Optimize map { ... }.compact calls (#15513)

* Optimize map { ... }.compact

using Enumerable#filter_map, supported since Ruby 2.7

* Add poyfill for Enumerable#filter_map

app/services/activitypub/fetch_featured_collection_service.rb

@@ -24,8 +24,7 @@ class ActivityPub::FetchFeaturedCollectionService < BaseService
   def process_items(items)
     status_ids = items.map { |item| value_or_id(item) }
                       .reject { |uri| ActivityPub::TagManager.instance.local_uri?(uri) }
-                      .map { |uri| ActivityPub::FetchRemoteStatusService.new.call(uri) }
-                      .compact
+                      .filter_map { |uri| ActivityPub::FetchRemoteStatusService.new.call(uri) }
                       .select { |status| status.account_id == @account.id }
                       .map(&:id)
 

app/services/activitypub/process_collection_service.rb

@@ -37,7 +37,7 @@ class ActivityPub::ProcessCollectionService < BaseService
   end
 
   def process_items(items)
-    items.reverse_each.map { |item| process_item(item) }.compact
+    items.reverse_each.filter_map { |item| process_item(item) }
   end
 
   def supported_context?

app/services/activitypub/process_poll_service.rb

@@ -30,7 +30,7 @@ class ActivityPub::ProcessPollService < BaseService
 
     voters_count = @json['votersCount']
 
-    latest_options = items.map { |item| item['name'].presence || item['content'] }.compact
+    latest_options = items.filter_map { |item| item['name'].presence || item['content'] }
 
     # If for some reasons the options were changed, it invalidates all previous
     # votes, so we need to remove them

app/services/activitypub/synchronize_followers_service.rb

@@ -14,7 +14,7 @@ class ActivityPub::SynchronizeFollowersService < BaseService
     # should never happen in practice, since in almost all cases we keep an
     # Account record, and should we not do that, we should have sent a Delete.
     # In any case there is not much we can do if that occurs.
-    @expected_followers = items.map { |uri| ActivityPub::TagManager.instance.uri_to_resource(uri, Account) }.compact
+    @expected_followers = items.filter_map { |uri| ActivityPub::TagManager.instance.uri_to_resource(uri, Account) }
 
     remove_unexpected_local_followers!
     handle_unexpected_outgoing_follows!

app/services/fetch_link_card_service.rb

@@ -67,7 +67,7 @@ class FetchLinkCardService < BaseService
     else
       html  = Nokogiri::HTML(@status.text)
       links = html.css('a')
-      urls  = links.map { |a| Addressable::URI.parse(a['href']) unless skip_link?(a) }.compact.map(&:normalize).compact
+      urls  = links.filter_map { |a| Addressable::URI.parse(a['href']) unless skip_link?(a) }.filter_map(&:normalize)
     end
 
     urls.reject { |uri| bad_url?(uri) }.first

app/services/import_service.rb

@@ -107,12 +107,12 @@ class ImportService < BaseService
       end
     end
 
-    statuses = items.map do |uri|
+    statuses = items.filter_map do |uri|
       status = ActivityPub::TagManager.instance.uri_to_resource(uri, Status)
       next if status.nil? && ActivityPub::TagManager.instance.local_uri?(uri)
 
       status || ActivityPub::FetchRemoteStatusService.new.call(uri)
-    end.compact
+    end
 
     account_ids         = statuses.map(&:account_id)
     preloaded_relations = relations_map_for_account(@account, account_ids)