Add `Status::MEDIA_ATTACHMENTS_LIMIT` configuration constant (#30433)

app/lib/activitypub/activity/create.rb

@@ -110,7 +110,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   def process_status_params
     @status_parser = ActivityPub::Parser::StatusParser.new(@json, followers_collection: @account.followers_url, object: @object)
 
-    attachment_ids = process_attachments.take(4).map(&:id)
+    attachment_ids = process_attachments.take(Status::MEDIA_ATTACHMENTS_LIMIT).map(&:id)
 
     @params = {
       uri: @status_parser.uri,
@@ -260,7 +260,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     as_array(@object['attachment']).each do |attachment|
       media_attachment_parser = ActivityPub::Parser::MediaAttachmentParser.new(attachment)
 
-      next if media_attachment_parser.remote_url.blank? || media_attachments.size >= 4
+      next if media_attachment_parser.remote_url.blank? || media_attachments.size >= Status::MEDIA_ATTACHMENTS_LIMIT
 
       begin
         media_attachment = MediaAttachment.create(

app/models/status.rb

@@ -39,6 +39,8 @@ class Status < ApplicationRecord
   include Status::SnapshotConcern
   include Status::ThreadingConcern
 
+  MEDIA_ATTACHMENTS_LIMIT = 4
+
   rate_limit by: :account, family: :statuses
 
   self.discard_column = :deleted_at

app/serializers/rest/instance_serializer.rb

@@ -59,7 +59,7 @@ class REST::InstanceSerializer < ActiveModel::Serializer
 
       statuses: {
         max_characters: StatusLengthValidator::MAX_CHARS,
-        max_media_attachments: 4,
+        max_media_attachments: Status::MEDIA_ATTACHMENTS_LIMIT,
         characters_reserved_per_url: StatusLengthValidator::URL_PLACEHOLDER_CHARS,
       },
 

app/serializers/rest/v1/instance_serializer.rb

@@ -64,7 +64,7 @@ class REST::V1::InstanceSerializer < ActiveModel::Serializer
 
       statuses: {
         max_characters: StatusLengthValidator::MAX_CHARS,
-        max_media_attachments: 4,
+        max_media_attachments: Status::MEDIA_ATTACHMENTS_LIMIT,
         characters_reserved_per_url: StatusLengthValidator::URL_PLACEHOLDER_CHARS,
       },
 

app/services/activitypub/process_status_update_service.rb

@@ -73,7 +73,7 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
     as_array(@json['attachment']).each do |attachment|
       media_attachment_parser = ActivityPub::Parser::MediaAttachmentParser.new(attachment)
 
-      next if media_attachment_parser.remote_url.blank? || @next_media_attachments.size > 4
+      next if media_attachment_parser.remote_url.blank? || @next_media_attachments.size > Status::MEDIA_ATTACHMENTS_LIMIT
 
       begin
         media_attachment   = previous_media_attachments.find { |previous_media_attachment| previous_media_attachment.remote_url == media_attachment_parser.remote_url }

app/services/post_status_service.rb

@@ -130,9 +130,9 @@ class PostStatusService < BaseService
       return
     end
 
-    raise Mastodon::ValidationError, I18n.t('media_attachments.validations.too_many') if @options[:media_ids].size > 4 || @options[:poll].present?
+    raise Mastodon::ValidationError, I18n.t('media_attachments.validations.too_many') if @options[:media_ids].size > Status::MEDIA_ATTACHMENTS_LIMIT || @options[:poll].present?
 
-    @media = @account.media_attachments.where(status_id: nil).where(id: @options[:media_ids].take(4).map(&:to_i))
+    @media = @account.media_attachments.where(status_id: nil).where(id: @options[:media_ids].take(Status::MEDIA_ATTACHMENTS_LIMIT).map(&:to_i))
 
     raise Mastodon::ValidationError, I18n.t('media_attachments.validations.images_and_video') if @media.size > 1 && @media.find(&:audio_or_video?)
     raise Mastodon::ValidationError, I18n.t('media_attachments.validations.not_ready') if @media.any?(&:not_processed?)

app/services/update_status_service.rb

@@ -69,9 +69,9 @@ class UpdateStatusService < BaseService
   def validate_media!
     return [] if @options[:media_ids].blank? || !@options[:media_ids].is_a?(Enumerable)
 
-    raise Mastodon::ValidationError, I18n.t('media_attachments.validations.too_many') if @options[:media_ids].size > 4 || @options[:poll].present?
+    raise Mastodon::ValidationError, I18n.t('media_attachments.validations.too_many') if @options[:media_ids].size > Status::MEDIA_ATTACHMENTS_LIMIT || @options[:poll].present?
 
-    media_attachments = @status.account.media_attachments.where(status_id: [nil, @status.id]).where(scheduled_status_id: nil).where(id: @options[:media_ids].take(4).map(&:to_i)).to_a
+    media_attachments = @status.account.media_attachments.where(status_id: [nil, @status.id]).where(scheduled_status_id: nil).where(id: @options[:media_ids].take(Status::MEDIA_ATTACHMENTS_LIMIT).map(&:to_i)).to_a
 
     raise Mastodon::ValidationError, I18n.t('media_attachments.validations.images_and_video') if media_attachments.size > 1 && media_attachments.find(&:audio_or_video?)
     raise Mastodon::ValidationError, I18n.t('media_attachments.validations.not_ready') if media_attachments.any?(&:not_processed?)

spec/requests/api/v2/instance_spec.rb

@@ -45,7 +45,7 @@ describe 'Instances' do
           ),
           statuses: include(
             max_characters: StatusLengthValidator::MAX_CHARS,
-            max_media_attachments: 4 # TODO, move to constant somewhere
+            max_media_attachments: Status::MEDIA_ATTACHMENTS_LIMIT
           ),
           polls: include(
             max_options: PollValidator::MAX_OPTIONS

spec/services/post_status_service_spec.rb

@@ -228,14 +228,15 @@ RSpec.describe PostStatusService do
     expect(media.reload.status).to be_nil
   end
 
-  it 'does not allow attaching more than 4 files' do
+  it 'does not allow attaching more files than configured limit' do
+    stub_const('Status::MEDIA_ATTACHMENTS_LIMIT', 1)
     account = Fabricate(:account)
 
     expect do
       subject.call(
         account,
         text: 'test status update',
-        media_ids: Array.new(5) { Fabricate(:media_attachment, account: account) }.map(&:id)
+        media_ids: Array.new(2) { Fabricate(:media_attachment, account: account) }.map(&:id)
       )
     end.to raise_error(
       Mastodon::ValidationError,