Modify configuration structure. (#49)

fs/container.go

@@ -0,0 +1,24 @@
+package fs
+
+type ContainerFs struct {
+	s *storage
+}
+
+func NewContainerFs(fss map[string]Filesystem) (*ContainerFs, error) {
+	s := newStorage(SupportedFactories)
+	for p, fs := range fss {
+		if err := s.AddFS(fs, p); err != nil {
+			return nil, err
+		}
+	}
+
+	return &ContainerFs{s: s}, nil
+}
+
+func (fs *ContainerFs) Open(filename string) (File, error) {
+	return fs.s.Get(filename)
+}
+
+func (fs *ContainerFs) ReadDir(path string) (map[string]File, error) {
+	return fs.s.Children(path), nil
+}

fs/container_test.go

@@ -0,0 +1,28 @@
+package fs
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestContainer(t *testing.T) {
+	t.Parallel()
+
+	require := require.New(t)
+
+	fss := map[string]Filesystem{
+		"/test": &DummyFs{},
+	}
+
+	c, err := NewContainerFs(fss)
+	require.NoError(err)
+
+	f, err := c.Open("/test/dir/here")
+	require.NoError(err)
+	require.NotNil(f)
+
+	files, err := c.ReadDir("/")
+	require.NoError(err)
+	require.Len(files, 1)
+}

fs/storage.go

@@ -48,6 +48,22 @@ func (s *storage) Has(path string) bool {
 	return false
 }
 
+func (s *storage) AddFS(fs Filesystem, p string) error {
+	p = clean(p)
+	if s.Has(p) {
+		if dir, err := s.Get(p); err == nil {
+			if !dir.IsDir() {
+				return os.ErrExist
+			}
+		}
+
+		return nil
+	}
+
+	s.filesystems[p] = fs
+	return s.createParent(p, &Dir{})
+}
+
 func (s *storage) Add(f File, p string) error {
 	p = clean(p)
 	if s.Has(p) {
@@ -72,9 +88,7 @@ func (s *storage) Add(f File, p string) error {
 		s.files[p] = f
 	}
 
-	s.createParent(p, f)
-
-	return nil
+	return s.createParent(p, f)
 }
 
 func (s *storage) createParent(p string, f File) error {

fs/storage_test.go

@@ -102,6 +102,24 @@ func TestStorageWindowsPath(t *testing.T) {
 	require.Equal(&Dummy{}, file)
 }
 
+func TestStorageAddFs(t *testing.T) {
+	t.Parallel()
+
+	require := require.New(t)
+
+	s := newStorage(dummyFactories)
+
+	err := s.AddFS(&DummyFs{}, "/test")
+	require.NoError(err)
+
+	f, err := s.Get("/test/dir/here/file1.txt")
+	require.NoError(err)
+	require.NotNil(f)
+
+	err = s.AddFS(&DummyFs{}, "/test")
+	require.Error(err)
+}
+
 var _ Filesystem = &DummyFs{}
 
 type DummyFs struct {