fix linting issues

archive.go

@@ -260,7 +260,7 @@ func (r *bufferedReader) Read(p []byte) (int, error) {
 		return 0, io.EOF
 	}
 	n, err := r.buf.Read(p)
-	if err == io.EOF {
+	if errors.Is(err, io.EOF) {
 		r.buf.Reset(nil)
 		bufioReader32KPool.Put(r.buf)
 		r.buf = nil
@@ -279,7 +279,7 @@ func (r *bufferedReader) Peek(n int) ([]byte, error) {
 func DecompressStream(archive io.Reader) (io.ReadCloser, error) {
 	buf := newBufferedReader(archive)
 	bs, err := buf.Peek(10)
-	if err != nil && err != io.EOF {
+	if err != nil && !errors.Is(err, io.EOF) {
 		// Note: we'll ignore any io.EOF error because there are some odd
 		// cases where the layer.tar file will be empty (zero bytes) and
 		// that results in an io.EOF from the Peek() call. So, in those
@@ -344,7 +344,7 @@ func DecompressStream(archive io.Reader) (io.ReadCloser, error) {
 			},
 		}, nil
 	default:
-		return nil, fmt.Errorf("Unsupported compression format %s", (&compression).Extension())
+		return nil, fmt.Errorf("unsupported compression format: %s", (&compression).Extension())
 	}
 }
 
@@ -364,9 +364,9 @@ func CompressStream(dest io.Writer, compression Compression) (io.WriteCloser, er
 	case Bzip2, Xz:
 		// archive/bzip2 does not support writing, and there is no xz support at all
 		// However, this is not a problem as docker only currently generates gzipped tars
-		return nil, fmt.Errorf("Unsupported compression format %s", (&compression).Extension())
+		return nil, fmt.Errorf("unsupported compression format: %s", (&compression).Extension())
 	default:
-		return nil, fmt.Errorf("Unsupported compression format %s", (&compression).Extension())
+		return nil, fmt.Errorf("unsupported compression format: %s", (&compression).Extension())
 	}
 }
 
@@ -416,7 +416,7 @@ func ReplaceFileTarWrapper(inputTarStream io.ReadCloser, mods map[string]TarModi
 		var originalHeader *tar.Header
 		for {
 			originalHeader, err = tarReader.Next()
-			if err == io.EOF {
+			if errors.Is(err, io.EOF) {
 				break
 			}
 			if err != nil {
@@ -768,7 +768,7 @@ func createTarFile(path, extractDir string, hdr *tar.Header, reader io.Reader, o
 	case tar.TypeDir:
 		// Create directory unless it exists as a directory already.
 		// In that case we just want to merge the two
-		if fi, err := os.Lstat(path); !(err == nil && fi.IsDir()) {
+		if fi, err := os.Lstat(path); err != nil || !fi.IsDir() {
 			if err := os.Mkdir(path, hdrInfo.Mode()); err != nil {
 				return err
 			}
@@ -1031,7 +1031,8 @@ func (t *Tarballer) Do() {
 		)
 
 		walkRoot := getWalkRoot(t.srcPath, include)
-		filepath.WalkDir(walkRoot, func(filePath string, f os.DirEntry, err error) error {
+		// TODO(thaJeztah): should this error be handled?
+		_ = filepath.WalkDir(walkRoot, func(filePath string, f os.DirEntry, err error) error {
 			if err != nil {
 				log.G(context.TODO()).Errorf("Tar: Can't stat file %s to tar: %s", t.srcPath, err)
 				return nil
@@ -1135,7 +1136,7 @@ func (t *Tarballer) Do() {
 			if err := ta.addTarFile(filePath, relFilePath); err != nil {
 				log.G(context.TODO()).Errorf("Can't add file %s to tar: %s", filePath, err)
 				// if pipe is broken, stop writing tar stream to it
-				if err == io.ErrClosedPipe {
+				if errors.Is(err, io.ErrClosedPipe) {
 					return err
 				}
 			}
@@ -1155,7 +1156,7 @@ func Unpack(decompressedArchive io.Reader, dest string, options *TarOptions) err
 loop:
 	for {
 		hdr, err := tr.Next()
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			// end of tar archive
 			break
 		}
@@ -1217,7 +1218,7 @@ loop:
 				continue
 			}
 
-			if !(fi.IsDir() && hdr.Typeflag == tar.TypeDir) {
+			if !fi.IsDir() || hdr.Typeflag != tar.TypeDir {
 				if err := os.RemoveAll(path); err != nil {
 					return err
 				}
@@ -1309,7 +1310,7 @@ func UntarUncompressed(tarArchive io.Reader, dest string, options *TarOptions) e
 // Handler for teasing out the automatic decompression
 func untarHandler(tarArchive io.Reader, dest string, options *TarOptions, decompress bool) error {
 	if tarArchive == nil {
-		return fmt.Errorf("Empty archive")
+		return errors.New("empty archive")
 	}
 	dest = filepath.Clean(dest)
 	if options == nil {
@@ -1393,7 +1394,7 @@ func (archiver *Archiver) CopyFileWithTar(src, dst string) (err error) {
 	}
 
 	if srcSt.IsDir() {
-		return fmt.Errorf("Can't copy a directory")
+		return errors.New("can't copy a directory")
 	}
 
 	// Clean up the trailing slash. This must be done in an operating
@@ -1492,9 +1493,9 @@ func cmdStream(cmd *exec.Cmd, input io.Reader) (io.ReadCloser, error) {
 	// Copy stdout to the returned pipe
 	go func() {
 		if err := cmd.Wait(); err != nil {
-			pipeW.CloseWithError(fmt.Errorf("%s: %s", err, errBuf.String()))
+			_ = pipeW.CloseWithError(fmt.Errorf("%w: %s", err, errBuf.String()))
 		} else {
-			pipeW.Close()
+			_ = pipeW.Close()
 		}
 		close(done)
 	}()

archive_linux_test.go

@@ -3,6 +3,7 @@ package archive
 import (
 	"archive/tar"
 	"bytes"
+	"errors"
 	"io"
 	"os"
 	"path/filepath"
@@ -119,7 +120,7 @@ func TestOverlayTarUntar(t *testing.T) {
 	rdr := tar.NewReader(bytes.NewReader(archive))
 	for {
 		h, err := rdr.Next()
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			break
 		}
 		assert.NilError(t, err)

archive_test.go

@@ -4,6 +4,7 @@ import (
 	"archive/tar"
 	"bytes"
 	"compress/gzip"
+	"errors"
 	"fmt"
 	"io"
 	"io/fs"
@@ -479,22 +480,20 @@ func TestCopyWithTarSrcFile(t *testing.T) {
 	dest := filepath.Join(folder, "dest")
 	srcFolder := filepath.Join(folder, "src")
 	src := filepath.Join(folder, filepath.Join("src", "src"))
-	err := os.MkdirAll(srcFolder, 0o740)
-	if err != nil {
+	if err := os.MkdirAll(srcFolder, 0o740); err != nil {
 		t.Fatal(err)
 	}
-	err = os.MkdirAll(dest, 0o740)
-	if err != nil {
+	if err := os.MkdirAll(dest, 0o740); err != nil {
 		t.Fatal(err)
 	}
-	os.WriteFile(src, []byte("content"), 0o777)
-	err = defaultCopyWithTar(src, dest)
-	if err != nil {
+	if err := os.WriteFile(src, []byte("content"), 0o777); err != nil {
+		t.Fatal(err)
+	}
+	if err := defaultCopyWithTar(src, dest); err != nil {
 		t.Fatalf("archiver.CopyWithTar shouldn't throw an error, %s.", err)
 	}
-	_, err = os.Stat(dest)
 	// FIXME Check the content
-	if err != nil {
+	if _, err := os.Stat(dest); err != nil {
 		t.Fatalf("Destination file should be the same as the source.")
 	}
 }
@@ -504,22 +503,20 @@ func TestCopyWithTarSrcFolder(t *testing.T) {
 	folder := t.TempDir()
 	dest := filepath.Join(folder, "dest")
 	src := filepath.Join(folder, filepath.Join("src", "folder"))
-	err := os.MkdirAll(src, 0o740)
-	if err != nil {
+	if err := os.MkdirAll(src, 0o740); err != nil {
 		t.Fatal(err)
 	}
-	err = os.MkdirAll(dest, 0o740)
-	if err != nil {
+	if err := os.MkdirAll(dest, 0o740); err != nil {
 		t.Fatal(err)
 	}
-	os.WriteFile(filepath.Join(src, "file"), []byte("content"), 0o777)
-	err = defaultCopyWithTar(src, dest)
-	if err != nil {
+	if err := os.WriteFile(filepath.Join(src, "file"), []byte("content"), 0o777); err != nil {
+		t.Fatal(err)
+	}
+	if err := defaultCopyWithTar(src, dest); err != nil {
 		t.Fatalf("archiver.CopyWithTar shouldn't throw an error, %s.", err)
 	}
-	_, err = os.Stat(dest)
 	// FIXME Check the content (the file inside)
-	if err != nil {
+	if _, err := os.Stat(dest); err != nil {
 		t.Fatalf("Destination folder should contain the source file but did not.")
 	}
 }
@@ -580,21 +577,19 @@ func TestCopyFileWithTarSrcFile(t *testing.T) {
 	dest := filepath.Join(folder, "dest")
 	srcFolder := filepath.Join(folder, "src")
 	src := filepath.Join(folder, filepath.Join("src", "src"))
-	err := os.MkdirAll(srcFolder, 0o740)
-	if err != nil {
+	if err := os.MkdirAll(srcFolder, 0o740); err != nil {
 		t.Fatal(err)
 	}
-	err = os.MkdirAll(dest, 0o740)
-	if err != nil {
+	if err := os.MkdirAll(dest, 0o740); err != nil {
 		t.Fatal(err)
 	}
-	os.WriteFile(src, []byte("content"), 0o777)
-	err = defaultCopyWithTar(src, dest+"/")
-	if err != nil {
+	if err := os.WriteFile(src, []byte("content"), 0o777); err != nil {
+		t.Fatal(err)
+	}
+	if err := defaultCopyWithTar(src, dest+"/"); err != nil {
 		t.Fatalf("archiver.CopyFileWithTar shouldn't throw an error, %s.", err)
 	}
-	_, err = os.Stat(dest)
-	if err != nil {
+	if _, err := os.Stat(dest); err != nil {
 		t.Fatalf("Destination folder should contain the source file but did not.")
 	}
 }
@@ -655,9 +650,9 @@ func tarUntar(t *testing.T, origin string, options *TarOptions) ([]Change, error
 	wrap := io.MultiReader(bytes.NewReader(buf), archive)
 
 	detectedCompression := DetectCompression(buf)
-	compression := options.Compression
-	if detectedCompression.Extension() != compression.Extension() {
-		return nil, fmt.Errorf("Wrong compression detected. Actual compression: %s, found %s", compression.Extension(), detectedCompression.Extension())
+	expected := options.Compression
+	if detectedCompression.Extension() != expected.Extension() {
+		return nil, fmt.Errorf("wrong compression detected; expected: %s, got: %s", expected.Extension(), detectedCompression.Extension())
 	}
 
 	tmp := t.TempDir()
@@ -766,7 +761,7 @@ func TestTarWithOptionsChownOptsAlwaysOverridesIdPair(t *testing.T) {
 			defer reader.Close()
 			for {
 				hdr, err := tr.Next()
-				if err == io.EOF {
+				if errors.Is(err, io.EOF) {
 					// end of tar archive
 					break
 				}
@@ -838,7 +833,7 @@ func TestUntarUstarGnuConflict(t *testing.T) {
 	// Iterate through the files in the archive.
 	for {
 		hdr, err := tr.Next()
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			// end of tar archive
 			break
 		}

archive_unix_test.go

@@ -5,6 +5,7 @@ package archive
 import (
 	"archive/tar"
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -259,7 +260,7 @@ func TestTarUntarWithXattr(t *testing.T) {
 	rdr := tar.NewReader(tarball)
 	for {
 		h, err := rdr.Next()
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			break
 		}
 		assert.NilError(t, err)

archive_windows.go

@@ -41,11 +41,6 @@ func chmodTarEntry(perm os.FileMode) os.FileMode {
 	return perm | 0o111
 }
 
-func setHeaderForSpecialDevice(hdr *tar.Header, name string, stat interface{}) (err error) {
-	// do nothing. no notion of Rdev, Nlink in stat on Windows
-	return
-}
-
 func getInodeFromStat(stat interface{}) (uint64, error) {
 	// do nothing. no notion of Inode in stat on Windows
 	return 0, nil

archive_windows_test.go

@@ -21,11 +21,12 @@ func TestCopyFileWithInvalidDest(t *testing.T) {
 	dest := "c:dest"
 	srcFolder := filepath.Join(folder, "src")
 	src := filepath.Join(folder, "src", "src")
-	err = os.MkdirAll(srcFolder, 0o740)
-	if err != nil {
+	if err := os.MkdirAll(srcFolder, 0o740); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(src, []byte("content"), 0o777); err != nil {
 		t.Fatal(err)
 	}
-	os.WriteFile(src, []byte("content"), 0o777)
 	err = defaultCopyWithTar(src, dest)
 	if err == nil {
 		t.Fatalf("archiver.CopyWithTar should throw an error on invalid dest.")

changes.go

@@ -75,7 +75,7 @@ func sameFsTime(a, b time.Time) bool {
 // Changes walks the path rw and determines changes for the files in the path,
 // with respect to the parent layers
 func Changes(layers []string, rw string) ([]Change, error) {
-	return changes(layers, rw, aufsDeletedFile, aufsMetadataSkip)
+	return collectChanges(layers, rw, aufsDeletedFile, aufsMetadataSkip)
 }
 
 func aufsMetadataSkip(path string) (skip bool, err error) {
@@ -103,7 +103,7 @@ type (
 	deleteChange func(string, string, os.FileInfo) (string, error)
 )
 
-func changes(layers []string, rw string, dc deleteChange, sc skipChange) ([]Change, error) {
+func collectChanges(layers []string, rw string, dc deleteChange, sc skipChange) ([]Change, error) {
 	var (
 		changes     []Change
 		changedDirs = make(map[string]struct{})

changes_linux.go

@@ -132,14 +132,7 @@ func (w *walker) walk(path string, i1, i2 os.FileInfo) (err error) {
 	ix1 := 0
 	ix2 := 0
 
-	for {
-		if ix1 >= len(names1) {
-			break
-		}
-		if ix2 >= len(names2) {
-			break
-		}
-
+	for ix1 < len(names1) && ix2 < len(names2) {
 		ni1 := names1[ix1]
 		ni2 := names2[ix2]
 

changes_posix_test.go

@@ -2,6 +2,7 @@ package archive
 
 import (
 	"archive/tar"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -112,7 +113,7 @@ func walkHeaders(r io.Reader) ([]tar.Header, error) {
 	for {
 		hdr, err := t.Next()
 		if err != nil {
-			if err == io.EOF {
+			if errors.Is(err, io.EOF) {
 				break
 			}
 			return headers, err