Refactor making archive internal file path (fixes #109)

archiver.go

@@ -232,3 +232,35 @@ func folderNameFromFileName(filename string) string {
 	}
 	return base
 }
+
+// makeBaseDir returns the base directory to use for storing files in an
+// archive. topLevelFolder should be the name of the top-level folder of
+// the archive (if there is one), and sourceInfo is the file info obtained
+// by calling os.Stat on the source file or directory to include in the
+// archive.
+func makeBaseDir(topLevelFolder string, sourceInfo os.FileInfo) string {
+	var baseDir string
+	if topLevelFolder != "" {
+		baseDir = topLevelFolder
+	}
+	if sourceInfo.IsDir() {
+		baseDir = path.Join(baseDir, sourceInfo.Name())
+	}
+	return baseDir
+}
+
+// makeNameInArchive returns the filename for the file given by fpath to be used within
+// the archive. sourceInfo is the info obtained by calling os.Stat on source, and baseDir
+// is the base directory obtained by calling makeBaseDir. fpath should be the unaltered
+// file path of the file given to a filepath.WalkFunc.
+func makeNameInArchive(sourceInfo os.FileInfo, source, baseDir, fpath string) (string, error) {
+	name := fpath
+	if sourceInfo.IsDir() {
+		var err error
+		name, err = filepath.Rel(source, fpath)
+		if err != nil {
+			return "", err
+		}
+	}
+	return path.Join(baseDir, filepath.ToSlash(name)), nil
+}

archiver_test.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"path/filepath"
 	"testing"
+	"time"
 )
 
 func TestWithin(t *testing.T) {
@@ -138,6 +139,94 @@ func TestMultipleTopLevels(t *testing.T) {
 	}
 }
 
+func TestMakeBaseDir(t *testing.T) {
+	for i, tc := range []struct {
+		topLevelFolder string
+		sourceInfo     fakeFileInfo
+		expect         string
+	}{
+		{
+			topLevelFolder: "",
+			sourceInfo:     fakeFileInfo{isDir: false},
+			expect:         "",
+		},
+		{
+			topLevelFolder: "foo",
+			sourceInfo:     fakeFileInfo{isDir: false},
+			expect:         "foo",
+		},
+		{
+			topLevelFolder: "",
+			sourceInfo:     fakeFileInfo{isDir: true, name: "bar"},
+			expect:         "bar",
+		},
+		{
+			topLevelFolder: "foo",
+			sourceInfo:     fakeFileInfo{isDir: true, name: "bar"},
+			expect:         "foo/bar",
+		},
+	} {
+		actual := makeBaseDir(tc.topLevelFolder, tc.sourceInfo)
+		if actual != tc.expect {
+			t.Errorf("Test %d: Expected '%s' but got '%s'", i, tc.expect, actual)
+		}
+	}
+}
+
+func TestMakeNameInArchive(t *testing.T) {
+	for i, tc := range []struct {
+		sourceInfo fakeFileInfo
+		source     string
+		baseDir    string
+		fpath      string
+		expect     string
+	}{
+		{
+			sourceInfo: fakeFileInfo{isDir: false},
+			source:     "foo.txt",
+			baseDir:    "",
+			fpath:      "foo.txt",
+			expect:     "foo.txt",
+		},
+		{
+			sourceInfo: fakeFileInfo{isDir: false},
+			source:     "foo.txt",
+			baseDir:    "base",
+			fpath:      "foo.txt",
+			expect:     "base/foo.txt",
+		},
+		{
+			sourceInfo: fakeFileInfo{isDir: false},
+			source:     "foo/bar.txt",
+			baseDir:    "",
+			fpath:      "foo/bar.txt",
+			expect:     "foo/bar.txt",
+		},
+		{
+			sourceInfo: fakeFileInfo{isDir: false},
+			source:     "foo/bar.txt",
+			baseDir:    "base",
+			fpath:      "foo/bar.txt",
+			expect:     "base/foo/bar.txt",
+		},
+		{
+			sourceInfo: fakeFileInfo{isDir: true},
+			source:     "foo/bar",
+			baseDir:    "bar",
+			fpath:      "foo/bar",
+			expect:     "bar",
+		},
+	} {
+		actual, err := makeNameInArchive(tc.sourceInfo, tc.source, tc.baseDir, tc.fpath)
+		if err != nil {
+			t.Errorf("Test %d: Got error: %v", i, err)
+		}
+		if actual != tc.expect {
+			t.Errorf("Test %d: Expected '%s' but got '%s'", i, tc.expect, actual)
+		}
+	}
+}
+
 func TestArchiveUnarchive(t *testing.T) {
 	for _, af := range archiveFormats {
 		au, ok := af.(archiverUnarchiver)
@@ -288,3 +377,19 @@ type archiverUnarchiver interface {
 	Archiver
 	Unarchiver
 }
+
+type fakeFileInfo struct {
+	name    string
+	size    int64
+	mode    os.FileMode
+	modTime time.Time
+	isDir   bool
+	sys     interface{}
+}
+
+func (ffi fakeFileInfo) Name() string       { return ffi.name }
+func (ffi fakeFileInfo) Size() int64        { return ffi.size }
+func (ffi fakeFileInfo) Mode() os.FileMode  { return ffi.mode }
+func (ffi fakeFileInfo) ModTime() time.Time { return ffi.modTime }
+func (ffi fakeFileInfo) IsDir() bool        { return ffi.isDir }
+func (ffi fakeFileInfo) Sys() interface{}   { return ffi.sys }

tar.go

@@ -249,14 +249,7 @@ func (t *Tar) writeWalk(source, topLevelFolder, destination string) error {
 	if err != nil {
 		return fmt.Errorf("%s: getting absolute path of destination %s: %v", source, destination, err)
 	}
-
-	var baseDir string
-	if topLevelFolder != "" {
-		baseDir = topLevelFolder
-	}
-	if sourceInfo.IsDir() {
-		baseDir = path.Join(baseDir, sourceInfo.Name())
-	}
+	baseDir := makeBaseDir(topLevelFolder, sourceInfo)
 
 	return filepath.Walk(source, func(fpath string, info os.FileInfo, err error) error {
 		handleErr := func(err error) error {
@@ -282,12 +275,11 @@ func (t *Tar) writeWalk(source, topLevelFolder, destination string) error {
 			return nil
 		}
 
-		// build the name to be used in the archive
-		name, err := filepath.Rel(source, fpath)
+		// build the name to be used within the archive
+		nameInArchive, err := makeNameInArchive(sourceInfo, source, baseDir, fpath)
 		if err != nil {
 			return handleErr(err)
 		}
-		nameInArchive := path.Join(baseDir, filepath.ToSlash(name))
 
 		file, err := os.Open(fpath)
 		if err != nil {
@@ -344,7 +336,6 @@ func (t *Tar) Write(f File) error {
 	if f.ReadCloser == nil {
 		return fmt.Errorf("%s: no way to read file contents", f.Name())
 	}
-
 	hdr, err := tar.FileInfoHeader(f, f.Name())
 	if err != nil {
 		return fmt.Errorf("%s: making header: %v", f.Name(), err)

zip.go

@@ -207,14 +207,7 @@ func (z *Zip) writeWalk(source, topLevelFolder, destination string) error {
 	if err != nil {
 		return fmt.Errorf("%s: getting absolute path of destination %s: %v", source, destination, err)
 	}
-
-	var baseDir string
-	if topLevelFolder != "" {
-		baseDir = topLevelFolder
-	}
-	if sourceInfo.IsDir() {
-		baseDir = path.Join(baseDir, sourceInfo.Name())
-	}
+	baseDir := makeBaseDir(topLevelFolder, sourceInfo)
 
 	return filepath.Walk(source, func(fpath string, info os.FileInfo, err error) error {
 		handleErr := func(err error) error {
@@ -242,11 +235,10 @@ func (z *Zip) writeWalk(source, topLevelFolder, destination string) error {
 		}
 
 		// build the name to be used within the archive
-		name, err := filepath.Rel(source, fpath)
+		nameInArchive, err := makeNameInArchive(sourceInfo, source, baseDir, fpath)
 		if err != nil {
 			return handleErr(err)
 		}
-		nameInArchive := path.Join(baseDir, filepath.ToSlash(name))
 
 		file, err := os.Open(fpath)
 		if err != nil {