operations: fix lsjson --stat on root directories of bucket based backends

fs/operations/lsjson.go

@@ -264,6 +264,21 @@ func StatJSON(ctx context.Context, fsrc fs.Fs, remote string, opt *ListJSONOpt)
 	if err != nil {
 		return nil, err
 	}
+
+	// Root is always a directory. When we have a NewDirEntry
+	// primitive we need to call it, but for now this will do.
+	if remote == "" {
+		if !lj.dirs {
+			return nil, nil
+		}
+		// Check the root directory exists
+		_, err := fsrc.List(ctx, "")
+		if err != nil {
+			return nil, err
+		}
+		return lj.entry(ctx, fs.NewDir("", time.Now()))
+	}
+
 	// Could be a file or a directory here
 	if lj.files {
 		// NewObject can return the sentinel errors ErrorObjectNotFound or ErrorIsDir
@@ -288,14 +303,6 @@ func StatJSON(ctx context.Context, fsrc fs.Fs, remote string, opt *ListJSONOpt)
 		}
 	}
 	// Must be a directory here
-	if remote == "" {
-		// Check the root directory exists
-		_, err := fsrc.List(ctx, "")
-		if err != nil {
-			return nil, err
-		}
-		return lj.entry(ctx, fs.NewDir("", time.Now()))
-	}
 	parent := path.Dir(remote)
 	if parent == "." || parent == "/" {
 		parent = ""

fs/operations/lsjson_test.go

@@ -133,7 +133,7 @@ func TestListJSON(t *testing.T) {
 				IsDir:   false,
 			}},
 		}, {
-			name: "NoModTime",
+			name: "NoMimeType",
 			opt: operations.ListJSONOpt{
 				FilesOnly:  true,
 				NoMimeType: true,
@@ -254,6 +254,24 @@ func TestStatJSON(t *testing.T) {
 				Name:  "",
 				IsDir: true,
 			},
+		}, {
+			name:   "RootFilesOnly",
+			remote: "",
+			opt: operations.ListJSONOpt{
+				FilesOnly: true,
+			},
+			want: nil,
+		}, {
+			name:   "RootDirsOnly",
+			remote: "",
+			opt: operations.ListJSONOpt{
+				DirsOnly: true,
+			},
+			want: &operations.ListJSONItem{
+				Path:  "",
+				Name:  "",
+				IsDir: true,
+			},
 		}, {
 			name:   "Dir",
 			remote: "sub",