added the ability to add string or bytes to a box

box.go

@@ -38,6 +38,7 @@ func NewBox(path string) Box {
 	return Box{
 		Path:       path,
 		callingDir: cd,
+		data:       map[string][]byte{},
 	}
 }
 
@@ -50,6 +51,14 @@ type Box struct {
 	directories map[string]bool
 }
 
+func (b Box) AddString(path string, t string) {
+	b.AddBytes(path, []byte(t))
+}
+
+func (b Box) AddBytes(path string, t []byte) {
+	b.data[path] = t
+}
+
 // String of the file asked for or an empty string.
 func (b Box) String(name string) string {
 	return string(b.Bytes(name))
@@ -102,6 +111,9 @@ func (b Box) decompress(bb []byte) []byte {
 }
 
 func (b Box) find(name string) (File, error) {
+	if bb, ok := b.data[name]; ok {
+		return newVirtualFile(name, bb), nil
+	}
 	if b.directories == nil {
 		b.indexDirectories()
 	}
@@ -183,7 +195,7 @@ func (b Box) Open(name string) (http.File, error) {
 func (b Box) List() []string {
 	var keys []string
 
-	if b.data == nil {
+	if b.data == nil || len(b.data) == 0 {
 		b.Walk(func(path string, info File) error {
 			finfo, _ := info.FileInfo()
 			if !finfo.IsDir() {

box_test.go

@@ -122,4 +122,30 @@ func Test_Virtual_Directory_Not_Found(t *testing.T) {
 	r.NoError(err)
 	_, err = virtualBox.find("does-not-exist")
 	r.Error(err)
-}
+}
+
+func Test_AddString(t *testing.T) {
+	r := require.New(t)
+
+	_, err := virtualBox.find("string")
+	r.Error(err)
+
+	virtualBox.AddString("string", "hello")
+
+	_, err = virtualBox.find("string")
+	r.NoError(err)
+	r.Equal("hello", virtualBox.String("string"))
+}
+
+func Test_AddBytes(t *testing.T) {
+	r := require.New(t)
+
+	_, err := virtualBox.find("bytes")
+	r.Error(err)
+
+	virtualBox.AddBytes("bytes", []byte("hello"))
+
+	_, err = virtualBox.find("bytes")
+	r.NoError(err)
+	r.Equal("hello", virtualBox.String("bytes"))
+}