Fix error if history file doesn't exist

io/fs/disk.go

@@ -203,7 +203,7 @@ func NewRootedDiskFilesystem(config RootedDiskConfig) (Filesystem, error) {
 
 	info, err := os.Stat(fs.root)
 	if err != nil {
-		return nil, err
+		return nil, os.ErrNotExist
 	}
 
 	if !info.IsDir() {
@@ -285,7 +285,7 @@ func (fs *diskFilesystem) Symlink(oldname, newname string) error {
 
 	info, err := os.Lstat(oldname)
 	if err != nil {
-		return err
+		return os.ErrNotExist
 	}
 
 	if info.Mode()&os.ModeSymlink != 0 {
@@ -494,7 +494,7 @@ func (fs *diskFilesystem) Stat(path string) (FileInfo, error) {
 
 	info, err := os.Lstat(path)
 	if err != nil {
-		return nil, err
+		return nil, os.ErrNotExist
 	}
 
 	dif.mode = info.Mode()
@@ -502,7 +502,7 @@ func (fs *diskFilesystem) Stat(path string) (FileInfo, error) {
 	if info.Mode()&os.ModeSymlink != 0 {
 		info, err = os.Stat(path)
 		if err != nil {
-			return nil, err
+			return nil, os.ErrNotExist
 		}
 	}
 

session/snapshot.go

@@ -2,6 +2,7 @@ package session
 
 import (
 	"bytes"
+	"errors"
 	"io"
 	"os"
 
@@ -39,8 +40,12 @@ func NewHistorySource(fs fs.Filesystem, path string) (SnapshotSource, error) {
 		path: path,
 	}
 
-	if _, err := s.fs.Stat(s.path); err == os.ErrNotExist {
+	if _, err := s.fs.Stat(s.path); err != nil {
-		return nil, nil
+		if errors.Is(err, os.ErrNotExist) {
+			return nil, nil
+		}
+
+		return nil, err
 	}
 
 	data, err := s.fs.ReadFile(s.path)

session/snapshot_test.go

@@ -0,0 +1,26 @@
+package session
+
+import (
+	"testing"
+
+	"github.com/datarhei/core/v16/io/fs"
+	"github.com/stretchr/testify/require"
+)
+
+func TestHistorySource(t *testing.T) {
+	memfs, err := fs.NewMemFilesystem(fs.MemConfig{})
+	require.NoError(t, err)
+
+	s, err := NewHistorySource(memfs, "/foobar.json")
+	require.NoError(t, err)
+	require.Nil(t, s)
+}
+
+func TestHistorySourceDisk(t *testing.T) {
+	diskfs, err := fs.NewDiskFilesystem(fs.DiskConfig{})
+	require.NoError(t, err)
+
+	s, err := NewHistorySource(diskfs, "./foobar.json")
+	require.NoError(t, err)
+	require.Nil(t, s)
+}