Hypermodel `after_commit` handler is dropping errors instead of raising

Hypermodel の after_commit メソッドから始めて SendPacket.run の結果を調べ、その後 InternalPolicy#send_message を読んで promise のエラーがどのように処理されるかを理解します。after-commit broadcast からのエラーが破棄されずに raise され、server-not-running rescue は変更されない状態になれば完了です。

in the after_commit method of hypermodel, the SendPacket operation is run which will return a promise, but it is not checked for an error state.

def self.after_commit(operation, model)
  # Calling public_columns_hash once insures all policies are loaded
  # before the first broadcast.
  @public_columns_hash ||= ActiveRecord::Base.public_columns_hash
  Hyperstack::InternalPolicy.regulate_broadcast(model) do |data|
    puts "Broadcast aftercommit hook: #{data}" if Hyperstack::Connection.show_diagnostics

    if !Hyperstack.on_server? && Hyperstack::Connection.root_path
      send_to_server(operation, data, model.__synchromesh_update_time) rescue nil # fails if server no longer running so ignore
    else
      SendPacket.run(data, operation: operation, updated_at: model.__synchromesh_update_time)
    end
  end
rescue ActiveRecord::StatementInvalid => e
  raise e unless e.message == "Could not find table 'hyperstack_connections'"
end unless RUBY_ENGINE == 'opal'

The line containing SendPacket should be

SendPacket.run(data, operation: operation, updated_at: model.__synchromesh_update_time).tap { |p| raise p.error if p.error }

The easiest way to patch this is by adding this:

module Hyperstack
  class InternalPolicy
    alias original_send_message send_message
    def send_message(*args, &block)
      original_send_message(*args, &block).tap { |p| raise p.error if p.is_a?(Promise) && p.error }
    end  
  end
end

This will catch the error with the smallest patch. Note the patch needs to check if its a promise, but the actual fix does not.