Calling the create! method on a has_many association creates the corresponding node, but does not set up the relationship between the original node and the newly created one.

Note: I have only tested this with has_many associations, but it may apply to has_one as well.

Code example

class Author
  include ActiveGraph::Node
  
  property :name, String
  
  has_many :out, :books, model_class: 'Book', type: 'wrote'
end

class Book
  include ActiveGraph::Node
  
  property :title, String
  
  has_one :in, :author, model_class: 'Author', origin: :books
end

a = Author.create! name: 'Karl Marx'
b = a.books.create! title: 'Das Kapital'

puts a.books.length # 0
puts b.author # nil

I would expect that this would work more like ActiveRecord, and the (a)-[:wrote]->(b) relationship would be added to neo4j as well.

Workaround

b = a.books.create! title: 'Das Kaptial', author: a

works as expected.

Runtime information:

versions:

    activegraph (10.1.0)
    neo4j-ruby-driver (1.7.4)
    activesupport (6.1.3)

    ruby 3.0.0 (mri)

neo4j: 4.0.0