add a test case

weed/server/filer_ui/breadcrumb_test.go

@@ -14,6 +14,18 @@ func TestToBreadcrumb(t *testing.T) {
 		args       args
 		wantCrumbs []Breadcrumb
 	}{
+		{
+			name: "empty",
+			args: args{
+				fullpath: "",
+			},
+			wantCrumbs: []Breadcrumb{
+				{
+					Name: "/",
+					Link: "/",
+				},
+			},
+		},
 		{
 			name: "test1",
 			args: args{