YamlExporter

YamlExporter is a Ruby gem that provides YAML serialization and deserialization functionality for ActiveRecord models, with JSON schema generation for validation.

• Serialize ActiveRecord models to YAML
• Deserialize YAML back to ActiveRecord models
• Generate JSON schemas for model validation
• Support for nested associations (has_many and has_one)
• Automatic type inference based on database column types

Add this line to your application's Gemfile:

gem 'yaml_exporter'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install yaml_exporter

Include the YamlExporter module in your ActiveRecord model and define the YAML structure:

class Quiz < ApplicationRecord
  include YamlExporter

  yaml_structure do
    yaml_attribute :title, :quiz_type
    yaml_has_many :questions do
      yaml_attribute :text, :position, :question_type, :feedback
      yaml_has_many :answers do
        yaml_attribute :text, :is_correct, :impact
      end
    end
  end
end

To serialize a model instance to YAML:

quiz = Quiz.find(1)
yaml_string = quiz.yaml_export

To deserialize YAML back to a model instance:

quiz = Quiz.new
quiz.yaml_import(yaml_string)

To generate a JSON schema for validation:

schema = Quiz.yaml_schema

A runnable demo script shares the same in-memory schema and model definitions as the tests:

$ gem install sqlite3   # one-time prerequisite
$ bundle install
$ ruby script/demo_quiz.rb

Authoritative model definitions live in test/support/models.rb (with the matching test/support/schema.rb). Contract-test YAML lives in three multi-document files under test/fixtures/yaml/ (quiz.yml, training.yml, article.yml); tests pick a document by index via yaml_fixture('quiz', doc: 0) (see test/test_helper.rb).

The YamlExporter automatically infers types based on the database column types. JSON and JSONB columns are treated as objects in the generated schema.

Run bundle exec rake test. The file test/test_nested_association_regression_test.rb asserts the desired contract for Quiz → Question → Answer and Training → join (VM) when nested rows are only reordered in YAML. Those examples are currently expected to fail until update_collection matches rows by stable keys (for example id in YAML), not only by array index.

Bug reports and pull requests are welcome on GitHub at https://github.com/itadventurer/yaml_exporter.

The gem is available as open source under the terms of the MIT License.