WIP

Signed-off-by: Paulo Gomes <[email protected]>

fixtures.go

@@ -13,7 +13,7 @@ import (
 	"github.com/go-git/go-git-fixtures/v4/internal/tgz"
 )
 
-var Filesystem = embedfs.New(&data, "data")
+var Filesystem = embedfs.New(&data, "data/")
 
 //go:embed data
 var data embed.FS

fixtures_options.go

@@ -47,7 +47,7 @@ func WithMemFS() Option {
 func WithTargetDir(dirName func() string) Option {
 	return func(o *options) {
 		o.fsFactory = func() (billy.Filesystem, error) {
-			return osfs.New(dirName(), osfs.WithBoundOS()), nil
+			return osfs.New(dirName(), osfs.WithChrootOS()), nil
 		}
 	}
 }

internal/embedfs/embed.go

@@ -9,31 +9,47 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
+	"strings"
 	"sync"
 
 	"github.com/go-git/go-billy/v5"
-	"github.com/go-git/go-billy/v5/helper/chroot"
 	"github.com/go-git/go-billy/v5/memfs"
 )
 
 type Embed struct {
 	underlying *embed.FS
+	base       string
 }
 
-func New(efs *embed.FS, path string) billy.Filesystem {
+func New(efs *embed.FS, base string) billy.Filesystem {
 	fs := &Embed{
 		underlying: efs,
+		base:       base,
 	}
 
 	if efs == nil {
 		fs.underlying = &embed.FS{}
 	}
 
-	return chroot.New(fs, path)
+	return fs
+}
+
+func (fs *Embed) Chroot(path string) (billy.Filesystem, error) {
+	fs.base = fs.Join(fs.base, path)
+
+	return fs, nil
+}
+
+func (fs *Embed) Root() string {
+	return fs.base
+}
+
+func (fs *Embed) path(filename string) string {
+	return fs.Join(fs.base, filename)
 }
 
 func (fs *Embed) Stat(filename string) (os.FileInfo, error) {
-	f, err := fs.underlying.Open(filename)
+	f, err := fs.underlying.Open(fs.path(filename))
 	if err != nil {
 		return nil, err
 	}
@@ -49,7 +65,7 @@ func (fs *Embed) OpenFile(filename string, flag int, perm os.FileMode) (billy.Fi
 		return nil, billy.ErrReadOnly
 	}
 
-	f, err := fs.underlying.Open(filename)
+	f, err := fs.underlying.Open(fs.path(filename))
 	if err != nil {
 		return nil, err
 	}
@@ -63,7 +79,7 @@ func (fs *Embed) OpenFile(filename string, flag int, perm os.FileMode) (billy.Fi
 		return nil, fmt.Errorf("cannot open directory: %s", filename)
 	}
 
-	data, err := fs.underlying.ReadFile(filename)
+	data, err := fs.underlying.ReadFile(fs.path(filename))
 	if err != nil {
 		return nil, err
 	}
@@ -74,11 +90,19 @@ func (fs *Embed) OpenFile(filename string, flag int, perm os.FileMode) (billy.Fi
 }
 
 func (fs *Embed) Join(elem ...string) string {
-	return filepath.Join(elem...)
+	// Function adapted from Go's filepath.Join for unix:
+	// https://github.com/golang/go/blob/1ed85ee228023d766b37db056311929c00091c9f/src/path/filepath/path_unix.go#L45
+	for i, el := range elem {
+		if el != "" {
+			// reuses filepath.Clean, as it is OS agnostic.
+			return filepath.Clean(strings.Join(elem[i:], "/"))
+		}
+	}
+	return ""
 }
 
 func (fs *Embed) ReadDir(path string) ([]os.FileInfo, error) {
-	e, err := fs.underlying.ReadDir(path)
+	e, err := fs.underlying.ReadDir(fs.path(path))
 	if err != nil {
 		return nil, err
 	}
@@ -94,6 +118,34 @@ func (fs *Embed) ReadDir(path string) ([]os.FileInfo, error) {
 	return entries, nil
 }
 
+// Lstat is not supported.
+//
+// Calls will always return billy.ErrNotSupported.
+func (fs *Embed) Lstat(_ string) (os.FileInfo, error) {
+	return nil, billy.ErrNotSupported
+}
+
+// Readlink is not supported.
+//
+// Calls will always return billy.ErrNotSupported.
+func (fs *Embed) Readlink(_ string) (string, error) {
+	return "", billy.ErrNotSupported
+}
+
+// TempFile is not supported.
+//
+// Calls will always return billy.ErrNotSupported.
+func (fs *Embed) TempFile(_, _ string) (billy.File, error) {
+	return nil, billy.ErrNotSupported
+}
+
+// Symlink is not supported.
+//
+// Calls will always return billy.ErrReadOnly.
+func (fs *Embed) Symlink(_, _ string) error {
+	return billy.ErrReadOnly
+}
+
 // Create is not supported.
 //
 // Calls will always return billy.ErrReadOnly.

internal/embedfs/embed_test.go

@@ -321,3 +321,41 @@ func TestFileSeek(t *testing.T) {
 		})
 	}
 }
+
+func TestJoin(t *testing.T) {
+	tests := []struct {
+		name string
+		path []string
+		want string
+	}{
+		{
+			name: "no leading slash",
+			path: []string{"data", "foo/bar"},
+			want: "data/foo/bar",
+		},
+		{
+			name: "w/ leading slash",
+			path: []string{"/data", "foo/bar"},
+			want: "/data/foo/bar",
+		},
+		{
+			name: "dot dot",
+			path: []string{"/data", "../bar"},
+			want: "/bar",
+		},
+		{
+			name: "dot",
+			path: []string{"/data", "./bar"},
+			want: "/data/bar",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			fs := New(&empty, "")
+
+			got := fs.Join(tc.path...)
+			assert.Equal(t, got, tc.want)
+		})
+	}
+}