, test.enc)
    63  		}
    64  	}
    65  }
    66  
    67  func TestDecodeString(t *testing.T) {
    68  	for i, test := range encDecTests {
    69  		dst, err := DecodeString(test.enc)
    70  		if err != nil {
    71  			t.Errorf("#%d: unexpected err value: %s", i, err)
    72  			continue
    73  		}
    74  		if !bytes.Equal(dst, test.dec) {
    75  			t.Errorf("#%d: got: %#v want: #%v", i, dst, test.dec)
    76  		}
    77  	}
    78  }
    79  
    80  var errTests = []struct {
    81  	in  string
    82  	out string
    83  	err error
    84  }{
    85  	{"", "", nil},
    86  	{"0", "", ErrLength},
    87  	{"zd4aa", "", InvalidByteError('z')},
    88  	{"d4aaz", "\xd4\xaa", InvalidByteError('z')},
    89  	{"30313", "01", ErrLength},
    90  	{"0g", "", InvalidByteError('g')},
    91  	{"00gg", "\x00", InvalidByteError('g')},
    92  	{"0\x01", "", InvalidByteError('\x01')},
    93  	{"ffeed", "\xff\xee", ErrLength},
    94  }
    95  
    96  func TestDecodeErr(t *testing.T) {
    97  	for _, tt := range errTests {
    98  		out := make([]byte, len(tt.in)+10)
    99  		n, err := Decode(out, []byte(tt.in))
   100  		if string(out[:n]) != tt.out || err != tt.err {
   101  			t.Errorf("Decode(%q) = %q, %v, want %q, %v", tt.in, string(out[:n]), err, tt.out, tt.err)
   102  		}
   103  	}
   104  }
   105  
   106  func TestDecodeStringErr(t *testing.T) {
   107  	for _, tt := range errTests {
   108  		out, err := DecodeString(tt.in)
   109  		if string(out) != tt.out || err != tt.err {
   110  			t.Errorf("DecodeString(%q) = %q, %v, want %q, %v", tt.in, out, err, tt.out, tt.err)
   111  		}
   112  	}
   113  }
   114  
   115  func TestEncoderDecoder(t *testing.T) {
   116  	for _, multiplier := range []int{1, 128, 192} {
   117  		for _, test := range encDecTests {
   118  			input := bytes.Repeat(test.dec, multiplier)
   119  			output := strings.Repeat(test.enc, multiplier)
   120  
   121  			var buf bytes.Buffer
   122  			enc := NewEncoder(&buf)
   123  			r := struct{ io.Reader }{bytes.NewReader(input)} // io.Reader only; not io.WriterTo
   124  			if n, err := io.CopyBuffer(enc, r, make([]byte, 7)); n != int64(len(input)) || err != nil {
   125  				t.Errorf("encoder.Write(%q*%d) = (%d, %v), want (%d, nil)", test.dec, multiplier, n, err, len(input))
   126  				continue
   127  			}
   128  
   129  			if encDst := buf.String(); encDst != output {
   130  				t.Errorf("buf(%q*%d) = %v, want %v", test.dec, multiplier, encDst, output)
   131  				continue
   132  			}
   133  
   134  			dec := NewDecoder(&buf)
   135  			var decBuf bytes.Buffer
   136  			w := struct{ io.Writer }{&decBuf} // io.Writer only; not io.ReaderFrom
   137  			if _, err := io.CopyBuffer(w, dec, make([]byte, 7)); err != nil || decBuf.Len() != len(input) {
   138  				t.Errorf("decoder.Read(%q*%d) = (%d, %v), want (%d, nil)", test.enc, multiplier, decBuf.Len(), err, len(input))
   139  			}
   140  
   141  			if !bytes.Equal(decBuf.Bytes(), input) {
   142  				t.Errorf("decBuf(%q*%d) = %v, want %v", test.dec, multiplier, decBuf.Bytes(), input)
   143  				continue
   144  			}
   145  		}
   146  	}
   147  }
   148  
   149  func TestDecoderErr(t *testing.T) {
   150  	for _, tt := range errTests {
   151  		dec := NewDecoder(strings.NewReader(tt.in))
   152  		out, err := io.ReadAll(dec)
   153  		wantErr := tt.err
   154  		// Decoder is reading from stream, so it reports io.ErrUnexpectedEOF instead of ErrLength.
   155  		if wantErr == ErrLength {
   156  			wantErr = io.ErrUnexpectedEOF
   157  		}
   158  		if string(out) != tt.out || err != wantErr {
   159  			t.Errorf("NewDecoder(%q) = %q, %v, want %q, %v", tt.in, out, err, tt.out, wantErr)
   160  		}
   161  	}
   162  }
   163  
   164  func TestDumper(t *testing.T) {
   165  	var in [40]byte
   166  	for i := range in {
   167  		in[i] = byte(i + 30)
   168  	}
   169  
   170  	for stride := 1; stride < len(in); stride++ {
   171  		var out bytes.Buffer
   172  		dumper := Dumper(&out)
   173  		done := 0
   174  		for done < len(in) {
   175  			todo := done + stride
   176  			if todo > len(in) {
   177  				todo = len(in)
   178  			}
   179  			dumper.Write(in[done:todo])
   180  			done = todo
   181  		}
   182  
   183  		dumper.Close()
   184  		if !bytes.Equal(out.Bytes(), expectedHexDump) {
   185  			t.Errorf("stride: %d failed. got:\n%s\nwant:\n%s", stride, out.Bytes(), expectedHexDump)
   186  		}
   187  	}
   188  }
   189  
   190  func TestDumper_doubleclose(t *testing.T) {
   191  	var out bytes.Buffer
   192  	dumper := Dumper(&out)
   193  
   194  	dumper.Write([]byte(`gopher`))
   195  	dumper.Close()
   196  	dumper.Close()
   197  	dumper.Write([]byte(`gopher`))
   198  	dumper.Close()
   199  
   200  	expected := "00000000  67 6f 70 68 65 72                                 |gopher|\n"
   201  	if out.String() != expected {
   202  		t.Fatalf("got:\n%#v\nwant:\n%#v", out.String(), expected)
   203  	}
   204  }
   205  
   206  func TestDumper_earlyclose(t *testing.T) {
   207  	var out bytes.Buffer
   208  	dumper := Dumper(&out)
   209  
   210  	dumper.Close()
   211  	dumper.Write([]byte(`gopher`))
   212  
   213  	expected := ""
   214  	if out.String() != expected {
   215  		t.Fatalf("got:\n%#v\nwant:\n%#v", out.String(), expected)
   216  	}
   217  }
   218  
   219  func TestDump(t *testing.T) {
   220  	var in [40]byte
   221  	for i := range in {
   222  		in[i] = byte(i + 30)
   223  	}
   224  
   225  	out := []byte(Dump(in[:]))
   226  	if !bytes.Equal(out, expectedHexDump) {
   227  		t.Errorf("got:\n%s\nwant:\n%s", out, expectedHexDump)
   228  	}
   229  }
   230  
   231  var expectedHexDump = []byte(`00000000  1e 1f 20 21 22 23 24 25  26 27 28 29 2a 2b 2c 2d  |.. !"#$%&'()*+,-|
   232  00000010  2e 2f 30 31 32 33 34 35  36 37 38 39 3a 3b 3c 3d  |./0123456789:;<=|
   233  00000020  3e 3f 40 41 42 43 44 45                           |>?@ABCDE|
   234  `)
   235  
   236  var sink []byte
   237  
   238  func BenchmarkEncode(b *testing.B) {
   239  	for _, size := range []int{256, 1024, 4096, 16384} {
   240  		src := bytes.Repeat([]byte{2, 3, 5, 7, 9, 11, 13, 17}, size/8)
   241  		sink = make([]byte, 2*size)
   242  
   243  		b.Run(fmt.Sprintf("%v", size), func(b *testing.B) {
   244  			b.SetBytes(int64(size))
   245  			for i := 0; i < b.N; i++ {
   246  				Encode(sink, src)
   247  			}
   248  		})
   249  	}
   250  }
   251  
   252  func BenchmarkDecode(b *testing.B) {
   253  	for _, size := range []int{256, 1024, 4096, 16384} {
   254  		src := bytes.Repeat([]byte{'2', 'b', '7', '4', '4', 'f', 'a', 'a'}, size/8)
   255  		sink = make([]byte, size/2)
   256  
   257  		b.Run(fmt.Sprintf("%v", size), func(b *testing.B) {
   258  			b.SetBytes(int64(size))
   259  			for i := 0; i < b.N; i++ {
   260  				Decode(sink, src)
   261  			}
   262  		})
   263  	}
   264  }
   265  
   266  func BenchmarkDump(b *testing.B) {
   267  	for _, size := range []int{256, 1024, 4096, 16384} {
   268  		src := bytes.Repeat([]byte{2, 3, 5, 7, 9, 11, 13, 17}, size/8)
   269  
   270  		b.Run(fmt.Sprintf("%v", size), func(b *testing.B) {
   271  			b.SetBytes(int64(size))
   272  			for i := 0; i < b.N; i++ {
   273  				Dump(src)
   274  			}
   275  		})
   276  	}
   277  }
   278  

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