Set correct content-type for ActivityPub JSON (#4592)

app/controllers/accounts_controller.rb

@@ -17,7 +17,7 @@ class AccountsController < ApplicationController
       end
 
       format.json do
-        render json: @account, serializer: ActivityPub::ActorSerializer, adapter: ActivityPub::Adapter
+        render json: @account, serializer: ActivityPub::ActorSerializer, adapter: ActivityPub::Adapter, content_type: 'application/activity+json'
       end
     end
   end

app/controllers/activitypub/outboxes_controller.rb

@@ -7,7 +7,7 @@ class ActivityPub::OutboxesController < Api::BaseController
     @statuses = @account.statuses.permitted_for(@account, current_account).paginate_by_max_id(20, params[:max_id], params[:since_id])
     @statuses = cache_collection(@statuses, Status)
 
-    render json: outbox_presenter, serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter
+    render json: outbox_presenter, serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter, content_type: 'application/activity+json'
   end
 
   private

app/controllers/follower_accounts_controller.rb

@@ -10,7 +10,7 @@ class FollowerAccountsController < ApplicationController
       format.html
 
       format.json do
-        render json: collection_presenter, serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter
+        render json: collection_presenter, serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter, content_type: 'application/activity+json'
       end
     end
   end

app/controllers/following_accounts_controller.rb

@@ -10,7 +10,7 @@ class FollowingAccountsController < ApplicationController
       format.html
 
       format.json do
-        render json: collection_presenter, serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter
+        render json: collection_presenter, serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter, content_type: 'application/activity+json'
       end
     end
   end

app/controllers/statuses_controller.rb

@@ -20,13 +20,13 @@ class StatusesController < ApplicationController
       end
 
       format.json do
-        render json: @status, serializer: ActivityPub::NoteSerializer, adapter: ActivityPub::Adapter
+        render json: @status, serializer: ActivityPub::NoteSerializer, adapter: ActivityPub::Adapter, content_type: 'application/activity+json'
       end
     end
   end
 
   def activity
-    render json: @status, serializer: ActivityPub::ActivitySerializer, adapter: ActivityPub::Adapter
+    render json: @status, serializer: ActivityPub::ActivitySerializer, adapter: ActivityPub::Adapter, content_type: 'application/activity+json'
   end
 
   private

app/controllers/tags_controller.rb

@@ -12,7 +12,7 @@ class TagsController < ApplicationController
       format.html
 
       format.json do
-        render json: collection_presenter, serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter
+        render json: collection_presenter, serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter, content_type: 'application/activity+json'
       end
     end
   end

config/initializers/mime_types.rb

 # Be sure to restart your server when you modify this file.
 
-Mime::Type.register 'application/json', :json, %w(text/x-json application/jsonrequest application/jrd+json application/activity+json)
+Mime::Type.register 'application/json', :json, %w(text/x-json application/jsonrequest application/jrd+json application/activity+json application/ld+json)
 Mime::Type.register 'text/xml',         :xml,  %w(application/xml application/atom+xml application/xrd+xml)

spec/controllers/accounts_controller_spec.rb

@@ -48,6 +48,10 @@ RSpec.describe AccountsController, type: :controller do
       it 'returns http success with Activity Streams 2.0' do
         expect(response).to have_http_status(:success)
       end
+
+      it 'returns application/activity+json' do
+        expect(response.content_type).to eq 'application/activity+json'
+      end
     end
 
     context 'html' do

spec/controllers/activitypub/outboxes_controller_spec.rb

@@ -15,5 +15,9 @@ RSpec.describe ActivityPub::OutboxesController, type: :controller do
     it 'returns http success' do
       expect(response).to have_http_status(:success)
     end
+
+    it 'returns application/activity+json' do
+      expect(response.content_type).to eq 'application/activity+json'
+    end
   end
 end