Poor man's fixtures for hanami

fixtures.rb

#
# A quick and dirty fixture implementation for use with Hanami, RSpec and PostgreSQL.
# Fixtures will be loaded when the suite starts and will be reset using transactions
# to the same state after each test case.
#
# Supports associations like so (author has many books):
#
# # authors.yml
# rowling:
#   name: J.K. Rowling
#
# # books.yml
# hp1:
#   name: Harry Potter and the Philosopher's stone
#   author: rowling
#

# put this in spec/support/fixtures.rb
# put your fixtures in spec/fixtures

ENV['HANAMI_ENV'] = 'test'

require 'yaml'

fixtures_path = 'spec/fixtures'

@connection = Hanami::Model.configuration.connection
@fixture_landscape = {}
@execution_plan = {}

def foreign_key_columns(table_name)
  @connection[table_name.to_sym].columns.select do |column|
    column != :id && column.to_s.end_with?('id')
  end
end

def add_timestamps_if_necessary(attributes)
  ['created_at', 'updated_at'].each do |timestamp_attribute|
    if attributes[timestamp_attribute].nil?
      attributes[timestamp_attribute] = DateTime.now
    end
  end

  attributes
end

def record_name_to_id(record_name)
  record_name.hash
end

def lookup_foreign_keys(table_name, attributes)
  foreign_key_columns = foreign_key_columns(table_name)

  foreign_key_columns.each do |foreign_key_column|
    foreign_record_name = attributes.delete(foreign_key_column.to_s[0..-4])
    attributes[foreign_key_column.to_s] = record_name_to_id(foreign_record_name)
  end

  attributes
end

def add_id_column(record_name, attributes)
  attributes['id'] = record_name_to_id(record_name)
  attributes
end

def enrich_attributes(table_name, record_name, attributes)
  add_id_column(record_name, add_timestamps_if_necessary(lookup_foreign_keys(table_name, attributes)))
end

def process_records(table_name, records)
  records.each do |record_name, attributes|
    @execution_plan[table_name] ||= []
    @execution_plan[table_name] << enrich_attributes(table_name, record_name, attributes)
  end
end

def process_fixture(fixture_path)
  fixture_hash = YAML.load(File.read(fixture_path))
  table_name = File.basename(fixture_path, '.*')
  @fixture_landscape.merge!({table_name => fixture_hash})
  process_records(table_name, fixture_hash)
end

def insert_records
  @execution_plan.each do |table_name, records|
    records.each do |attributes|
      puts "INSERT #{table_name}: #{attributes}"
      @connection[table_name.to_sym].insert(attributes)
    end
  end
end

@connection.transaction do
  puts "SET CONSTRAINTS ALL DEFERRED;"
  @connection.run("SET CONSTRAINTS ALL DEFERRED;")

  Dir.glob(fixtures_path + '/**/*.yml').each do |fixture_path|
    process_fixture(fixture_path)
  end
  insert_records
end

spec_helper.rb

# Add this stuff to your spec_helper.rb

config.around(:each) do |example|
  Hanami::Model.configuration.connection.transaction(savepoint: true) do
    example.run
    raise Sequel::Rollback
  end
end