Brent Austin | ba3052e | 2015-04-21 16:08:23 -0700 | [diff] [blame] | 1 | // Copyright 2012 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 bytes_test |
| 6 | |
| 7 | import ( |
| 8 | . "bytes" |
| 9 | "fmt" |
| 10 | "io" |
| 11 | "io/ioutil" |
Brent Austin | ba3052e | 2015-04-21 16:08:23 -0700 | [diff] [blame] | 12 | "sync" |
| 13 | "testing" |
| 14 | ) |
| 15 | |
| 16 | func TestReader(t *testing.T) { |
| 17 | r := NewReader([]byte("0123456789")) |
| 18 | tests := []struct { |
| 19 | off int64 |
| 20 | seek int |
| 21 | n int |
| 22 | want string |
| 23 | wantpos int64 |
Dan Willemsen | 38f2dba | 2016-07-08 14:54:35 -0700 | [diff] [blame] | 24 | readerr error |
Brent Austin | ba3052e | 2015-04-21 16:08:23 -0700 | [diff] [blame] | 25 | seekerr string |
| 26 | }{ |
Dan Willemsen | 38f2dba | 2016-07-08 14:54:35 -0700 | [diff] [blame] | 27 | {seek: io.SeekStart, off: 0, n: 20, want: "0123456789"}, |
| 28 | {seek: io.SeekStart, off: 1, n: 1, want: "1"}, |
| 29 | {seek: io.SeekCurrent, off: 1, wantpos: 3, n: 2, want: "34"}, |
| 30 | {seek: io.SeekStart, off: -1, seekerr: "bytes.Reader.Seek: negative position"}, |
| 31 | {seek: io.SeekStart, off: 1 << 33, wantpos: 1 << 33, readerr: io.EOF}, |
| 32 | {seek: io.SeekCurrent, off: 1, wantpos: 1<<33 + 1, readerr: io.EOF}, |
| 33 | {seek: io.SeekStart, n: 5, want: "01234"}, |
| 34 | {seek: io.SeekCurrent, n: 5, want: "56789"}, |
| 35 | {seek: io.SeekEnd, off: -1, n: 1, wantpos: 9, want: "9"}, |
Brent Austin | ba3052e | 2015-04-21 16:08:23 -0700 | [diff] [blame] | 36 | } |
| 37 | |
| 38 | for i, tt := range tests { |
| 39 | pos, err := r.Seek(tt.off, tt.seek) |
| 40 | if err == nil && tt.seekerr != "" { |
| 41 | t.Errorf("%d. want seek error %q", i, tt.seekerr) |
| 42 | continue |
| 43 | } |
| 44 | if err != nil && err.Error() != tt.seekerr { |
| 45 | t.Errorf("%d. seek error = %q; want %q", i, err.Error(), tt.seekerr) |
| 46 | continue |
| 47 | } |
| 48 | if tt.wantpos != 0 && tt.wantpos != pos { |
| 49 | t.Errorf("%d. pos = %d, want %d", i, pos, tt.wantpos) |
| 50 | } |
| 51 | buf := make([]byte, tt.n) |
| 52 | n, err := r.Read(buf) |
Dan Willemsen | 38f2dba | 2016-07-08 14:54:35 -0700 | [diff] [blame] | 53 | if err != tt.readerr { |
| 54 | t.Errorf("%d. read = %v; want %v", i, err, tt.readerr) |
Brent Austin | ba3052e | 2015-04-21 16:08:23 -0700 | [diff] [blame] | 55 | continue |
| 56 | } |
| 57 | got := string(buf[:n]) |
| 58 | if got != tt.want { |
| 59 | t.Errorf("%d. got %q; want %q", i, got, tt.want) |
| 60 | } |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | func TestReadAfterBigSeek(t *testing.T) { |
| 65 | r := NewReader([]byte("0123456789")) |
Dan Willemsen | 38f2dba | 2016-07-08 14:54:35 -0700 | [diff] [blame] | 66 | if _, err := r.Seek(1<<31+5, io.SeekStart); err != nil { |
Brent Austin | ba3052e | 2015-04-21 16:08:23 -0700 | [diff] [blame] | 67 | t.Fatal(err) |
| 68 | } |
| 69 | if n, err := r.Read(make([]byte, 10)); n != 0 || err != io.EOF { |
| 70 | t.Errorf("Read = %d, %v; want 0, EOF", n, err) |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | func TestReaderAt(t *testing.T) { |
| 75 | r := NewReader([]byte("0123456789")) |
| 76 | tests := []struct { |
| 77 | off int64 |
| 78 | n int |
| 79 | want string |
| 80 | wanterr interface{} |
| 81 | }{ |
| 82 | {0, 10, "0123456789", nil}, |
| 83 | {1, 10, "123456789", io.EOF}, |
| 84 | {1, 9, "123456789", nil}, |
| 85 | {11, 10, "", io.EOF}, |
| 86 | {0, 0, "", nil}, |
| 87 | {-1, 0, "", "bytes.Reader.ReadAt: negative offset"}, |
| 88 | } |
| 89 | for i, tt := range tests { |
| 90 | b := make([]byte, tt.n) |
| 91 | rn, err := r.ReadAt(b, tt.off) |
| 92 | got := string(b[:rn]) |
| 93 | if got != tt.want { |
| 94 | t.Errorf("%d. got %q; want %q", i, got, tt.want) |
| 95 | } |
| 96 | if fmt.Sprintf("%v", err) != fmt.Sprintf("%v", tt.wanterr) { |
| 97 | t.Errorf("%d. got error = %v; want %v", i, err, tt.wanterr) |
| 98 | } |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | func TestReaderAtConcurrent(t *testing.T) { |
| 103 | // Test for the race detector, to verify ReadAt doesn't mutate |
| 104 | // any state. |
| 105 | r := NewReader([]byte("0123456789")) |
| 106 | var wg sync.WaitGroup |
| 107 | for i := 0; i < 5; i++ { |
| 108 | wg.Add(1) |
| 109 | go func(i int) { |
| 110 | defer wg.Done() |
| 111 | var buf [1]byte |
| 112 | r.ReadAt(buf[:], int64(i)) |
| 113 | }(i) |
| 114 | } |
| 115 | wg.Wait() |
| 116 | } |
| 117 | |
| 118 | func TestEmptyReaderConcurrent(t *testing.T) { |
| 119 | // Test for the race detector, to verify a Read that doesn't yield any bytes |
| 120 | // is okay to use from multiple goroutines. This was our historic behavior. |
| 121 | // See golang.org/issue/7856 |
| 122 | r := NewReader([]byte{}) |
| 123 | var wg sync.WaitGroup |
| 124 | for i := 0; i < 5; i++ { |
| 125 | wg.Add(2) |
| 126 | go func() { |
| 127 | defer wg.Done() |
| 128 | var buf [1]byte |
| 129 | r.Read(buf[:]) |
| 130 | }() |
| 131 | go func() { |
| 132 | defer wg.Done() |
| 133 | r.Read(nil) |
| 134 | }() |
| 135 | } |
| 136 | wg.Wait() |
| 137 | } |
| 138 | |
| 139 | func TestReaderWriteTo(t *testing.T) { |
| 140 | for i := 0; i < 30; i += 3 { |
| 141 | var l int |
| 142 | if i > 0 { |
| 143 | l = len(data) / i |
| 144 | } |
| 145 | s := data[:l] |
| 146 | r := NewReader(testBytes[:l]) |
| 147 | var b Buffer |
| 148 | n, err := r.WriteTo(&b) |
| 149 | if expect := int64(len(s)); n != expect { |
| 150 | t.Errorf("got %v; want %v", n, expect) |
| 151 | } |
| 152 | if err != nil { |
| 153 | t.Errorf("for length %d: got error = %v; want nil", l, err) |
| 154 | } |
| 155 | if b.String() != s { |
| 156 | t.Errorf("got string %q; want %q", b.String(), s) |
| 157 | } |
| 158 | if r.Len() != 0 { |
| 159 | t.Errorf("reader contains %v bytes; want 0", r.Len()) |
| 160 | } |
| 161 | } |
| 162 | } |
| 163 | |
| 164 | func TestReaderLen(t *testing.T) { |
| 165 | const data = "hello world" |
| 166 | r := NewReader([]byte(data)) |
| 167 | if got, want := r.Len(), 11; got != want { |
| 168 | t.Errorf("r.Len(): got %d, want %d", got, want) |
| 169 | } |
| 170 | if n, err := r.Read(make([]byte, 10)); err != nil || n != 10 { |
| 171 | t.Errorf("Read failed: read %d %v", n, err) |
| 172 | } |
| 173 | if got, want := r.Len(), 1; got != want { |
| 174 | t.Errorf("r.Len(): got %d, want %d", got, want) |
| 175 | } |
| 176 | if n, err := r.Read(make([]byte, 1)); err != nil || n != 1 { |
Dan Willemsen | 38f2dba | 2016-07-08 14:54:35 -0700 | [diff] [blame] | 177 | t.Errorf("Read failed: read %d %v; want 1, nil", n, err) |
Brent Austin | ba3052e | 2015-04-21 16:08:23 -0700 | [diff] [blame] | 178 | } |
| 179 | if got, want := r.Len(), 0; got != want { |
| 180 | t.Errorf("r.Len(): got %d, want %d", got, want) |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | var UnreadRuneErrorTests = []struct { |
| 185 | name string |
| 186 | f func(*Reader) |
| 187 | }{ |
| 188 | {"Read", func(r *Reader) { r.Read([]byte{0}) }}, |
| 189 | {"ReadByte", func(r *Reader) { r.ReadByte() }}, |
| 190 | {"UnreadRune", func(r *Reader) { r.UnreadRune() }}, |
Dan Willemsen | 38f2dba | 2016-07-08 14:54:35 -0700 | [diff] [blame] | 191 | {"Seek", func(r *Reader) { r.Seek(0, io.SeekCurrent) }}, |
Brent Austin | ba3052e | 2015-04-21 16:08:23 -0700 | [diff] [blame] | 192 | {"WriteTo", func(r *Reader) { r.WriteTo(&Buffer{}) }}, |
| 193 | } |
| 194 | |
| 195 | func TestUnreadRuneError(t *testing.T) { |
| 196 | for _, tt := range UnreadRuneErrorTests { |
| 197 | reader := NewReader([]byte("0123456789")) |
| 198 | if _, _, err := reader.ReadRune(); err != nil { |
| 199 | // should not happen |
| 200 | t.Fatal(err) |
| 201 | } |
| 202 | tt.f(reader) |
| 203 | err := reader.UnreadRune() |
| 204 | if err == nil { |
| 205 | t.Errorf("Unreading after %s: expected error", tt.name) |
| 206 | } |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | func TestReaderDoubleUnreadRune(t *testing.T) { |
| 211 | buf := NewBuffer([]byte("groucho")) |
| 212 | if _, _, err := buf.ReadRune(); err != nil { |
| 213 | // should not happen |
| 214 | t.Fatal(err) |
| 215 | } |
| 216 | if err := buf.UnreadByte(); err != nil { |
| 217 | // should not happen |
| 218 | t.Fatal(err) |
| 219 | } |
| 220 | if err := buf.UnreadByte(); err == nil { |
| 221 | t.Fatal("UnreadByte: expected error, got nil") |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | // verify that copying from an empty reader always has the same results, |
| 226 | // regardless of the presence of a WriteTo method. |
| 227 | func TestReaderCopyNothing(t *testing.T) { |
| 228 | type nErr struct { |
| 229 | n int64 |
| 230 | err error |
| 231 | } |
| 232 | type justReader struct { |
| 233 | io.Reader |
| 234 | } |
| 235 | type justWriter struct { |
| 236 | io.Writer |
| 237 | } |
| 238 | discard := justWriter{ioutil.Discard} // hide ReadFrom |
| 239 | |
| 240 | var with, withOut nErr |
| 241 | with.n, with.err = io.Copy(discard, NewReader(nil)) |
| 242 | withOut.n, withOut.err = io.Copy(discard, justReader{NewReader(nil)}) |
| 243 | if with != withOut { |
| 244 | t.Errorf("behavior differs: with = %#v; without: %#v", with, withOut) |
| 245 | } |
| 246 | } |
Dan Willemsen | 09eb3b1 | 2015-09-16 14:34:17 -0700 | [diff] [blame] | 247 | |
| 248 | // tests that Len is affected by reads, but Size is not. |
| 249 | func TestReaderLenSize(t *testing.T) { |
| 250 | r := NewReader([]byte("abc")) |
| 251 | io.CopyN(ioutil.Discard, r, 1) |
| 252 | if r.Len() != 2 { |
| 253 | t.Errorf("Len = %d; want 2", r.Len()) |
| 254 | } |
| 255 | if r.Size() != 3 { |
| 256 | t.Errorf("Size = %d; want 3", r.Size()) |
| 257 | } |
| 258 | } |
Dan Willemsen | 38f2dba | 2016-07-08 14:54:35 -0700 | [diff] [blame] | 259 | |
| 260 | func TestReaderReset(t *testing.T) { |
| 261 | r := NewReader([]byte("世界")) |
| 262 | if _, _, err := r.ReadRune(); err != nil { |
| 263 | t.Errorf("ReadRune: unexpected error: %v", err) |
| 264 | } |
| 265 | |
| 266 | const want = "abcdef" |
| 267 | r.Reset([]byte(want)) |
| 268 | if err := r.UnreadRune(); err == nil { |
| 269 | t.Errorf("UnreadRune: expected error, got nil") |
| 270 | } |
| 271 | buf, err := ioutil.ReadAll(r) |
| 272 | if err != nil { |
| 273 | t.Errorf("ReadAll: unexpected error: %v", err) |
| 274 | } |
| 275 | if got := string(buf); got != want { |
| 276 | t.Errorf("ReadAll: got %q, want %q", got, want) |
| 277 | } |
| 278 | } |