fstest/mockobject: add SetFs method so it can have a valid Fs() #3419

fstest/mockobject/mockobject.go

@@ -93,22 +93,37 @@ const (
 // SeekModes contains all valid SeekMode's
 var SeekModes = []SeekMode{SeekModeNone, SeekModeRegular, SeekModeRange}
 
-type contentMockObject struct {
+// ContentMockObject mocks an fs.Object and has content
+type ContentMockObject struct {
 	Object
 	content  []byte
 	seekMode SeekMode
+	f        fs.Fs
 }
 
 // WithContent returns a fs.Object with the given content.
-func (o Object) WithContent(content []byte, mode SeekMode) fs.Object {
-	return &contentMockObject{
+func (o Object) WithContent(content []byte, mode SeekMode) *ContentMockObject {
+	return &ContentMockObject{
 		Object:   o,
 		content:  content,
 		seekMode: mode,
 	}
 }
 
-func (o *contentMockObject) Open(ctx context.Context, options ...fs.OpenOption) (io.ReadCloser, error) {
+// SetFs sets the return value of the Fs() call
+func (o *ContentMockObject) SetFs(f fs.Fs) {
+	o.f = f
+}
+
+// Fs returns read only access to the Fs that this object is part of
+//
+// This is nil unless SetFs has been called
+func (o *ContentMockObject) Fs() fs.Info {
+	return o.f
+}
+
+// Open opens the file for read.  Call Close() on the returned io.ReadCloser
+func (o *ContentMockObject) Open(ctx context.Context, options ...fs.OpenOption) (io.ReadCloser, error) {
 	var offset, limit int64 = 0, -1
 	for _, option := range options {
 		switch x := option.(type) {
@@ -147,7 +162,9 @@ func (o *contentMockObject) Open(ctx context.Context, options ...fs.OpenOption)
 		return nil, errors.New(o.seekMode.String())
 	}
 }
-func (o *contentMockObject) Size() int64 {
+
+// Size returns the size of the file
+func (o *ContentMockObject) Size() int64 {
 	return int64(len(o.content))
 }