Repository: jszwec/s3fs
Branch: main
Commit: 7b413ce12de4
Files: 12
Total size: 54.9 KB

Directory structure:
gitextract_kmeqcja3/

├── .github/
│   └── workflows/
│       └── go.yml
├── .gitignore
├── LICENSE
├── README.md
├── dir.go
├── file.go
├── fs.go
├── fs_test.go
├── go.mod
├── go.sum
└── test/
    ├── localstack/
    │   └── docker-compose.yml
    └── minio/
        └── docker-compose.yml

================================================
FILE CONTENTS
================================================

================================================
FILE: .github/workflows/go.yml
================================================
name: Go

on:
  push:
    branches: [ main, v1, v2 ]
  pull_request:
    branches: [ main, v1, v2 ]

jobs:
  localstack:
    runs-on: ubuntu-latest
    services:
      minio:
        image: localstack/localstack:0.14.0
        ports:
          - "4566:4566"
          - "4571:4571"
        env:
          SERVICES: s3

    steps:
    - uses: actions/checkout@v2

    - name: Set up Go
      uses: actions/setup-go@v2
      with:
        go-version: 1.21
    
    - name: Wait for localstack 
      run: 'for i in {1..20}; do sleep 3 && curl --silent --fail http://localhost:4566/health | grep "\"s3\": \"available\"" > /dev/null && break; done'

    - name: Test
      run: go test -v -endpoint='http://localhost:4566' -cover

  minio:
    runs-on: ubuntu-latest
    
    steps:
    - uses: actions/checkout@v2

    - name: Set up Go
      uses: actions/setup-go@v2
      with:
        go-version: 1.21
    
    - name: Test
      env:
          SERVER_ENDPOINT: http://localhost:9000
          ACCESS_KEY: minioadmin
          SECRET_KEY: minioadmin
          MINIO_ACCESS_KEY: minioadmin
          MINIO_SECRET_KEY: minioadmin
          S3FS_TEST_AWS_ACCESS_KEY_ID: minioadmin
          S3FS_TEST_AWS_SECRET_ACCESS_KEY: minioadmin
      run: |
          wget -O /tmp/minio -q https://dl.minio.io/server/minio/release/linux-amd64/minio
          chmod +x /tmp/minio
          /tmp/minio server /tmp/data &
          go test -v -endpoint='http://localhost:9000' -cover


================================================
FILE: .gitignore
================================================
# Binaries for programs and plugins
*.exe
*.exe~
*.dll
*.so
*.dylib

# Test binary, built with `go test -c`
*.test

# Output of the go coverage tool, specifically when used with LiteIDE
*.out

# Dependency directories (remove the comment below to include it)
# vendor/


================================================
FILE: LICENSE
================================================
MIT License

Copyright (c) 2021 Jacek Szwec

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.


================================================
FILE: README.md
================================================
# s3fs [![Go Reference](https://pkg.go.dev/badge/github.com/jszwec/s3fs.svg)](https://pkg.go.dev/github.com/jszwec/s3fs) ![Go](https://github.com/jszwec/s3fs/workflows/Go/badge.svg?branch=main)

Package s3fs provides a S3 implementation for Go1.16 [filesystem](https://tip.golang.org/pkg/io/fs/#FS) interface.

Since S3 is a flat structure, s3fs simulates directories by using
prefixes and "/" delim. ModTime on directories is always zero value.

# SDK Versions
```github.com/jszwec/s3fs``` uses aws sdk v1

```github.com/jszwec/s3fs/v2``` uses aws sdk v2


# Example (SDK v1)
```go
const bucket = "my-bucket"

s, err := session.NewSession()
if err != nil {
    log.Fatal(err)
}

s3fs := s3fs.New(s3.New(s), bucket)

// print out all files in s3 bucket.
_ = fs.WalkDir(s3fs, ".", func(path string, d fs.DirEntry, err error) error {
    if err != nil {
        return err
    }

    if d.IsDir() {
        fmt.Println("dir:", path)
        return nil
    }
    fmt.Println("file:", path)
    return nil
})
```

# Installation

```
go get github.com/jszwec/s3fs
```

# Requirements

* Go1.16+


================================================
FILE: dir.go
================================================
package s3fs

import (
	"context"
	"errors"
	"io"
	"io/fs"
	"path"
	"sort"
	"strings"
	"time"

	"github.com/aws/aws-sdk-go-v2/service/s3"
)

var _ fs.ReadDirFile = (*dir)(nil)

type dir struct {
	fileInfo
	s3cl   Client
	bucket string
	marker *string
	done   bool
	buf    []fs.DirEntry
	dirs   map[dirEntry]bool
}

func (d *dir) Stat() (fs.FileInfo, error) {
	return &d.fileInfo, nil
}

func (d *dir) Read([]byte) (int, error) {
	return 0, &fs.PathError{
		Op:   "read",
		Path: d.name,
		Err:  errors.New("is a directory"),
	}
}

func (d *dir) Close() error {
	return nil
}

func (d *dir) ReadDir(n int) (des []fs.DirEntry, err error) {
	if n <= 0 {
		switch err := d.readAll(); {
		case err == nil:
		case errors.Is(err, io.EOF):
			return []fs.DirEntry{}, nil
		default:
			return nil, err
		}

		des, d.buf = d.buf, nil
		return des, nil
	}

loop:
	for len(d.buf) < n {
		switch err := d.readNext(); {
		case err == nil:
			continue
		case errors.Is(err, io.EOF):
			break loop
		default:
			return nil, err
		}
	}

	offset := min(n, len(d.buf))
	des, d.buf = d.buf[:offset:offset], d.buf[offset:]

	if d.done && len(d.buf) == 0 {
		err = io.EOF
	}

	return des, err
}

func (d *dir) readAll() error {
	for !d.done {
		switch err := d.readNext(); {
		case err == nil:
			continue
		case errors.Is(err, io.EOF):
			return nil
		default:
			return err
		}
	}
	return io.EOF
}

func (d *dir) readNext() error {
	if d.done {
		return io.EOF
	}

	name := strings.TrimRight(d.name, "/")
	switch {
	case name == ".":
		name = ""
	default:
		name += "/"
	}

	out, err := d.s3cl.ListObjects(
		context.Background(),
		&s3.ListObjectsInput{
			Bucket:    &d.bucket,
			Delimiter: ptr("/"),
			Prefix:    &name,
			Marker:    d.marker,
		})
	if err != nil {
		return err
	}

	if d.name != "." && len(out.CommonPrefixes)+len(out.Contents) == 0 {
		return &fs.PathError{
			Op:   "readdir",
			Path: strings.TrimSuffix(name, "/"),
			Err:  fs.ErrNotExist,
		}
	}

	d.marker = out.NextMarker
	d.done = out.IsTruncated != nil && !(*out.IsTruncated)

	if d.dirs == nil {
		d.dirs = make(map[dirEntry]bool)
	}

	for _, p := range out.CommonPrefixes {
		if p.Prefix == nil {
			continue
		}

		de := dirEntry{
			fileInfo: fileInfo{
				name: path.Base(*p.Prefix),
				mode: fs.ModeDir,
			},
		}

		if _, ok := d.dirs[de]; !ok {
			d.dirs[de] = false
		}
	}

	for _, o := range out.Contents {
		if o.Key == nil {
			continue
		}

		d.buf = append(d.buf, dirEntry{
			fileInfo: fileInfo{
				name:    path.Base(*o.Key),
				size:    derefInt64(o.Size),
				modTime: derefTime(o.LastModified),
			},
		})
	}

	d.mergeDirFiles()

	if d.done {
		return io.EOF
	}
	return nil
}

func (d *dir) mergeDirFiles() {
	if d.buf == nil {
		// according to fs docs ReadDir should never return nil slice,
		// so we set it here.
		d.buf = []fs.DirEntry{}
	}

	// we need a current len for sort.Search that doesn't change; otherwise
	// we could not append to the same slice.
	l := len(d.buf)
	for de, used := range d.dirs {
		if used {
			continue
		}

		i := sort.Search(l, func(i int) bool {
			return d.buf[i].Name() >= de.Name()
		})

		if i == l && !d.done {
			continue
		}
		d.buf = append(d.buf, de)
		d.dirs[de] = true
	}

	sort.Slice(d.buf, func(i, j int) bool {
		return d.buf[i].Name() < d.buf[j].Name()
	})
}

type dirEntry struct {
	fileInfo
}

func (de dirEntry) Type() fs.FileMode          { return de.Mode().Type() }
func (de dirEntry) Info() (fs.FileInfo, error) { return de.fileInfo, nil }

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func derefInt64(n *int64) int64 {
	if n != nil {
		return *n
	}
	return 0
}

func derefTime(t *time.Time) time.Time {
	if t != nil {
		return *t
	}
	return time.Time{}
}


================================================
FILE: file.go
================================================
package s3fs

import (
	"context"
	"errors"
	"fmt"
	"io"
	"io/fs"
	"net/http"
	"path"
	"time"

	awshttp "github.com/aws/aws-sdk-go-v2/aws/transport/http"
	"github.com/aws/aws-sdk-go-v2/service/s3"
)

var (
	_ fs.File     = (*file)(nil)
	_ fs.FileInfo = (*fileInfo)(nil)
	_ io.Seeker   = (*file)(nil)
)

type file struct {
	cl     Client
	bucket string
	name   string

	io.ReadCloser
	stat   func() (fs.FileInfo, error)
	offset int64
	eTag   string
}

func openFile(cl Client, bucket string, name string) (fs.File, error) {
	out, err := cl.GetObject(context.Background(), &s3.GetObjectInput{
		Key:    &name,
		Bucket: &bucket,
	})

	if err != nil {
		return nil, err
	}

	statFunc := getStatFunc(cl, bucket, name, *out)

	return &file{
		cl:         cl,
		bucket:     bucket,
		name:       name,
		ReadCloser: out.Body,
		stat:       statFunc,
		offset:     0,
		eTag:       *out.ETag,
	}, nil
}

func getStatFunc(cl Client, bucket string, name string, s3ObjOutput s3.GetObjectOutput) func() (fs.FileInfo, error) {
	statFunc := func() (fs.FileInfo, error) {
		return stat(cl, bucket, name)
	}

	if s3ObjOutput.ContentLength != nil && s3ObjOutput.LastModified != nil {
		// if we got all the information from GetObjectOutput
		// then we can cache fileinfo instead of making
		// another call in case Stat is called.
		statFunc = func() (fs.FileInfo, error) {
			return &fileInfo{
				name:    path.Base(name),
				size:    *s3ObjOutput.ContentLength,
				modTime: *s3ObjOutput.LastModified,
			}, nil
		}
	}

	return statFunc
}

func (f *file) Read(p []byte) (int, error) {
	n, err := f.ReadCloser.Read(p)
	f.offset += int64(n)
	return n, err
}

func (f *file) Seek(offset int64, whence int) (int64, error) {
	newOffset := f.offset

	stat, err := f.Stat()
	if err != nil {
		return 0, err
	}
	size := stat.Size()

	switch whence {
	case io.SeekStart:
		newOffset = offset
	case io.SeekCurrent:
		newOffset += offset
	case io.SeekEnd:
		newOffset = size + offset
	default:
		return 0, errors.New("s3fs.file.Seek: invalid whence")
	}

	// If the position has not moved, there is no need to make a new query
	if f.offset == newOffset {
		return newOffset, nil
	}

	if newOffset < 0 {
		return 0, errors.New("s3fs.file.Seek: seeked to a negative position")
	}

	if f.eTag == "" {
		return 0, errors.New("s3fs.file.Seek: cannot seek. remote file has no etag")
	}

	if err := f.Close(); err != nil {
		return f.offset, err
	}

	if newOffset >= size {
		f.ReadCloser = io.NopCloser(eofReader{})
		f.offset = newOffset
		return f.offset, nil
	}

	rawObject, err := f.cl.GetObject(
		context.Background(),
		&s3.GetObjectInput{
			Bucket:  &f.bucket,
			Key:     &f.name,
			Range:   ptr(fmt.Sprintf("bytes=%d-", newOffset)),
			IfMatch: &f.eTag,
		})

	if err != nil {
		if e := new(awshttp.ResponseError); errors.As(err, &e) {
			if e.HTTPStatusCode() == http.StatusPreconditionFailed {
				return 0, fmt.Errorf("s3fs.file.Seek: file has changed while seeking: %w", fs.ErrNotExist)
			}
		}
		return 0, err
	}

	f.offset = newOffset
	f.ReadCloser = rawObject.Body

	return f.offset, nil
}

func (f file) Stat() (fs.FileInfo, error) { return f.stat() }

type fileInfo struct {
	name    string
	size    int64
	mode    fs.FileMode
	modTime time.Time
}

func (fi fileInfo) Name() string       { return path.Base(fi.name) }
func (fi fileInfo) Size() int64        { return fi.size }
func (fi fileInfo) Mode() fs.FileMode  { return fi.mode }
func (fi fileInfo) ModTime() time.Time { return fi.modTime }
func (fi fileInfo) IsDir() bool        { return fi.mode.IsDir() }
func (fi fileInfo) Sys() interface{}   { return nil }

type eofReader struct{}

func (eofReader) Read([]byte) (int, error) { return 0, io.EOF }

func ptr[T any](v T) *T {
	return &v
}


================================================
FILE: fs.go
================================================
// Package s3fs provides a S3 implementation for Go1.16 filesystem interface.
package s3fs

import (
	"context"
	"errors"
	"io/fs"

	"github.com/aws/aws-sdk-go-v2/aws/transport/http"
	"github.com/aws/aws-sdk-go-v2/service/s3"
	"github.com/aws/aws-sdk-go-v2/service/s3/types"
)

var (
	_ fs.FS        = (*S3FS)(nil)
	_ fs.StatFS    = (*S3FS)(nil)
	_ fs.ReadDirFS = (*S3FS)(nil)
)

var errNotDir = errors.New("not a dir")

// Option is a function that provides optional features to S3FS.
type Option func(*S3FS)

// WithReadSeeker enables Seek functionality on files opened with this fs.
//
// BUG(WilliamFrei): Seeking on S3 requires reopening the file at the specified
// position. This can cause problems if the file changed between opening
// and calling Seek. In that case, fs.ErrNotExist error is returned, which
// has to be handled by the caller.
func WithReadSeeker(fsys *S3FS) { fsys.readSeeker = true }

// Client wraps the s3 client methods that this package is using.
// This interface may change in the future and should not be relied on by
// packages using it.
type Client interface {
	HeadObject(ctx context.Context, params *s3.HeadObjectInput, optFns ...func(*s3.Options)) (*s3.HeadObjectOutput, error)
	ListObjects(ctx context.Context, params *s3.ListObjectsInput, optFns ...func(*s3.Options)) (*s3.ListObjectsOutput, error)
	GetObject(ctx context.Context, params *s3.GetObjectInput, optFns ...func(*s3.Options)) (*s3.GetObjectOutput, error)
}

// S3FS is a S3 filesystem implementation.
//
// S3 has a flat structure instead of a hierarchy. S3FS simulates directories
// by using prefixes and delims ("/"). Because directories are simulated, ModTime
// is always a default Time value (IsZero returns true).
type S3FS struct {
	cl         Client
	bucket     string
	readSeeker bool
}

// New returns a new filesystem that works on the specified bucket.
func New(cl Client, bucket string, opts ...Option) *S3FS {
	fsys := &S3FS{
		cl:     cl,
		bucket: bucket,
	}

	for _, opt := range opts {
		opt(fsys)
	}

	return fsys
}

// Open implements fs.FS.
func (f *S3FS) Open(name string) (fs.File, error) {
	if !fs.ValidPath(name) {
		return nil, &fs.PathError{
			Op:   "open",
			Path: name,
			Err:  fs.ErrInvalid,
		}
	}

	if name == "." {
		return openDir(f.cl, f.bucket, name)
	}

	file, err := openFile(f.cl, f.bucket, name)

	if err != nil {
		if isNotFoundErr(err) {
			switch d, err := openDir(f.cl, f.bucket, name); {
			case err == nil:
				return d, nil
			case !isNotFoundErr(err) && !errors.Is(err, errNotDir) && !errors.Is(err, fs.ErrNotExist):
				return nil, err
			}

			return nil, &fs.PathError{
				Op:   "open",
				Path: name,
				Err:  fs.ErrNotExist,
			}
		}

		return nil, &fs.PathError{
			Op:   "open",
			Path: name,
			Err:  err,
		}
	}

	if !f.readSeeker {
		file = fileNoSeek{file}
	}

	return file, nil
}

// Stat implements fs.StatFS.
func (f *S3FS) Stat(name string) (fs.FileInfo, error) {
	fi, err := stat(f.cl, f.bucket, name)
	if err != nil {
		return nil, &fs.PathError{
			Op:   "stat",
			Path: name,
			Err:  err,
		}
	}
	return fi, nil
}

// ReadDir implements fs.ReadDirFS.
func (f *S3FS) ReadDir(name string) ([]fs.DirEntry, error) {
	d, err := openDir(f.cl, f.bucket, name)
	if err != nil {
		return nil, &fs.PathError{
			Op:   "readdir",
			Path: name,
			Err:  err,
		}
	}
	return d.ReadDir(-1)
}

func stat(s3cl Client, bucket, name string) (fs.FileInfo, error) {
	if !fs.ValidPath(name) {
		return nil, fs.ErrInvalid
	}

	if name == "." {
		return &dir{
			s3cl:   s3cl,
			bucket: bucket,
			fileInfo: fileInfo{
				name: ".",
				mode: fs.ModeDir,
			},
		}, nil
	}

	head, err := s3cl.HeadObject(
		context.Background(),
		&s3.HeadObjectInput{
			Bucket: &bucket,
			Key:    &name,
		})
	if err != nil {
		if !isNotFoundErr(err) {
			return nil, err
		}
	} else {
		return &fileInfo{
			name:    name,
			size:    derefInt64(head.ContentLength),
			mode:    0,
			modTime: derefTime(head.LastModified),
		}, nil
	}

	out, err := s3cl.ListObjects(
		context.Background(),
		&s3.ListObjectsInput{
			Bucket:    &bucket,
			Delimiter: ptr("/"),
			Prefix:    ptr(name + "/"),
			MaxKeys:   ptr[int32](1),
		})
	if err != nil {
		return nil, err
	}
	if len(out.CommonPrefixes) > 0 || len(out.Contents) > 0 {
		return &dir{
			s3cl:   s3cl,
			bucket: bucket,
			fileInfo: fileInfo{
				name: name,
				mode: fs.ModeDir,
			},
		}, nil
	}
	return nil, fs.ErrNotExist
}

func openDir(s3cl Client, bucket, name string) (fs.ReadDirFile, error) {
	fi, err := stat(s3cl, bucket, name)
	if err != nil {
		return nil, err
	}

	if d, ok := fi.(fs.ReadDirFile); ok {
		return d, nil
	}
	return nil, errNotDir
}

func isNotFoundErr(err error) bool {
	if e := new(types.NoSuchKey); errors.As(err, &e) {
		return true
	}

	if e := new(http.ResponseError); errors.As(err, &e) {
		// localstack workaround
		if e.HTTPStatusCode() == 404 {
			return true
		}
	}

	return false
}

type fileNoSeek struct{ fs.File }


================================================
FILE: fs_test.go
================================================
package s3fs_test

import (
	"bytes"
	"context"
	"crypto/tls"
	"errors"
	"flag"
	"io"
	"io/fs"
	"net/http"
	"os"
	"reflect"
	"strings"
	"sync/atomic"
	"testing"
	"testing/fstest"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/feature/s3/manager"
	"github.com/aws/aws-sdk-go-v2/service/s3"
	"github.com/aws/aws-sdk-go-v2/service/s3/types"
	"github.com/jszwec/s3fs/v2"
)

var (
	endpoint   = flag.String("endpoint", "http://localhost:4566", "s3 endpoint")
	bucket     = flag.String("bucket", "test-github.com-jszwec-s3fs", "bucket name")
	skipVerify = flag.Bool("skip-verify", true, "http insecure skip verify")
)

var (
	accessKeyID = envDefault("S3FS_TEST_AWS_ACCESS_KEY_ID", "1")
	secretKey   = envDefault("S3FS_TEST_AWS_SECRET_ACCESS_KEY", "1")
	region      = envDefault("S3FS_TEST_AWS_REGION", "us-east-1")
)

func TestMain(m *testing.M) {
	flag.Parse()
	os.Exit(m.Run())
}

func TestSeeker(t *testing.T) {
	s3cl, cl := newClient(t)

	const testFile = "file.txt"
	content := []byte("content")

	createBucket(t, s3cl, *bucket)
	cleanBucket(t, s3cl, *bucket)

	writeFile(t, s3cl, *bucket, testFile, content)

	t.Cleanup(func() {
		cleanBucket(t, s3cl, *bucket)

		t.Log("test stats:")
		t.Log("ListObjects calls:", atomic.LoadInt64(&listC))
		t.Log("GetObject calls:", atomic.LoadInt64(&getC))
	})

	t.Run("'s3fs.New' does not implement Seeker", func(t *testing.T) {
		testFs := s3fs.New(cl, *bucket)
		data, err := testFs.Open(testFile)

		if err != nil {
			t.Fatal(err)
		}

		_, ok := data.(io.Seeker)

		if ok {
			t.Fatalf("Expected 'data' to not implement the Seeker interface")
		}
	})

	t.Run("seek throws error if file changed", func(t *testing.T) {
		const otherTestFile = "otherFile.txt"
		originalContent := []byte("con")
		changedContent := []byte("tent")

		writeFile(t, s3cl, *bucket, otherTestFile, originalContent)

		testFs := s3fs.New(s3cl, *bucket, s3fs.WithReadSeeker)
		data, err := testFs.Open(otherTestFile)

		if err != nil {
			t.Fatal(err)
		}

		if _, err := data.(io.Seeker).Seek(0, io.SeekEnd); err != nil {
			t.Fatal(err)
		}

		deleteFile(t, s3cl, *bucket, otherTestFile)
		writeFile(t, s3cl, *bucket, otherTestFile, changedContent)

		_, err = data.(io.Seeker).Seek(0, io.SeekStart)
		if !errors.Is(err, fs.ErrNotExist) {
			t.Fatalf("want=%v; got %v", fs.ErrNotExist, err)
		}
	})

	t.Run("seek once", func(t *testing.T) {
		fixtures := []struct {
			desc     string
			offset   int64
			whence   int
			expected int64
		}{
			{
				desc:     "whence SeekStart ",
				offset:   2,
				whence:   io.SeekStart,
				expected: 2,
			},
			{
				desc:     "whence SeekCurrent",
				offset:   4,
				whence:   io.SeekCurrent,
				expected: 4,
			},
			{
				desc:     "whence SeekEnd",
				offset:   -1,
				whence:   io.SeekEnd,
				expected: int64(len(content)) - 1,
			},
		}

		for _, f := range fixtures {
			f := f
			t.Run(f.desc, func(t *testing.T) {
				testFs := s3fs.New(s3cl, *bucket, s3fs.WithReadSeeker)
				data, err := testFs.Open(testFile)
				if err != nil {
					t.Fatal(err)
				}

				actual, err := data.(io.Seeker).Seek(f.offset, f.whence)
				if err != nil {
					t.Fatal(err)
				}

				if actual != f.expected {
					t.Fatalf("Expected %d, got %d", f.expected, actual)
				}

			})
		}
	})

	t.Run("seek with errors", func(t *testing.T) {
		fixtures := []struct {
			desc         string
			offset       int64
			whence       int
			errorMessage string
		}{
			{
				desc:         "seek before beginning with whence SeekCurrent",
				offset:       -1,
				whence:       io.SeekCurrent,
				errorMessage: "s3fs.file.Seek: seeked to a negative position",
			},
			{
				desc:         "seek before beginning with whence SeekStart",
				offset:       -1,
				whence:       io.SeekStart,
				errorMessage: "s3fs.file.Seek: seeked to a negative position",
			},
			{
				desc:         "seek with invalid whence",
				offset:       0,
				whence:       3,
				errorMessage: "s3fs.file.Seek: invalid whence",
			},
		}

		for _, f := range fixtures {
			f := f
			t.Run(f.desc, func(t *testing.T) {
				testFs := s3fs.New(s3cl, *bucket, s3fs.WithReadSeeker)
				data, err := testFs.Open(testFile)
				if err != nil {
					t.Fatal(err)
				}

				_, err = data.(io.Seeker).Seek(f.offset, f.whence)
				if err == nil {
					t.Fatalf("Expected error after seeking to invalid position, got nil")
				}
				if err.Error() != f.errorMessage {
					t.Fatalf("Expected %s, got %v", f.errorMessage, err)
				}
			})
		}
	})

	t.Run("seek from other starting position", func(t *testing.T) {
		fixtures := []struct {
			desc          string
			initialOffset int
			offset        int64
			whence        int
			expected      int64
		}{
			{
				desc:          "whence SeekStart",
				initialOffset: 3,
				offset:        2,
				whence:        io.SeekStart,
				expected:      2,
			},
			{
				desc:          "whence SeekCurrent",
				initialOffset: 3,
				offset:        3,
				whence:        io.SeekCurrent,
				expected:      6,
			},
			{
				desc:          "whence SeekEnd",
				initialOffset: 3,
				offset:        -1,
				whence:        io.SeekEnd,
				expected:      int64(len(content)) - 1,
			},
		}

		for _, f := range fixtures {
			f := f
			t.Run(f.desc, func(t *testing.T) {
				testFs := s3fs.New(s3cl, *bucket, s3fs.WithReadSeeker)
				data, err := testFs.Open(testFile)
				if err != nil {
					t.Fatal(err)
				}

				readBuffer := make([]byte, f.initialOffset)
				readBytes, err := data.Read(readBuffer)
				if err != nil {
					t.Fatal(err)
				}
				if readBytes != f.initialOffset {
					t.Fatalf("Read failed during test setup")
				}

				actual, err := data.(io.Seeker).Seek(f.offset, f.whence)
				if err != nil {
					t.Fatal(err)
				}

				if actual != f.expected {
					t.Fatalf("Expected %d, got %d", f.expected, actual)
				}
			})
		}
	})

	t.Run("seek then read", func(t *testing.T) {
		fixtures := []struct {
			desc         string
			readBytes    int
			offset       int64
			whence       int
			expected     []byte
			expectingEOF bool
		}{
			{
				desc:         "whence SeekStart",
				readBytes:    3,
				offset:       2,
				whence:       io.SeekStart,
				expected:     content[2:5],
				expectingEOF: false,
			},
			{
				desc:         "whence SeekCurrent",
				readBytes:    1,
				offset:       1,
				whence:       io.SeekCurrent,
				expected:     []byte("o"),
				expectingEOF: false,
			},
			{
				desc:         "seek to end then read 0",
				readBytes:    0,
				offset:       0,
				whence:       io.SeekEnd,
				expected:     []byte(""),
				expectingEOF: true,
			},
			{
				desc:         "whence SeekStart with EOF",
				readBytes:    2,
				offset:       5,
				whence:       io.SeekStart,
				expected:     content[5:7],
				expectingEOF: true,
			},
			{
				desc:         "whence SeekCurrent with EOF",
				readBytes:    3,
				offset:       4,
				whence:       io.SeekCurrent,
				expected:     content[4:7],
				expectingEOF: true,
			},
			{
				desc:         "whence SeekEnd with EOF",
				readBytes:    3,
				offset:       -3,
				whence:       io.SeekEnd,
				expected:     content[len(content)-3:],
				expectingEOF: true,
			},
			{
				desc:         "zero offset and read more than fits the buffer",
				readBytes:    100,
				offset:       0,
				whence:       io.SeekStart,
				expected:     []byte("content"),
				expectingEOF: true,
			},
			{
				desc:         "whence SeekStart offset and read more than fits the buffer",
				readBytes:    100,
				offset:       1,
				whence:       io.SeekStart,
				expected:     []byte("ontent"),
				expectingEOF: true,
			},
			{
				desc:         "whence SeekCurrent offset and read more than fits the buffer",
				readBytes:    100,
				offset:       1,
				whence:       io.SeekCurrent,
				expected:     []byte("ontent"),
				expectingEOF: true,
			},
			{
				desc:         "whence SeekEnd to the end of the file and then read",
				readBytes:    10,
				offset:       0,
				whence:       io.SeekEnd,
				expected:     []byte(""),
				expectingEOF: true,
			},
			{
				desc:         "whence SeekEnd past the end of the file and then read",
				readBytes:    10,
				offset:       1,
				whence:       io.SeekEnd,
				expected:     []byte(""),
				expectingEOF: true,
			},
		}

		for _, f := range fixtures {
			f := f
			t.Run(f.desc, func(t *testing.T) {
				testFs := s3fs.New(s3cl, *bucket, s3fs.WithReadSeeker)
				data, err := testFs.Open(testFile)
				if err != nil {
					t.Fatal(err)
				}

				readSeekers := []struct {
					desc   string
					seeker io.ReadSeeker
				}{
					{desc: "file", seeker: data.(io.ReadSeeker)},
					{desc: "bytes reader", seeker: bytes.NewReader(content)},
				}

				for _, rs := range readSeekers {
					rs := rs
					t.Run(rs.desc, func(t *testing.T) {
						_, err = rs.seeker.Seek(f.offset, f.whence)
						if err != nil {
							t.Fatal(err)
						}

						var buf bytes.Buffer
						_, err := io.CopyN(&buf, rs.seeker, int64(f.readBytes))
						if err != nil && !errors.Is(err, io.EOF) {
							t.Fatal(err)
						}

						if buf.String() != string(f.expected) {
							t.Errorf("expected %s, got %s", f.expected, buf.String())
						}
						if f.expectingEOF {
							newlyReadBytes, err := rs.seeker.Read(make([]byte, 0))
							if newlyReadBytes != 0 {
								t.Fatalf("Read returned unexpected number of bytes: expected 0, got %d", newlyReadBytes)
							}
							if err == nil {
								t.Fatalf("Expected io.EOF error, got nil")
							}
							if !errors.Is(err, io.EOF) {
								t.Fatal(err)
							}
						}
					})
				}
			})
		}
	})

	t.Run("seek twice then read", func(t *testing.T) {
		fixtures := []struct {
			desc         string
			readBytes    int
			firstOffset  int64
			firstWhence  int
			secondOffset int64
			expected     []byte
			expectingEOF bool
		}{
			{
				desc:         "whence SeekStart",
				readBytes:    2,
				firstOffset:  1,
				firstWhence:  io.SeekStart,
				secondOffset: 2,
				expected:     content[3:5],
				expectingEOF: false,
			},
			{
				desc:         "whence SeekCurrent",
				readBytes:    1,
				firstOffset:  2,
				firstWhence:  io.SeekCurrent,
				secondOffset: 3,
				expected:     content[5:6],
				expectingEOF: false,
			},
			{
				desc:         "whence SeekEnd",
				readBytes:    2,
				firstOffset:  -4,
				firstWhence:  io.SeekEnd,
				secondOffset: 1,
				expected:     content[4:6],
				expectingEOF: false,
			},
			{
				desc:         "whence SeekStart with EOF",
				readBytes:    5,
				firstOffset:  1,
				firstWhence:  io.SeekStart,
				secondOffset: 2,
				expected:     content[3:],
				expectingEOF: true,
			},
			{
				desc:         "whence SeekCurrent with EOF",
				readBytes:    2,
				firstOffset:  2,
				firstWhence:  io.SeekCurrent,
				secondOffset: 3,
				expected:     content[5:],
				expectingEOF: true,
			},
			{
				desc:         "whence SeekEnd with EOF",
				readBytes:    7,
				firstOffset:  -5,
				firstWhence:  io.SeekEnd,
				secondOffset: 1,
				expected:     content[3:],
				expectingEOF: true,
			},
		}

		for _, f := range fixtures {
			f := f
			t.Run(f.desc, func(t *testing.T) {
				testFs := s3fs.New(s3cl, *bucket, s3fs.WithReadSeeker)
				data, err := testFs.Open(testFile)
				if err != nil {
					t.Fatal(err)
				}

				readSeekers := []struct {
					desc   string
					seeker io.ReadSeeker
				}{
					{desc: "file", seeker: data.(io.ReadSeeker)},
					{desc: "bytes reader", seeker: bytes.NewReader(content)},
				}

				for _, rs := range readSeekers {
					rs := rs
					t.Run(rs.desc, func(t *testing.T) {
						_, err = rs.seeker.Seek(f.firstOffset, f.firstWhence)
						if err != nil {
							t.Fatal(err)
						}

						_, err = rs.seeker.Seek(f.secondOffset, io.SeekCurrent)
						if err != nil {
							t.Fatal(err)
						}

						var buf bytes.Buffer
						_, err := io.CopyN(&buf, rs.seeker, int64(f.readBytes))
						if err != nil && !errors.Is(err, io.EOF) {
							t.Fatal(err)
						}

						if buf.String() != string(f.expected) {
							t.Errorf("expected %s, got %s", f.expected, buf.String())
						}
						if f.expectingEOF {
							newlyReadBytes, err := rs.seeker.Read(make([]byte, 0))
							if newlyReadBytes != 0 {
								t.Fatalf("Read returned unexpected number of bytes: expected 0, got %d", newlyReadBytes)
							}
							if err == nil {
								t.Fatalf("Expected io.EOF error, got nil")
							}
							if !errors.Is(err, io.EOF) {
								t.Fatal(err)
							}
						}
					})
				}
			})
		}
	})
}

func TestFS(t *testing.T) {
	s3cl, wrappedCl := newClient(t)

	const testFile = "file.txt"

	content := []byte("content")

	allFiles := [...]string{
		testFile,
		"dir/a.txt",
		"dir1/file1.txt",
		"dir1/file2.txt",
		"dir1/dir11/file.txt",
		"dir2/file1.txt",
		"x/file1.txt",
		"y.txt",
		"y2.txt",
		"y3.txt",
		"z/z/file1.txt",
		"a.txt",
		"a/b.txt",
	}

	createBucket(t, s3cl, *bucket)
	cleanBucket(t, s3cl, *bucket)

	t.Run("list empty bucket", func(t *testing.T) {
		fi, err := s3fs.New(wrappedCl, *bucket).Open(".")
		if err != nil {
			t.Errorf("want err to be nil; got %v", err)
		}

		dir := fi.(fs.ReadDirFile)
		fixtures := []struct {
			desc string
			n    int
			err  error
		}{
			{"n > 0", 1, io.EOF},
			{"n <= 0", -1, nil},
		}

		for _, f := range fixtures {
			f := f
			t.Run(f.desc, func(t *testing.T) {
				des, err := dir.ReadDir(f.n)
				if err != f.err {
					t.Errorf("want err to be %v; got %v", f.err, err)
				}

				if des == nil {
					t.Error("want des to not be a nil slice")
				}

				if len(des) > 0 {
					t.Errorf("expected the directory to be empty; got %d elements", len(des))
				}
			})
		}
	})

	for _, f := range allFiles {
		writeFile(t, s3cl, *bucket, f, content)
	}

	t.Cleanup(func() {
		cleanBucket(t, s3cl, *bucket)

		t.Log("test stats:")
		t.Log("ListObjects calls:", atomic.LoadInt64(&listC))
		t.Log("GetObject calls:", atomic.LoadInt64(&getC))
	})

	testFn := func(t *testing.T, s3fs *s3fs.S3FS) {
		t.Run("testing fstest", func(t *testing.T) {
			if testing.Short() {
				t.Skip("short test enabled")
			}

			t.Parallel()
			if err := fstest.TestFS(s3fs, allFiles[:]...); err != nil {
				t.Fatal(err)
			}
		})

		t.Run("readfile", func(t *testing.T) {
			t.Parallel()

			t.Run("success", func(t *testing.T) {
				data, err := fs.ReadFile(s3fs, testFile)
				if err != nil {
					t.Fatal(err)
				}

				if !bytes.Equal(data, []byte("content")) {
					t.Errorf("expect: %s; got %s", data, []byte("content"))
				}
			})

			t.Run("error", func(t *testing.T) {
				t.Run("invalid path", func(t *testing.T) {
					_, err := fs.ReadFile(s3fs, "/")
					if err == nil {
						t.Fatal("expected error")
					}

					var pathErr *fs.PathError
					if !errors.As(err, &pathErr) {
						t.Fatal("expected err to be *PathError")
					}

					expected := fs.PathError{
						Op:   "open",
						Path: "/",
						Err:  fs.ErrInvalid,
					}
					if *pathErr != expected {
						t.Fatalf("want %v; got %v", expected, *pathErr)
					}
				})

				t.Run("directory", func(t *testing.T) {
					_, err := fs.ReadFile(s3fs, ".")
					if err == nil {
						t.Fatal("expected error")
					}

					var perr *fs.PathError
					if !errors.As(err, &perr) {
						t.Fatal("expected err to be *PathError")
					}

					if perr.Op != "read" {
						t.Errorf("want %v; got %v", "read", perr.Op)
					}

					if perr.Path != "." {
						t.Errorf("want %v; got %v", ".", perr.Path)
					}

					if perr.Err.Error() != "is a directory" {
						t.Errorf("want %v; got %v", "is a directory", perr.Err.Error())
					}
				})
			})
		})

		t.Run("stat file", func(t *testing.T) {
			t.Parallel()

			test := func(t *testing.T, fi fs.FileInfo) {
				t.Helper()

				if fi.IsDir() {
					t.Error("expected false")
				}

				if fi.Mode() != 0 {
					t.Errorf("want %d; got %d", 0, fi.Mode())
				}

				if fi.Sys() != nil {
					t.Error("expected Sys to be nil")
				}
			}

			t.Run("file stat", func(t *testing.T) {
				f, err := s3fs.Open(testFile)
				if err != nil {
					t.Fatal("expected err to be nil")
				}
				defer f.Close()

				fi, err := f.Stat()
				if err != nil {
					t.Fatal("expected err to be nil")
				}

				test(t, fi)
			})

			t.Run("fs stat", func(t *testing.T) {
				fi, err := s3fs.Stat(testFile)
				if err != nil {
					t.Fatal("expected err to be nil")
				}

				test(t, fi)
			})

			t.Run("invalid path", func(t *testing.T) {
				_, err := s3fs.Stat("/")
				var pathErr *fs.PathError
				if !errors.As(err, &pathErr) {
					t.Fatal("expected err to be *PathError")
				}

				expected := fs.PathError{
					Op:   "stat",
					Path: "/",
					Err:  fs.ErrInvalid,
				}
				if *pathErr != expected {
					t.Fatalf("want %v; got %v", expected, *pathErr)
				}
			})

			t.Run("does not exist", func(t *testing.T) {
				_, err := s3fs.Stat("not-existing")
				var pathErr *fs.PathError
				if !errors.As(err, &pathErr) {
					t.Fatal("expected err to be *PathError")
				}

				expected := fs.PathError{
					Op:   "stat",
					Path: "not-existing",
					Err:  fs.ErrNotExist,
				}
				if *pathErr != expected {
					t.Fatalf("want %v; got %v", expected, *pathErr)
				}
			})
		})

		t.Run("stat dir", func(t *testing.T) {
			t.Parallel()

			test := func(t *testing.T, fi fs.FileInfo) {
				t.Helper()

				if !fi.IsDir() {
					t.Error("expected true")
				}

				if fi.Mode() != fs.ModeDir {
					t.Errorf("want %d; got %d", fs.ModeDir, fi.Mode())
				}

				if fi.Sys() != nil {
					t.Error("expected Sys to be nil")
				}
			}

			t.Run("top level", func(t *testing.T) {
				fi, err := s3fs.Stat(".")
				if err != nil {
					t.Fatal("expected err to be nil")
				}
				test(t, fi)

				if fi.Name() != "." {
					t.Errorf("want name=%q; got %q", ".", fi.Name())
				}
			})

			t.Run("open z", func(t *testing.T) {
				fi, err := s3fs.Stat("z")
				if err != nil {
					t.Fatal("expected err to be nil")
				}
				test(t, fi)
			})
		})

		t.Run("readdir", func(t *testing.T) {
			t.Parallel()

			t.Run("success", func(t *testing.T) {
				fixtures := []struct {
					desc  string
					path  string
					names []string
					modes []fs.FileMode
					isDir []bool
					size  []int
				}{
					{
						desc:  "top level",
						path:  ".",
						names: []string{"a", "a.txt", "dir", "dir1", "dir2", testFile, "x", "y.txt", "y2.txt", "y3.txt", "z"},
						modes: []fs.FileMode{fs.ModeDir, 0, fs.ModeDir, fs.ModeDir, fs.ModeDir, 0, fs.ModeDir, 0, 0, 0, fs.ModeDir},
						isDir: []bool{true, false, true, true, true, false, true, false, false, false, true},
						size:  []int{0, len(content), 0, 0, 0, len(content), 0, len(content), len(content), len(content), 0},
					},
					{
						desc:  "dir1",
						path:  "dir1",
						names: []string{"dir11", "file1.txt", "file2.txt"},
						modes: []fs.FileMode{fs.ModeDir, 0, 0},
						isDir: []bool{true, false, false},
						size:  []int{0, len(content), len(content)},
					},
					{
						desc:  "dir11",
						path:  "dir1/dir11",
						names: []string{"file.txt"},
						modes: []fs.FileMode{0},
						isDir: []bool{false},
						size:  []int{len(content)},
					},
				}

				for _, f := range fixtures {
					f := f
					test := func(t *testing.T, des []fs.DirEntry) {
						var (
							names []string
							modes []fs.FileMode
							isDir []bool
							size  []int
						)
						for _, de := range des {
							fi, err := de.Info()
							if err != nil {
								t.Fatal("expected nil; got ", err)
							}
							names = append(names, de.Name())
							modes = append(modes, fi.Mode())
							isDir = append(isDir, fi.IsDir())
							size = append(size, int(fi.Size()))
						}

						for _, v := range []struct {
							desc      string
							want, got interface{}
						}{
							{"names", f.names, names},
							{"modes", f.modes, modes},
							{"isDir", f.isDir, isDir},
							{"size", f.size, size},
						} {
							if !reflect.DeepEqual(v.want, v.got) {
								t.Errorf("%s: expected %v; got %v", v.desc, v.want, v.got)
							}
						}
					}

					t.Run("fs.ReadDir "+f.desc, func(t *testing.T) {
						des, err := s3fs.ReadDir(f.path)
						if err != nil {
							t.Fatalf("expected err to be nil: %v", err)
						}
						test(t, des)
					})

					t.Run("file.ReadDir "+f.desc, func(t *testing.T) {
						f, err := s3fs.Open(f.path)
						if err != nil {
							t.Fatalf("expected err to be nil: %v", err)
						}

						d, ok := f.(fs.ReadDirFile)
						if !ok {
							t.Fatal("expected file to be a directory")
						}

						des, err := d.ReadDir(-1)
						if err != nil && !errors.Is(err, io.EOF) {
							t.Fatalf("expected err to be nil: %v", err)
						}
						test(t, des)
					})
				}
			})

			t.Run("error", func(t *testing.T) {
				fixtures := []struct {
					desc string
					path string
					err  fs.PathError
				}{
					{
						desc: "invalid path",
						path: "/",
						err:  fs.PathError{Op: "readdir", Path: "/", Err: fs.ErrInvalid},
					},
					{
						desc: "does not exist",
						path: "notexist",
						err:  fs.PathError{Op: "readdir", Path: "notexist", Err: fs.ErrNotExist},
					},
					{
						desc: "does not exist",
						path: "dir1/notexist",
						err:  fs.PathError{Op: "readdir", Path: "dir1/notexist", Err: fs.ErrNotExist},
					},
					{
						desc: "readDir on a file",
						path: "dir1/file1.txt",
						err:  fs.PathError{Op: "readdir", Path: "dir1/file1.txt", Err: errors.New("not a dir")},
					},
				}

				for _, f := range fixtures {
					t.Run(f.desc, func(t *testing.T) {
						_, err := s3fs.ReadDir(f.path)

						var perr *fs.PathError
						if !errors.As(err, &perr) {
							t.Fatalf("expected err to be *fs.PathError; got %[1]T: %[1]v", err)
						}

						if perr.Op != f.err.Op {
							t.Errorf("want %v; got %v", f.err.Op, perr.Op)
						}

						if perr.Path != f.err.Path {
							t.Errorf("want %v; got %v", f.err.Path, perr.Path)
						}

						if perr.Err.Error() != f.err.Err.Error() {
							t.Errorf("want %v; got %v", f.err.Err.Error(), perr.Err.Error())
						}
					})
				}
			})
		})

		t.Run("subfs", func(t *testing.T) {
			t.Run("existing", func(t *testing.T) {
				fsys, err := fs.Sub(s3fs, "dir1/dir11")
				if err != nil {
					t.Fatal(err)
				}

				t.Run("fs.Stat", func(t *testing.T) {
					fi, err := fs.Stat(fsys, "file.txt")
					if err != nil {
						t.Fatal(err)
					}
					if fi.Name() != "file.txt" {
						t.Errorf("expected file.txt got %s", fi.Name())
					}

					t.Run("not exist", func(t *testing.T) {
						_, err = fs.Stat(fsys, "not-exist")
						var perr *fs.PathError
						if !errors.As(err, &perr) {
							t.Fatalf("expected err to be PathError: got %#v", err)
						}

						// currently we don't implement fs.SubFS.
						// fs.Sub calls open instead of Stat.
						if perr.Op != "open" {
							t.Errorf("expected op to be open; got %s", perr.Op)
						}
					})
				})

				t.Run("fs.ReadDir", func(t *testing.T) {
					files, err := fs.ReadDir(fsys, ".")
					if err != nil {
						t.Fatal(err)
					}

					if len(files) != 1 {
						t.Fatalf("expected 1 file in dir1/dir11; got %d", len(files))
					}
					if files[0].Name() != "file.txt" {
						t.Errorf("expected file to be file.txt; got %s", files[0].Name())
					}

					t.Run("not exist", func(t *testing.T) {
						_, err := fs.ReadDir(fsys, "not-exist")
						var perr *fs.PathError
						if !errors.As(err, &perr) {
							t.Fatalf("expected err to be PathError: got %#v", err)
						}

						if perr.Op != "readdir" {
							t.Errorf("expected op to be readdir; got %s", perr.Op)
						}
					})
				})

				t.Run("open", func(t *testing.T) {
					f, err := fsys.Open(".")
					if err != nil {
						t.Fatal(err)
					}
					defer f.Close()

					dir, ok := f.(fs.ReadDirFile)
					if !ok {
						t.Fatal("expected file to be a directory")
					}

					fi, err := dir.Stat()
					if err != nil {
						t.Fatal(err)
					}
					if fi.Name() != "dir11" {
						t.Errorf("expected dir name to bedir11; got %s", fi.Name())
					}

					files, err := dir.ReadDir(-1)
					if err != nil {
						t.Fatal(err)
					}

					if len(files) != 1 {
						t.Fatalf("expected 1 file in dir1/dir11; got %d", len(files))
					}
					if files[0].Name() != "file.txt" {
						t.Errorf("expected file to be file.txt; got %s", files[0].Name())
					}
				})
			})
		})
	}

	fixtures := []struct {
		desc string
		s3fs *s3fs.S3FS
	}{
		{desc: "standard", s3fs: s3fs.New(wrappedCl, *bucket)},
		{desc: "max keys = 1", s3fs: s3fs.New(&client{MaxKeys: ptr[int32](1), Client: wrappedCl}, *bucket)},
		{desc: "max keys = 2", s3fs: s3fs.New(&client{MaxKeys: ptr[int32](2), Client: wrappedCl}, *bucket)},
		{desc: "max keys = 3", s3fs: s3fs.New(&client{MaxKeys: ptr[int32](3), Client: wrappedCl}, *bucket)},
	}

	for _, f := range fixtures {
		f := f
		t.Run(f.desc, func(t *testing.T) {
			t.Parallel()
			testFn(t, f.s3fs)
		})
	}
}

func TestDirRead(t *testing.T) {
	type fileinfo struct {
		name  string
		isDir bool
	}

	tests := []struct {
		desc     string
		n        int
		outs     []s3.ListObjectsOutput
		expected [][]fileinfo
	}{
		{
			desc: "all in one request - dir first",
			n:    1,
			outs: []s3.ListObjectsOutput{
				newListOutput([]string{"a", "c", "e"}, []string{"b", "d", "f"}),
			},
			expected: [][]fileinfo{
				{{"a", true}},
				{{"b", false}},
				{{"c", true}},
				{{"d", false}},
				{{"e", true}},
				{{"f", false}},
			},
		},
		{
			desc: "all in one request - n = 0",
			n:    0,
			outs: []s3.ListObjectsOutput{
				newListOutput([]string{"a", "c", "e"}, []string{"b", "d", "f"}),
			},
			expected: [][]fileinfo{
				{
					{"a", true},
					{"b", false},
					{"c", true},
					{"d", false},
					{"e", true},
					{"f", false},
				},
			},
		},
		{
			desc: "all in one request - n = 2",
			n:    2,
			outs: []s3.ListObjectsOutput{
				newListOutput([]string{"a"}, nil),
				newListOutput([]string{"c"}, []string{"b", "d"}),
				newListOutput([]string{"e"}, nil),
				newListOutput(nil, []string{"f"}),
			},
			expected: [][]fileinfo{
				{
					{"a", true},
					{"b", false},
				},
				{
					{"c", true},
					{"d", false},
				},
				{
					{"e", true},
					{"f", false},
				},
			},
		},
		{
			desc: "one per request - dir first",
			n:    1,
			outs: []s3.ListObjectsOutput{
				newListOutput([]string{"a"}, nil),
				newListOutput(nil, []string{"b"}),
				newListOutput([]string{"c"}, []string{"d"}),
				newListOutput([]string{"e"}, nil),
				newListOutput(nil, []string{"f"}),
			},
			expected: [][]fileinfo{
				{{"a", true}},
				{{"b", false}},
				{{"c", true}},
				{{"d", false}},
				{{"e", true}},
				{{"f", false}},
			},
		},
		{
			desc: "all in one request - file first",
			n:    1,
			outs: []s3.ListObjectsOutput{
				newListOutput([]string{"b", "d", "f"}, []string{"a", "c", "e"}),
			},
			expected: [][]fileinfo{
				{{"a", false}},
				{{"b", true}},
				{{"c", false}},
				{{"d", true}},
				{{"e", false}},
				{{"f", true}},
			},
		},
		{
			desc: "with dir duplicates",
			n:    1,
			outs: []s3.ListObjectsOutput{
				newListOutput([]string{"a", "c"}, []string{"b"}),
				newListOutput([]string{"c", "e", "c"}, []string{"d"}),
				newListOutput([]string{"e", "a"}, []string{"f"}),
			},
			expected: [][]fileinfo{
				{{"a", true}},
				{{"b", false}},
				{{"c", true}},
				{{"d", false}},
				{{"e", true}},
				{{"f", false}},
			},
		},

		{
			desc: "all in one request - dirs only",
			n:    1,
			outs: []s3.ListObjectsOutput{
				newListOutput([]string{"a", "c", "e"}, nil),
			},
			expected: [][]fileinfo{
				{{"a", true}},
				{{"c", true}},
				{{"e", true}},
			},
		},
		{
			desc: "single dir per request - dirs only",
			n:    1,
			outs: []s3.ListObjectsOutput{
				newListOutput([]string{"a"}, nil),
				newListOutput([]string{"c"}, nil),
				newListOutput([]string{"e"}, nil),
			},
			expected: [][]fileinfo{
				{{"a", true}},
				{{"c", true}},
				{{"e", true}},
			},
		},
	}

	for _, test := range tests {
		t.Run(test.desc, func(t *testing.T) {
			f, err := s3fs.New(&mockClient{
				outs: test.outs,
			}, "test").Open(".")
			if err != nil {
				t.Fatal("expected err to be nil; got ", err)
			}

			fi, err := f.Stat()
			if err != nil {
				t.Fatal("expected err to be nil; got ", err)
			}

			if !fi.IsDir() {
				t.Fatal("expected the file to be a directory")
			}

			var fis [][]fileinfo
			for {
				files, err := f.(fs.ReadDirFile).ReadDir(test.n)
				if err != nil && !errors.Is(err, io.EOF) {
					t.Fatal("did not expect err:", err)
				}

				if len(files) > 0 {
					var out []fileinfo
					for _, f := range files {
						out = append(out, fileinfo{f.Name(), f.IsDir()})
					}
					fis = append(fis, out)
				}

				if test.n <= 0 || errors.Is(err, io.EOF) {
					break
				}
			}

			if !reflect.DeepEqual(fis, test.expected) {
				t.Errorf("want %v; got %v", test.expected, fis)
			}
		})
	}
}

type mockClient struct {
	s3fs.Client
	outs []s3.ListObjectsOutput
	i    int
}

func (c *mockClient) ListObjects(ctx context.Context, in *s3.ListObjectsInput, _ ...func(*s3.Options)) (*s3.ListObjectsOutput, error) {
	defer func() { c.i++ }()
	if c.i < len(c.outs) {
		return &c.outs[c.i], nil
	}

	return &s3.ListObjectsOutput{
		IsTruncated: ptr(false),
	}, nil
}

func newListOutput(dirs, files []string) (out s3.ListObjectsOutput) {
	for _, d := range dirs {
		out.CommonPrefixes = append(out.CommonPrefixes, types.CommonPrefix{
			Prefix: ptr(d),
		})
	}

	for _, f := range files {
		out.Contents = append(out.Contents, types.Object{
			Key:          ptr(f),
			Size:         ptr[int64](0),
			LastModified: ptr(time.Time{}),
		})
	}
	return out
}

type Client interface {
	s3fs.Client
}

func newClient(t *testing.T) (*s3.Client, Client) {
	t.Helper()

	cl := &http.Client{
		Transport: &http.Transport{
			TLSClientConfig: &tls.Config{
				InsecureSkipVerify: *skipVerify,
			},
		},
	}

	client := s3.New(s3.Options{
		BaseEndpoint: endpoint,
		Credentials: aws.CredentialsProviderFunc(func(ctx context.Context) (aws.Credentials, error) {
			return aws.Credentials{
				AccessKeyID:     accessKeyID,
				SecretAccessKey: secretKey,
			}, nil
		}),
		Region:       region,
		UsePathStyle: true,
		HTTPClient:   cl,
	})

	return client, &modTimeTruncateClient{&metricClient{client}}
}

func writeFile(t *testing.T, cl *s3.Client, bucket, name string, data []byte) {
	t.Helper()

	uploader := manager.NewUploader(cl)
	_, err := uploader.Upload(context.Background(), &s3.PutObjectInput{
		Body:   strings.NewReader(string(data)),
		Bucket: &bucket,
		Key:    &name,
	})
	if err != nil {
		t.Fatal(err)
	}
}

func deleteFile(t *testing.T, cl *s3.Client, bucket, name string) {
	t.Helper()

	_, err := cl.DeleteObject(
		context.Background(),
		&s3.DeleteObjectInput{
			Bucket: ptr(bucket),
			Key:    &name,
		})
	if err != nil {
		t.Fatal(err)
	}
}

func createBucket(t *testing.T, cl *s3.Client, bucket string) {
	t.Helper()

	_, err := cl.CreateBucket(context.Background(), &s3.CreateBucketInput{
		Bucket: &bucket,
	})
	if err != nil {
		var e *types.BucketAlreadyOwnedByYou
		if errors.As(err, &e) {
			return
		}
		t.Fatal(err)
	}
}

func cleanBucket(t *testing.T, cl *s3.Client, bucket string) {
	t.Helper()

	out, err := cl.ListObjects(
		context.Background(),
		&s3.ListObjectsInput{
			Bucket: ptr(bucket),
		})
	if err != nil {
		t.Fatal("failed to delete bucket:", err)
	}

	for _, o := range out.Contents {
		_, err := cl.DeleteObject(
			context.Background(),
			&s3.DeleteObjectInput{
				Bucket: ptr(bucket),
				Key:    o.Key,
			})
		if err != nil {
			t.Error("failed to delete file:", err)
		}
	}
}

func envDefault(env, def string) string {
	if os.Getenv(env) == "" {
		return def
	}
	return os.Getenv(env)
}

type client struct {
	MaxKeys *int32
	s3fs.Client
}

func (c *client) ListObjects(ctx context.Context, in *s3.ListObjectsInput, _ ...func(*s3.Options)) (*s3.ListObjectsOutput, error) {
	if c.MaxKeys != nil {
		in.MaxKeys = c.MaxKeys
	}
	return c.Client.ListObjects(ctx, in)
}

type modTimeTruncateClient struct {
	Client
}

// Minio returns modTime that includes microseconds if data comes from ListObjects
// while data coming from GetObject's modTimes are accurate down to seconds.
// To make this test pass while using Minio we build this client that truncates
// modTimes to Second.
func (c *modTimeTruncateClient) ListObjects(ctx context.Context, in *s3.ListObjectsInput, _ ...func(*s3.Options)) (*s3.ListObjectsOutput, error) {
	out, err := c.Client.ListObjects(context.Background(), in)
	if err != nil {
		return out, err
	}

	for i, o := range out.Contents {
		out.Contents[i].LastModified = ptr(o.LastModified.Truncate(time.Second))
	}
	return out, err
}

var (
	// global metrics for this test.
	listC int64
	getC  int64
)

type metricClient struct {
	Client
}

func (c *metricClient) ListObjects(ctx context.Context, in *s3.ListObjectsInput, _ ...func(*s3.Options)) (*s3.ListObjectsOutput, error) {
	atomic.AddInt64(&listC, 1)
	return c.Client.ListObjects(ctx, in)
}

func (c *metricClient) GetObject(ctx context.Context, in *s3.GetObjectInput, optFns ...func(*s3.Options)) (*s3.GetObjectOutput, error) {
	atomic.AddInt64(&getC, 1)
	return c.Client.GetObject(context.Background(), in)
}

func ptr[T any](v T) *T {
	return &v
}


================================================
FILE: go.mod
================================================
module github.com/jszwec/s3fs/v2

go 1.21

require (
	github.com/aws/aws-sdk-go-v2 v1.24.0
	github.com/aws/aws-sdk-go-v2/feature/s3/manager v1.15.7
	github.com/aws/aws-sdk-go-v2/service/s3 v1.47.5
)

require (
	github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.5.4 // indirect
	github.com/aws/aws-sdk-go-v2/internal/configsources v1.2.9 // indirect
	github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.5.9 // indirect
	github.com/aws/aws-sdk-go-v2/internal/v4a v1.2.9 // indirect
	github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.10.4 // indirect
	github.com/aws/aws-sdk-go-v2/service/internal/checksum v1.2.9 // indirect
	github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.10.9 // indirect
	github.com/aws/aws-sdk-go-v2/service/internal/s3shared v1.16.9 // indirect
	github.com/aws/smithy-go v1.19.0 // indirect
	github.com/jmespath/go-jmespath v0.4.0 // indirect
)


================================================
FILE: go.sum
================================================
github.com/aws/aws-sdk-go-v2 v1.24.0 h1:890+mqQ+hTpNuw0gGP6/4akolQkSToDJgHfQE7AwGuk=
github.com/aws/aws-sdk-go-v2 v1.24.0/go.mod h1:LNh45Br1YAkEKaAqvmE1m8FUx6a5b/V0oAKV7of29b4=
github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.5.4 h1:OCs21ST2LrepDfD3lwlQiOqIGp6JiEUqG84GzTDoyJs=
github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.5.4/go.mod h1:usURWEKSNNAcAZuzRn/9ZYPT8aZQkR7xcCtunK/LkJo=
github.com/aws/aws-sdk-go-v2/config v1.26.1 h1:z6DqMxclFGL3Zfo+4Q0rLnAZ6yVkzCRxhRMsiRQnD1o=
github.com/aws/aws-sdk-go-v2/config v1.26.1/go.mod h1:ZB+CuKHRbb5v5F0oJtGdhFTelmrxd4iWO1lf0rQwSAg=
github.com/aws/aws-sdk-go-v2/credentials v1.16.12 h1:v/WgB8NxprNvr5inKIiVVrXPuuTegM+K8nncFkr1usU=
github.com/aws/aws-sdk-go-v2/credentials v1.16.12/go.mod h1:X21k0FjEJe+/pauud82HYiQbEr9jRKY3kXEIQ4hXeTQ=
github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.14.10 h1:w98BT5w+ao1/r5sUuiH6JkVzjowOKeOJRHERyy1vh58=
github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.14.10/go.mod h1:K2WGI7vUvkIv1HoNbfBA1bvIZ+9kL3YVmWxeKuLQsiw=
github.com/aws/aws-sdk-go-v2/feature/s3/manager v1.15.7 h1:FnLf60PtjXp8ZOzQfhJVsqF0OtYKQZWQfqOLshh8YXg=
github.com/aws/aws-sdk-go-v2/feature/s3/manager v1.15.7/go.mod h1:tDVvl8hyU6E9B8TrnNrZQEVkQlB8hjJwcgpPhgtlnNg=
github.com/aws/aws-sdk-go-v2/internal/configsources v1.2.9 h1:v+HbZaCGmOwnTTVS86Fleq0vPzOd7tnJGbFhP0stNLs=
github.com/aws/aws-sdk-go-v2/internal/configsources v1.2.9/go.mod h1:Xjqy+Nyj7VDLBtCMkQYOw1QYfAEZCVLrfI0ezve8wd4=
github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.5.9 h1:N94sVhRACtXyVcjXxrwK1SKFIJrA9pOJ5yu2eSHnmls=
github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.5.9/go.mod h1:hqamLz7g1/4EJP+GH5NBhcUMLjW+gKLQabgyz6/7WAU=
github.com/aws/aws-sdk-go-v2/internal/ini v1.7.2 h1:GrSw8s0Gs/5zZ0SX+gX4zQjRnRsMJDJ2sLur1gRBhEM=
github.com/aws/aws-sdk-go-v2/internal/ini v1.7.2/go.mod h1:6fQQgfuGmw8Al/3M2IgIllycxV7ZW7WCdVSqfBeUiCY=
github.com/aws/aws-sdk-go-v2/internal/v4a v1.2.9 h1:ugD6qzjYtB7zM5PN/ZIeaAIyefPaD82G8+SJopgvUpw=
github.com/aws/aws-sdk-go-v2/internal/v4a v1.2.9/go.mod h1:YD0aYBWCrPENpHolhKw2XDlTIWae2GKXT1T4o6N6hiM=
github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.10.4 h1:/b31bi3YVNlkzkBrm9LfpaKoaYZUxIAj4sHfOTmLfqw=
github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.10.4/go.mod h1:2aGXHFmbInwgP9ZfpmdIfOELL79zhdNYNmReK8qDfdQ=
github.com/aws/aws-sdk-go-v2/service/internal/checksum v1.2.9 h1:/90OR2XbSYfXucBMJ4U14wrjlfleq/0SB6dZDPncgmo=
github.com/aws/aws-sdk-go-v2/service/internal/checksum v1.2.9/go.mod h1:dN/Of9/fNZet7UrQQ6kTDo/VSwKPIq94vjlU16bRARc=
github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.10.9 h1:Nf2sHxjMJR8CSImIVCONRi4g0Su3J+TSTbS7G0pUeMU=
github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.10.9/go.mod h1:idky4TER38YIjr2cADF1/ugFMKvZV7p//pVeV5LZbF0=
github.com/aws/aws-sdk-go-v2/service/internal/s3shared v1.16.9 h1:iEAeF6YC3l4FzlJPP9H3Ko1TXpdjdqWffxXjp8SY6uk=
github.com/aws/aws-sdk-go-v2/service/internal/s3shared v1.16.9/go.mod h1:kjsXoK23q9Z/tLBrckZLLyvjhZoS+AGrzqzUfEClvMM=
github.com/aws/aws-sdk-go-v2/service/s3 v1.47.5 h1:Keso8lIOS+IzI2MkPZyK6G0LYcK3My2LQ+T5bxghEAY=
github.com/aws/aws-sdk-go-v2/service/s3 v1.47.5/go.mod h1:vADO6Jn+Rq4nDtfwNjhgR84qkZwiC6FqCaXdw/kYwjA=
github.com/aws/aws-sdk-go-v2/service/sso v1.18.5 h1:ldSFWz9tEHAwHNmjx2Cvy1MjP5/L9kNoR0skc6wyOOM=
github.com/aws/aws-sdk-go-v2/service/sso v1.18.5/go.mod h1:CaFfXLYL376jgbP7VKC96uFcU8Rlavak0UlAwk1Dlhc=
github.com/aws/aws-sdk-go-v2/service/ssooidc v1.21.5 h1:2k9KmFawS63euAkY4/ixVNsYYwrwnd5fIvgEKkfZFNM=
github.com/aws/aws-sdk-go-v2/service/ssooidc v1.21.5/go.mod h1:W+nd4wWDVkSUIox9bacmkBP5NMFQeTJ/xqNabpzSR38=
github.com/aws/aws-sdk-go-v2/service/sts v1.26.5 h1:5UYvv8JUvllZsRnfrcMQ+hJ9jNICmcgKPAO1CER25Wg=
github.com/aws/aws-sdk-go-v2/service/sts v1.26.5/go.mod h1:XX5gh4CB7wAs4KhcF46G6C8a2i7eupU19dcAAE+EydU=
github.com/aws/smithy-go v1.19.0 h1:KWFKQV80DpP3vJrrA9sVAHQ5gc2z8i4EzrLhLlWXcBM=
github.com/aws/smithy-go v1.19.0/go.mod h1:NukqUGpCZIILqqiV0NIjeFh24kd/FAa4beRb6nbIUPE=
github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
github.com/google/go-cmp v0.5.8/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
github.com/jmespath/go-jmespath v0.4.0 h1:BEgLn5cpjn8UN1mAw4NjwDrS35OdebyEtFe+9YPoQUg=
github.com/jmespath/go-jmespath v0.4.0/go.mod h1:T8mJZnbsbmF+m6zOOFylbeCJqk5+pHWvzYPziyZiYoo=
github.com/jmespath/go-jmespath/internal/testify v1.5.1 h1:shLQSRRSCCPj3f2gpwzGwWFoC7ycTf1rcQZHOlsJ6N8=
github.com/jmespath/go-jmespath/internal/testify v1.5.1/go.mod h1:L3OGu8Wl2/fWfCI6z80xFu9LTZmf1ZRjMHUOPmWr69U=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=


================================================
FILE: test/localstack/docker-compose.yml
================================================
version: '3.8'

services:
  localstack:
    container_name: "localstack"
    image: localstack/localstack:0.14.0
    network_mode: bridge
    ports:
      - "4566:4566"
      - "4571:4571"
    environment:
      - SERVICES=s3

================================================
FILE: test/minio/docker-compose.yml
================================================
version: '3.8'

services:
  minio:
    image: minio/minio
    ports:
      - "9000:9000"
    environment:
      MINIO_ROOT_USER: minioadmin
      MINIO_ROOT_PASSWORD: minioadmin
    command: server /data
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:9000/minio/health/live"]
      interval: 30s
      timeout: 20s
      retries: 3