Refactor unnest logic

packages/runtime/native/Emotion.ml

@@ -288,10 +288,11 @@ let resolve_selectors rules =
  when starts_with_at current_selector ->
  Right [| Rule.Selector (current_selector, selector_rules) |]
  | Rule.Selector (current_selector, selector_rules) ->
- let is_first_level = prefix != "" in
  (* we derive the new prefix based on the current_selector and the previous "prefix" (aka the prefix added by the parent selector) *)
  let new_prefix =
- if is_first_level then
+ match prefix with
+ | None -> current_selector
+ | Some prefix ->
  (* child starts with &, join them without space *)
  if starts_with_ampersand current_selector then
  prefix ^ remove_first_ampersand current_selector
@@ -305,22 +306,22 @@ let resolve_selectors rules =
  else if starts_with_dot current_selector then
  prefix ^ " " ^ current_selector
  else prefix ^ " " ^ current_selector
- else prefix ^ current_selector
  in
  let selector_rules = split_multiple_selectors selector_rules in
  let selectors, rest_of_declarations =
- unnest_selectors ~prefix:new_prefix selector_rules
+ unnest_selectors ~prefix:(Some new_prefix) selector_rules
  in
  let new_selector = Rule.Selector (new_prefix, selectors) in
- Right
- (Array.append [| new_selector |] (Array.flatten rest_of_declarations))
+ Right (Array.append [| new_selector |] rest_of_declarations)
  | _ as rule -> Left rule)
+ |> fun (selectors, declarations) -> selectors, Array.flatten declarations
  in
 
  let rules = move_media_at_top rules in
  let rules = split_multiple_selectors rules in
- let declarations, selectors = unnest_selectors ~prefix:"" rules in
- Array.append declarations (Array.flatten selectors)
+ (* The base case for unnesting is without any prefix *)
+ let declarations, selectors = unnest_selectors ~prefix:None rules in
+ Array.append declarations selectors
 
 let render_keyframes animationName keyframes =
  let definition =