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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:15:26 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:15:26 +0000 |
commit | 82539ad8d59729fb45b0bb0edda8f2bddb719eb1 (patch) | |
tree | 58f0b58e6f44f0e04d4a6373132cf426fa835fa7 /src/io/io_test.go | |
parent | Initial commit. (diff) | |
download | golang-1.17-82539ad8d59729fb45b0bb0edda8f2bddb719eb1.tar.xz golang-1.17-82539ad8d59729fb45b0bb0edda8f2bddb719eb1.zip |
Adding upstream version 1.17.13.upstream/1.17.13upstream
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.go | 459 |
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) + } +} |