summaryrefslogtreecommitdiffstats
path: root/src/io/io_test.go
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:14:23 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:14:23 +0000
commit73df946d56c74384511a194dd01dbe099584fd1a (patch)
treefd0bcea490dd81327ddfbb31e215439672c9a068 /src/io/io_test.go
parentInitial commit. (diff)
downloadgolang-1.16-upstream.tar.xz
golang-1.16-upstream.zip
Adding upstream version 1.16.10.upstream/1.16.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/io/io_test.go')
-rw-r--r--src/io/io_test.go459
1 files changed, 459 insertions, 0 deletions
diff --git a/src/io/io_test.go b/src/io/io_test.go
new file mode 100644
index 0000000..5b355e8
--- /dev/null
+++ b/src/io/io_test.go
@@ -0,0 +1,459 @@
+// 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"
+ "strings"
+ "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)
+ }
+ }
+}
+
+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)
+ }
+ }
+}
+
+// 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)
+ }
+}