hanami-model integration to ruby project

Question

structure of my application:

.
├── config
│   ├── boot.rb
│   └── environment.rb
├── Gemfile
├── Gemfile.lock
├── lib
│   ├── entities
│   │   └── account.rb
│   └── repositories
│       └── account_repository.rb
└── README.md

Gemfile:

source 'https://rubygems.org'

gem 'pg', '~> 1.1'
gem 'dotenv'
gem 'byebug'
gem 'hanami-model'

config/environment.rb:

require 'bundler/setup'
require 'hanami/model'
require 'dotenv/load'

class App
  class << self
    def boot
      Mutex.new.synchronize do
        Hanami::Model.configure do
          adapter :sql, ENV['DATABASE_URL']
        end.load!
      end
    end
  end
end

config/boot.rb:

require_relative './environment'
App.boot

lib/entities/account.rb:

require 'hanami/model'
require_relative '../repositories/account_repository'

class Account < Hanami::Entity
end

lib/repositories/account_repository.rb:

require 'hanami/model'
require_relative '../entities/account'

class AccountRepository < Hanami::Repository
   self.relation = :accounts
end

in the console, I run the following code, and I get an error:

irb -I .
irb(main):001:0> require 'config/boot'
=> true
irb(main):002:0> require 'lib/repositories/account_repository'
=> true
irb(main):003:0> rep = AccountRepository.new
Traceback (most recent call last):
        6: from /home/mvalitov/.asdf/installs/ruby/2.5.1/bin/irb:11:in `<main>'
        5: from (irb):3
        4: from (irb):3:in `new'
        3: from /home/mvalitov/.asdf/installs/ruby/2.5.1/lib/ruby/gems/2.5.0/gems/hanami-model-1.3.2/lib/hanami/repository.rb:420:in `initialize'
        2: from /home/mvalitov/.asdf/installs/ruby/2.5.1/lib/ruby/gems/2.5.0/gems/rom-repository-1.4.0/lib/rom/repository/root.rb:62:in `initialize'
        1: from /home/mvalitov/.asdf/installs/ruby/2.5.1/lib/ruby/gems/2.5.0/gems/rom-3.3.3/lib/rom/registry.rb:30:in `fetch'
ArgumentError (key cannot be nil)

what am I doing wrong? if you put all the entity code and repositories in one file, the code runs without errors.

Answer 1

The issue is in order of load.

Here is a note about strict order in the documentation:

When using a sql adapter, you must require hanami/model/sql before Hanami::Model.load! is called so the relations are loaded correctly.

Source: https://github.com/hanami/model#mapping

Hence, for your case, need to run App.boot after all declarations.

In details:

If you put all your code into one file you will see differences:

# run.rb
require 'bundler/setup'
require 'hanami/model'
require 'dotenv/load'
class App
  class << self
    def boot
      Mutex.new.synchronize do
        Hanami::Model.configure do
          adapter :sql, 'postgresql://postgres:12345@localhost:5432/mame-challenge_development'
          path '/home/mifrill/Documents/source/hamani-bug'
        end.load!
      end
    end
  end
end
App.boot
class AccountRepository < Hanami::Repository
  self.relation = :accounts
end
class Account < Hanami::Entity
end
AccountRepository.new

ruby run.rb

gems/rom-3.3.3/lib/rom/registry.rb:30:in `fetch': key cannot be nil (ArgumentError)

Move App.boot after Repository and Entity definitions, like this:

require 'bundler/setup'
require 'hanami/model'
require 'dotenv/load'
class App
  class << self
    def boot
      Mutex.new.synchronize do
        Hanami::Model.configure do
          adapter :sql, 'postgresql://postgres:12345@localhost:5432/mame-challenge_development'
          path '/home/mifrill/Documents/source/hamani-bug'
        end.load!
      end
    end
  end
end
class AccountRepository < Hanami::Repository
  self.relation = :accounts
end
class Account < Hanami::Entity
end
App.boot
AccountRepository.new

ruby run.rb

{:accounts=>#<ROM::Relation[Accounts] name=accounts dataset=#<Sequel::Postgres::Dataset: "SELECT * FROM \"accounts\"">>

So, try to require Repository file before load! to solve:

config/boot.rb:

require_relative './environment'
require_relative '../lib/repositories/account_repository'
App.boot

irb -I .
require 'config/boot'
rep = AccountRepository.new
...
{:accounts=>#<ROM::Relation[Accounts] name=accounts dataset=#<Sequel::Postgres::Dataset: "SELECT * FROM \"accounts\"">>}

Answer 2

You are missing the "root" configuration/options (I don't know much as I don't use Hanami).

How did I find that?

Looking at the stacktrace:

• https://github.com/hanami/model/blob/master/lib/hanami/repository.rb#L420
• https://github.com/rom-rb/rom-repository/blob/master/lib/rom/repository/root.rb#L62
• https://github.com/rom-rb/rom/blob/master/core/lib/rom/registry.rb#L30
• Where the error is thrown: https://github.com/rom-rb/rom/blob/master/core/lib/rom/registry.rb#L71
• fetch has an alias :[]

(all links to latest because I'm lazy :) )