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-rw-r--r--src/io/io_test.go697
1 files changed, 697 insertions, 0 deletions
diff --git a/src/io/io_test.go b/src/io/io_test.go
new file mode 100644
index 0000000..9491ffa
--- /dev/null
+++ b/src/io/io_test.go
@@ -0,0 +1,697 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package io_test
+
+import (
+ "bytes"
+ "errors"
+ "fmt"
+ . "io"
+ "os"
+ "strings"
+ "sync"
+ "sync/atomic"
+ "testing"
+)
+
+// A version of bytes.Buffer without ReadFrom and WriteTo
+type Buffer struct {
+ bytes.Buffer
+ ReaderFrom // conflicts with and hides bytes.Buffer's ReaderFrom.
+ WriterTo // conflicts with and hides bytes.Buffer's WriterTo.
+}
+
+// Simple tests, primarily to verify the ReadFrom and WriteTo callouts inside Copy, CopyBuffer and CopyN.
+
+func TestCopy(t *testing.T) {
+ rb := new(Buffer)
+ wb := new(Buffer)
+ rb.WriteString("hello, world.")
+ Copy(wb, rb)
+ if wb.String() != "hello, world." {
+ t.Errorf("Copy did not work properly")
+ }
+}
+
+func TestCopyNegative(t *testing.T) {
+ rb := new(Buffer)
+ wb := new(Buffer)
+ rb.WriteString("hello")
+ Copy(wb, &LimitedReader{R: rb, N: -1})
+ if wb.String() != "" {
+ t.Errorf("Copy on LimitedReader with N<0 copied data")
+ }
+
+ CopyN(wb, rb, -1)
+ if wb.String() != "" {
+ t.Errorf("CopyN with N<0 copied data")
+ }
+}
+
+func TestCopyBuffer(t *testing.T) {
+ rb := new(Buffer)
+ wb := new(Buffer)
+ rb.WriteString("hello, world.")
+ CopyBuffer(wb, rb, make([]byte, 1)) // Tiny buffer to keep it honest.
+ if wb.String() != "hello, world." {
+ t.Errorf("CopyBuffer did not work properly")
+ }
+}
+
+func TestCopyBufferNil(t *testing.T) {
+ rb := new(Buffer)
+ wb := new(Buffer)
+ rb.WriteString("hello, world.")
+ CopyBuffer(wb, rb, nil) // Should allocate a buffer.
+ if wb.String() != "hello, world." {
+ t.Errorf("CopyBuffer did not work properly")
+ }
+}
+
+func TestCopyReadFrom(t *testing.T) {
+ rb := new(Buffer)
+ wb := new(bytes.Buffer) // implements ReadFrom.
+ rb.WriteString("hello, world.")
+ Copy(wb, rb)
+ if wb.String() != "hello, world." {
+ t.Errorf("Copy did not work properly")
+ }
+}
+
+func TestCopyWriteTo(t *testing.T) {
+ rb := new(bytes.Buffer) // implements WriteTo.
+ wb := new(Buffer)
+ rb.WriteString("hello, world.")
+ Copy(wb, rb)
+ if wb.String() != "hello, world." {
+ t.Errorf("Copy did not work properly")
+ }
+}
+
+// Version of bytes.Buffer that checks whether WriteTo was called or not
+type writeToChecker struct {
+ bytes.Buffer
+ writeToCalled bool
+}
+
+func (wt *writeToChecker) WriteTo(w Writer) (int64, error) {
+ wt.writeToCalled = true
+ return wt.Buffer.WriteTo(w)
+}
+
+// It's preferable to choose WriterTo over ReaderFrom, since a WriterTo can issue one large write,
+// while the ReaderFrom must read until EOF, potentially allocating when running out of buffer.
+// Make sure that we choose WriterTo when both are implemented.
+func TestCopyPriority(t *testing.T) {
+ rb := new(writeToChecker)
+ wb := new(bytes.Buffer)
+ rb.WriteString("hello, world.")
+ Copy(wb, rb)
+ if wb.String() != "hello, world." {
+ t.Errorf("Copy did not work properly")
+ } else if !rb.writeToCalled {
+ t.Errorf("WriteTo was not prioritized over ReadFrom")
+ }
+}
+
+type zeroErrReader struct {
+ err error
+}
+
+func (r zeroErrReader) Read(p []byte) (int, error) {
+ return copy(p, []byte{0}), r.err
+}
+
+type errWriter struct {
+ err error
+}
+
+func (w errWriter) Write([]byte) (int, error) {
+ return 0, w.err
+}
+
+// In case a Read results in an error with non-zero bytes read, and
+// the subsequent Write also results in an error, the error from Write
+// is returned, as it is the one that prevented progressing further.
+func TestCopyReadErrWriteErr(t *testing.T) {
+ er, ew := errors.New("readError"), errors.New("writeError")
+ r, w := zeroErrReader{err: er}, errWriter{err: ew}
+ n, err := Copy(w, r)
+ if n != 0 || err != ew {
+ t.Errorf("Copy(zeroErrReader, errWriter) = %d, %v; want 0, writeError", n, err)
+ }
+}
+
+func TestCopyN(t *testing.T) {
+ rb := new(Buffer)
+ wb := new(Buffer)
+ rb.WriteString("hello, world.")
+ CopyN(wb, rb, 5)
+ if wb.String() != "hello" {
+ t.Errorf("CopyN did not work properly")
+ }
+}
+
+func TestCopyNReadFrom(t *testing.T) {
+ rb := new(Buffer)
+ wb := new(bytes.Buffer) // implements ReadFrom.
+ rb.WriteString("hello")
+ CopyN(wb, rb, 5)
+ if wb.String() != "hello" {
+ t.Errorf("CopyN did not work properly")
+ }
+}
+
+func TestCopyNWriteTo(t *testing.T) {
+ rb := new(bytes.Buffer) // implements WriteTo.
+ wb := new(Buffer)
+ rb.WriteString("hello, world.")
+ CopyN(wb, rb, 5)
+ if wb.String() != "hello" {
+ t.Errorf("CopyN did not work properly")
+ }
+}
+
+func BenchmarkCopyNSmall(b *testing.B) {
+ bs := bytes.Repeat([]byte{0}, 512+1)
+ rd := bytes.NewReader(bs)
+ buf := new(Buffer)
+ b.ResetTimer()
+
+ for i := 0; i < b.N; i++ {
+ CopyN(buf, rd, 512)
+ rd.Reset(bs)
+ }
+}
+
+func BenchmarkCopyNLarge(b *testing.B) {
+ bs := bytes.Repeat([]byte{0}, (32*1024)+1)
+ rd := bytes.NewReader(bs)
+ buf := new(Buffer)
+ b.ResetTimer()
+
+ for i := 0; i < b.N; i++ {
+ CopyN(buf, rd, 32*1024)
+ rd.Reset(bs)
+ }
+}
+
+type noReadFrom struct {
+ w Writer
+}
+
+func (w *noReadFrom) Write(p []byte) (n int, err error) {
+ return w.w.Write(p)
+}
+
+type wantedAndErrReader struct{}
+
+func (wantedAndErrReader) Read(p []byte) (int, error) {
+ return len(p), errors.New("wantedAndErrReader error")
+}
+
+func TestCopyNEOF(t *testing.T) {
+ // Test that EOF behavior is the same regardless of whether
+ // argument to CopyN has ReadFrom.
+
+ b := new(bytes.Buffer)
+
+ n, err := CopyN(&noReadFrom{b}, strings.NewReader("foo"), 3)
+ if n != 3 || err != nil {
+ t.Errorf("CopyN(noReadFrom, foo, 3) = %d, %v; want 3, nil", n, err)
+ }
+
+ n, err = CopyN(&noReadFrom{b}, strings.NewReader("foo"), 4)
+ if n != 3 || err != EOF {
+ t.Errorf("CopyN(noReadFrom, foo, 4) = %d, %v; want 3, EOF", n, err)
+ }
+
+ n, err = CopyN(b, strings.NewReader("foo"), 3) // b has read from
+ if n != 3 || err != nil {
+ t.Errorf("CopyN(bytes.Buffer, foo, 3) = %d, %v; want 3, nil", n, err)
+ }
+
+ n, err = CopyN(b, strings.NewReader("foo"), 4) // b has read from
+ if n != 3 || err != EOF {
+ t.Errorf("CopyN(bytes.Buffer, foo, 4) = %d, %v; want 3, EOF", n, err)
+ }
+
+ n, err = CopyN(b, wantedAndErrReader{}, 5)
+ if n != 5 || err != nil {
+ t.Errorf("CopyN(bytes.Buffer, wantedAndErrReader, 5) = %d, %v; want 5, nil", n, err)
+ }
+
+ n, err = CopyN(&noReadFrom{b}, wantedAndErrReader{}, 5)
+ if n != 5 || err != nil {
+ t.Errorf("CopyN(noReadFrom, wantedAndErrReader, 5) = %d, %v; want 5, nil", n, err)
+ }
+}
+
+func TestReadAtLeast(t *testing.T) {
+ var rb bytes.Buffer
+ testReadAtLeast(t, &rb)
+}
+
+// A version of bytes.Buffer that returns n > 0, err on Read
+// when the input is exhausted.
+type dataAndErrorBuffer struct {
+ err error
+ bytes.Buffer
+}
+
+func (r *dataAndErrorBuffer) Read(p []byte) (n int, err error) {
+ n, err = r.Buffer.Read(p)
+ if n > 0 && r.Buffer.Len() == 0 && err == nil {
+ err = r.err
+ }
+ return
+}
+
+func TestReadAtLeastWithDataAndEOF(t *testing.T) {
+ var rb dataAndErrorBuffer
+ rb.err = EOF
+ testReadAtLeast(t, &rb)
+}
+
+func TestReadAtLeastWithDataAndError(t *testing.T) {
+ var rb dataAndErrorBuffer
+ rb.err = fmt.Errorf("fake error")
+ testReadAtLeast(t, &rb)
+}
+
+func testReadAtLeast(t *testing.T, rb ReadWriter) {
+ rb.Write([]byte("0123"))
+ buf := make([]byte, 2)
+ n, err := ReadAtLeast(rb, buf, 2)
+ if err != nil {
+ t.Error(err)
+ }
+ if n != 2 {
+ t.Errorf("expected to have read 2 bytes, got %v", n)
+ }
+ n, err = ReadAtLeast(rb, buf, 4)
+ if err != ErrShortBuffer {
+ t.Errorf("expected ErrShortBuffer got %v", err)
+ }
+ if n != 0 {
+ t.Errorf("expected to have read 0 bytes, got %v", n)
+ }
+ n, err = ReadAtLeast(rb, buf, 1)
+ if err != nil {
+ t.Error(err)
+ }
+ if n != 2 {
+ t.Errorf("expected to have read 2 bytes, got %v", n)
+ }
+ n, err = ReadAtLeast(rb, buf, 2)
+ if err != EOF {
+ t.Errorf("expected EOF, got %v", err)
+ }
+ if n != 0 {
+ t.Errorf("expected to have read 0 bytes, got %v", n)
+ }
+ rb.Write([]byte("4"))
+ n, err = ReadAtLeast(rb, buf, 2)
+ want := ErrUnexpectedEOF
+ if rb, ok := rb.(*dataAndErrorBuffer); ok && rb.err != EOF {
+ want = rb.err
+ }
+ if err != want {
+ t.Errorf("expected %v, got %v", want, err)
+ }
+ if n != 1 {
+ t.Errorf("expected to have read 1 bytes, got %v", n)
+ }
+}
+
+func TestTeeReader(t *testing.T) {
+ src := []byte("hello, world")
+ dst := make([]byte, len(src))
+ rb := bytes.NewBuffer(src)
+ wb := new(bytes.Buffer)
+ r := TeeReader(rb, wb)
+ if n, err := ReadFull(r, dst); err != nil || n != len(src) {
+ t.Fatalf("ReadFull(r, dst) = %d, %v; want %d, nil", n, err, len(src))
+ }
+ if !bytes.Equal(dst, src) {
+ t.Errorf("bytes read = %q want %q", dst, src)
+ }
+ if !bytes.Equal(wb.Bytes(), src) {
+ t.Errorf("bytes written = %q want %q", wb.Bytes(), src)
+ }
+ if n, err := r.Read(dst); n != 0 || err != EOF {
+ t.Errorf("r.Read at EOF = %d, %v want 0, EOF", n, err)
+ }
+ rb = bytes.NewBuffer(src)
+ pr, pw := Pipe()
+ pr.Close()
+ r = TeeReader(rb, pw)
+ if n, err := ReadFull(r, dst); n != 0 || err != ErrClosedPipe {
+ t.Errorf("closed tee: ReadFull(r, dst) = %d, %v; want 0, EPIPE", n, err)
+ }
+}
+
+func TestSectionReader_ReadAt(t *testing.T) {
+ dat := "a long sample data, 1234567890"
+ tests := []struct {
+ data string
+ off int
+ n int
+ bufLen int
+ at int
+ exp string
+ err error
+ }{
+ {data: "", off: 0, n: 10, bufLen: 2, at: 0, exp: "", err: EOF},
+ {data: dat, off: 0, n: len(dat), bufLen: 0, at: 0, exp: "", err: nil},
+ {data: dat, off: len(dat), n: 1, bufLen: 1, at: 0, exp: "", err: EOF},
+ {data: dat, off: 0, n: len(dat) + 2, bufLen: len(dat), at: 0, exp: dat, err: nil},
+ {data: dat, off: 0, n: len(dat), bufLen: len(dat) / 2, at: 0, exp: dat[:len(dat)/2], err: nil},
+ {data: dat, off: 0, n: len(dat), bufLen: len(dat), at: 0, exp: dat, err: nil},
+ {data: dat, off: 0, n: len(dat), bufLen: len(dat) / 2, at: 2, exp: dat[2 : 2+len(dat)/2], err: nil},
+ {data: dat, off: 3, n: len(dat), bufLen: len(dat) / 2, at: 2, exp: dat[5 : 5+len(dat)/2], err: nil},
+ {data: dat, off: 3, n: len(dat) / 2, bufLen: len(dat)/2 - 2, at: 2, exp: dat[5 : 5+len(dat)/2-2], err: nil},
+ {data: dat, off: 3, n: len(dat) / 2, bufLen: len(dat)/2 + 2, at: 2, exp: dat[5 : 5+len(dat)/2-2], err: EOF},
+ {data: dat, off: 0, n: 0, bufLen: 0, at: -1, exp: "", err: EOF},
+ {data: dat, off: 0, n: 0, bufLen: 0, at: 1, exp: "", err: EOF},
+ }
+ for i, tt := range tests {
+ r := strings.NewReader(tt.data)
+ s := NewSectionReader(r, int64(tt.off), int64(tt.n))
+ buf := make([]byte, tt.bufLen)
+ if n, err := s.ReadAt(buf, int64(tt.at)); n != len(tt.exp) || string(buf[:n]) != tt.exp || err != tt.err {
+ t.Fatalf("%d: ReadAt(%d) = %q, %v; expected %q, %v", i, tt.at, buf[:n], err, tt.exp, tt.err)
+ }
+ if _r, off, n := s.Outer(); _r != r || off != int64(tt.off) || n != int64(tt.n) {
+ t.Fatalf("%d: Outer() = %v, %d, %d; expected %v, %d, %d", i, _r, off, n, r, tt.off, tt.n)
+ }
+ }
+}
+
+func TestSectionReader_Seek(t *testing.T) {
+ // Verifies that NewSectionReader's Seeker behaves like bytes.NewReader (which is like strings.NewReader)
+ br := bytes.NewReader([]byte("foo"))
+ sr := NewSectionReader(br, 0, int64(len("foo")))
+
+ for _, whence := range []int{SeekStart, SeekCurrent, SeekEnd} {
+ for offset := int64(-3); offset <= 4; offset++ {
+ brOff, brErr := br.Seek(offset, whence)
+ srOff, srErr := sr.Seek(offset, whence)
+ if (brErr != nil) != (srErr != nil) || brOff != srOff {
+ t.Errorf("For whence %d, offset %d: bytes.Reader.Seek = (%v, %v) != SectionReader.Seek = (%v, %v)",
+ whence, offset, brOff, brErr, srErr, srOff)
+ }
+ }
+ }
+
+ // And verify we can just seek past the end and get an EOF
+ got, err := sr.Seek(100, SeekStart)
+ if err != nil || got != 100 {
+ t.Errorf("Seek = %v, %v; want 100, nil", got, err)
+ }
+
+ n, err := sr.Read(make([]byte, 10))
+ if n != 0 || err != EOF {
+ t.Errorf("Read = %v, %v; want 0, EOF", n, err)
+ }
+}
+
+func TestSectionReader_Size(t *testing.T) {
+ tests := []struct {
+ data string
+ want int64
+ }{
+ {"a long sample data, 1234567890", 30},
+ {"", 0},
+ }
+
+ for _, tt := range tests {
+ r := strings.NewReader(tt.data)
+ sr := NewSectionReader(r, 0, int64(len(tt.data)))
+ if got := sr.Size(); got != tt.want {
+ t.Errorf("Size = %v; want %v", got, tt.want)
+ }
+ }
+}
+
+func TestSectionReader_Max(t *testing.T) {
+ r := strings.NewReader("abcdef")
+ const maxint64 = 1<<63 - 1
+ sr := NewSectionReader(r, 3, maxint64)
+ n, err := sr.Read(make([]byte, 3))
+ if n != 3 || err != nil {
+ t.Errorf("Read = %v %v, want 3, nil", n, err)
+ }
+ n, err = sr.Read(make([]byte, 3))
+ if n != 0 || err != EOF {
+ t.Errorf("Read = %v, %v, want 0, EOF", n, err)
+ }
+ if _r, off, n := sr.Outer(); _r != r || off != 3 || n != maxint64 {
+ t.Fatalf("Outer = %v, %d, %d; expected %v, %d, %d", _r, off, n, r, 3, int64(maxint64))
+ }
+}
+
+// largeWriter returns an invalid count that is larger than the number
+// of bytes provided (issue 39978).
+type largeWriter struct {
+ err error
+}
+
+func (w largeWriter) Write(p []byte) (int, error) {
+ return len(p) + 1, w.err
+}
+
+func TestCopyLargeWriter(t *testing.T) {
+ want := ErrInvalidWrite
+ rb := new(Buffer)
+ wb := largeWriter{}
+ rb.WriteString("hello, world.")
+ if _, err := Copy(wb, rb); err != want {
+ t.Errorf("Copy error: got %v, want %v", err, want)
+ }
+
+ want = errors.New("largeWriterError")
+ rb = new(Buffer)
+ wb = largeWriter{err: want}
+ rb.WriteString("hello, world.")
+ if _, err := Copy(wb, rb); err != want {
+ t.Errorf("Copy error: got %v, want %v", err, want)
+ }
+}
+
+func TestNopCloserWriterToForwarding(t *testing.T) {
+ for _, tc := range [...]struct {
+ Name string
+ r Reader
+ }{
+ {"not a WriterTo", Reader(nil)},
+ {"a WriterTo", struct {
+ Reader
+ WriterTo
+ }{}},
+ } {
+ nc := NopCloser(tc.r)
+
+ _, expected := tc.r.(WriterTo)
+ _, got := nc.(WriterTo)
+ if expected != got {
+ t.Errorf("NopCloser incorrectly forwards WriterTo for %s, got %t want %t", tc.Name, got, expected)
+ }
+ }
+}
+
+func TestOffsetWriter_Seek(t *testing.T) {
+ tmpfilename := "TestOffsetWriter_Seek"
+ tmpfile, err := os.CreateTemp(t.TempDir(), tmpfilename)
+ if err != nil || tmpfile == nil {
+ t.Fatalf("CreateTemp(%s) failed: %v", tmpfilename, err)
+ }
+ defer tmpfile.Close()
+ w := NewOffsetWriter(tmpfile, 0)
+
+ // Should throw error errWhence if whence is not valid
+ t.Run("errWhence", func(t *testing.T) {
+ for _, whence := range []int{-3, -2, -1, 3, 4, 5} {
+ var offset int64 = 0
+ gotOff, gotErr := w.Seek(offset, whence)
+ if gotOff != 0 || gotErr != ErrWhence {
+ t.Errorf("For whence %d, offset %d, OffsetWriter.Seek got: (%d, %v), want: (%d, %v)",
+ whence, offset, gotOff, gotErr, 0, ErrWhence)
+ }
+ }
+ })
+
+ // Should throw error errOffset if offset is negative
+ t.Run("errOffset", func(t *testing.T) {
+ for _, whence := range []int{SeekStart, SeekCurrent} {
+ for offset := int64(-3); offset < 0; offset++ {
+ gotOff, gotErr := w.Seek(offset, whence)
+ if gotOff != 0 || gotErr != ErrOffset {
+ t.Errorf("For whence %d, offset %d, OffsetWriter.Seek got: (%d, %v), want: (%d, %v)",
+ whence, offset, gotOff, gotErr, 0, ErrOffset)
+ }
+ }
+ }
+ })
+
+ // Normal tests
+ t.Run("normal", func(t *testing.T) {
+ tests := []struct {
+ offset int64
+ whence int
+ returnOff int64
+ }{
+ // keep in order
+ {whence: SeekStart, offset: 1, returnOff: 1},
+ {whence: SeekStart, offset: 2, returnOff: 2},
+ {whence: SeekStart, offset: 3, returnOff: 3},
+ {whence: SeekCurrent, offset: 1, returnOff: 4},
+ {whence: SeekCurrent, offset: 2, returnOff: 6},
+ {whence: SeekCurrent, offset: 3, returnOff: 9},
+ }
+ for idx, tt := range tests {
+ gotOff, gotErr := w.Seek(tt.offset, tt.whence)
+ if gotOff != tt.returnOff || gotErr != nil {
+ t.Errorf("%d:: For whence %d, offset %d, OffsetWriter.Seek got: (%d, %v), want: (%d, <nil>)",
+ idx+1, tt.whence, tt.offset, gotOff, gotErr, tt.returnOff)
+ }
+ }
+ })
+}
+
+func TestOffsetWriter_WriteAt(t *testing.T) {
+ const content = "0123456789ABCDEF"
+ contentSize := int64(len(content))
+ tmpdir, err := os.MkdirTemp(t.TempDir(), "TestOffsetWriter_WriteAt")
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ work := func(off, at int64) {
+ position := fmt.Sprintf("off_%d_at_%d", off, at)
+ tmpfile, err := os.CreateTemp(tmpdir, position)
+ if err != nil || tmpfile == nil {
+ t.Fatalf("CreateTemp(%s) failed: %v", position, err)
+ }
+ defer tmpfile.Close()
+
+ var writeN int64
+ var wg sync.WaitGroup
+ // Concurrent writes, one byte at a time
+ for step, value := range []byte(content) {
+ wg.Add(1)
+ go func(wg *sync.WaitGroup, tmpfile *os.File, value byte, off, at int64, step int) {
+ defer wg.Done()
+
+ w := NewOffsetWriter(tmpfile, off)
+ n, e := w.WriteAt([]byte{value}, at+int64(step))
+ if e != nil {
+ t.Errorf("WriteAt failed. off: %d, at: %d, step: %d\n error: %v", off, at, step, e)
+ }
+ atomic.AddInt64(&writeN, int64(n))
+ }(&wg, tmpfile, value, off, at, step)
+ }
+ wg.Wait()
+
+ // Read one more byte to reach EOF
+ buf := make([]byte, contentSize+1)
+ readN, err := tmpfile.ReadAt(buf, off+at)
+ if err != EOF {
+ t.Fatalf("ReadAt failed: %v", err)
+ }
+ readContent := string(buf[:contentSize])
+ if writeN != int64(readN) || writeN != contentSize || readContent != content {
+ t.Fatalf("%s:: WriteAt(%s, %d) error. \ngot n: %v, content: %s \nexpected n: %v, content: %v",
+ position, content, at, readN, readContent, contentSize, content)
+ }
+ }
+ for off := int64(0); off < 2; off++ {
+ for at := int64(0); at < 2; at++ {
+ work(off, at)
+ }
+ }
+}
+
+func TestWriteAt_PositionPriorToBase(t *testing.T) {
+ tmpdir := t.TempDir()
+ tmpfilename := "TestOffsetWriter_WriteAt"
+ tmpfile, err := os.CreateTemp(tmpdir, tmpfilename)
+ if err != nil {
+ t.Fatalf("CreateTemp(%s) failed: %v", tmpfilename, err)
+ }
+ defer tmpfile.Close()
+
+ // start writing position in OffsetWriter
+ offset := int64(10)
+ // position we want to write to the tmpfile
+ at := int64(-1)
+ w := NewOffsetWriter(tmpfile, offset)
+ _, e := w.WriteAt([]byte("hello"), at)
+ if e == nil {
+ t.Errorf("error expected to be not nil")
+ }
+}
+
+func TestOffsetWriter_Write(t *testing.T) {
+ const content = "0123456789ABCDEF"
+ contentSize := len(content)
+ tmpdir := t.TempDir()
+
+ makeOffsetWriter := func(name string) (*OffsetWriter, *os.File) {
+ tmpfilename := "TestOffsetWriter_Write_" + name
+ tmpfile, err := os.CreateTemp(tmpdir, tmpfilename)
+ if err != nil || tmpfile == nil {
+ t.Fatalf("CreateTemp(%s) failed: %v", tmpfilename, err)
+ }
+ return NewOffsetWriter(tmpfile, 0), tmpfile
+ }
+ checkContent := func(name string, f *os.File) {
+ // Read one more byte to reach EOF
+ buf := make([]byte, contentSize+1)
+ readN, err := f.ReadAt(buf, 0)
+ if err != EOF {
+ t.Fatalf("ReadAt failed, err: %v", err)
+ }
+ readContent := string(buf[:contentSize])
+ if readN != contentSize || readContent != content {
+ t.Fatalf("%s error. \ngot n: %v, content: %s \nexpected n: %v, content: %v",
+ name, readN, readContent, contentSize, content)
+ }
+ }
+
+ var name string
+ name = "Write"
+ t.Run(name, func(t *testing.T) {
+ // Write directly (off: 0, at: 0)
+ // Write content to file
+ w, f := makeOffsetWriter(name)
+ defer f.Close()
+ for _, value := range []byte(content) {
+ n, err := w.Write([]byte{value})
+ if err != nil {
+ t.Fatalf("Write failed, n: %d, err: %v", n, err)
+ }
+ }
+ checkContent(name, f)
+
+ // Copy -> Write
+ // Copy file f to file f2
+ name = "Copy"
+ w2, f2 := makeOffsetWriter(name)
+ defer f2.Close()
+ Copy(w2, f)
+ checkContent(name, f2)
+ })
+
+ // Copy -> WriteTo -> Write
+ // Note: strings.Reader implements the io.WriterTo interface.
+ name = "Write_Of_Copy_WriteTo"
+ t.Run(name, func(t *testing.T) {
+ w, f := makeOffsetWriter(name)
+ defer f.Close()
+ Copy(w, strings.NewReader(content))
+ checkContent(name, f)
+ })
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-04 15:01:30 +0000