refactor api and fix bugs (#1088)

* fix weird double-embed issue

* fix users/current api if not logged in

* turbocharge the api

* fix docs

app/controllers/api/v2/users_controller.rb

@@ -3,6 +3,7 @@ module Api
   module V2
     class UsersController < RestfulController
       def current
+        raise Pundit::NotAuthorizedError if current_user.nil?
         @user = current_user
         authorize @user
         show # delegate to the normal show function

app/serializers/api/v2/application_serializer.rb

@@ -13,50 +13,49 @@ module Api
         @embeds ||= (scope[:embeds] || []).select { |e| self.class.embeddable.keys.include?(e) }
       end
 
-      # self.embeddable might look like this:
-      #   creator: { attr: :first_creator, serializer: UserSerializer }
-      #   contributors: { serializer: UserSerializer}
-      # This method will remove the :attr key if the underlying attribute name
-      # is different than the name provided in the final json output. All other keys
-      # in the hash will be passed to the ActiveModel::Serializer `attribute` method
-      # directly (e.g. serializer in the examples will be passed).
-      #
-      # This setup means if you passed this self.embeddable config and sent no
-      # ?embed= query param with your API request, you would get the regular attributes
-      # plus creator_id and contributor_ids. If you passed ?embed=creator,contributors
-      # then instead of an id and an array of ids, you would get a serialized user
-      # (the first_creator) and an array of serialized users (the contributors).
+      # Here's an example object that could be passed in self.embeddable: {
+      #   creator: {
+      #     serializer: UserSerializer,
+      #   },
+      #   collaborators: {
+      #     serializer: UserSerializer
+      #   },
+      #   topic: {},
+      #   synapses: {}
+      # }
+      # The key has to be in embeddable or it won't show in the response, and the serializer is
+      # only needed if the key doesn't match a serializer
       def self.embed_dat
         embeddable.each_pair do |key, opts|
-          attr = opts.delete(:attr) || key
-          if attr.to_s.pluralize == attr.to_s
-            attribute("#{attr.to_s.singularize}_ids".to_sym,
-                      opts.merge(unless: -> { embeds.include?(key) })) do
-              Pundit.policy_scope(scope[:current_user], object.send(attr))&.map(&:id) || []
+          is_plural = key.to_s.pluralize == key.to_s
+          id_key = key.to_s.singularize + (is_plural ? '_ids' : '_id')
+          serializer = opts.delete(:serializer) || "Api::V2::#{key.to_s.singularize.camelize}Serializer".constantize
+          if is_plural
+            attribute(id_key.to_sym, opts.merge(unless: -> { embeds.include?(key) })) do
+              Pundit.policy_scope(scope[:current_user], object.send(key))&.map(&:id) || []
             end
-            has_many(attr, opts.merge(if: -> { embeds.include?(key) })) do
-              list = Pundit.policy_scope(scope[:current_user], object.send(attr)) || []
-              child_serializer = "Api::V2::#{attr.to_s.singularize.camelize}Serializer".constantize
+            has_many(key, opts.merge(if: -> { embeds.include?(key) })) do
+              list = Pundit.policy_scope(scope[:current_user], object.send(key)) || []
               resource = ActiveModelSerializers::SerializableResource.new(
                 list,
-                each_serializer: child_serializer,
+                each_serializer: serializer,
                 scope: scope.merge(embeds: [])
               )
-              resource.as_json
+              # resource.as_json will return e.g. { users: [ ... ] } for collaborators
+              # since we can't get the :users key, convert to an array and use .first.second to get the needed values
+              resource&.as_json&.to_a&.first&.second
             end
           else
-            id_opts = opts.merge(key: "#{key}_id")
-            attribute("#{attr}_id".to_sym,
-                      id_opts.merge(unless: -> { embeds.include?(key) }))
-            attribute(key, opts.merge(if: -> { embeds.include?(key) })) do |serializer|
-              object = serializer.object.send(key)
-              child_serializer = "Api::V2::#{object.class.name}Serializer".constantize
+            attribute(id_key.to_sym, opts.merge(unless: -> { embeds.include?(key) }))
+            attribute(key, opts.merge(if: -> { embeds.include?(key) })) do |parent_serializer|
+              object = parent_serializer.object.send(key)
+              next nil if object.nil?
               resource = ActiveModelSerializers::SerializableResource.new(
                 object,
-                serializer: child_serializer,
+                serializer: serializer,
                 scope: scope.merge(embeds: [])
               )
-              resource.as_json
+              resource&.as_json&.to_a&.first&.second
             end
           end
         end

app/serializers/api/v2/map_serializer.rb

@@ -18,7 +18,7 @@ module Api
       def self.embeddable
         {
           user: {},
-          source: {},
+          source: { serializer: MapSerializer },
           topics: {},
           synapses: {},
           mappings: {},

app/serializers/api/v2/mapping_serializer.rb

@@ -14,7 +14,7 @@ module Api
       def self.embeddable
         {
           user: {},
-          updated_by: {},
+          updated_by: { serializer: UserSerializer },
           map: {}
         }
       end