Use Zeitwerk for loading components

- Replace AutoRegistration with a new Loader that uses Zeitwerk
- Remove support for non-standard setups where dir structure doesn't
  match namespaces
- Deprecate `ROM::Setup#auto_registration` and move it to `rom/compat`

Refs #607

Gemfile

@@ -19,6 +19,8 @@ gem "rom-sql", github: "rom-rb/rom-sql", branch: "master"
 gem "dry-monitor", github: "dry-rb/dry-monitor", branch: "master"
 gem "dry-events", github: "dry-rb/dry-events", branch: "master"
 
+gem "zeitwerk", github: "fxn/zeitwerk", branch: "main"
+
 group :sql do
   gem "jdbc-postgres", platforms: :jruby
   gem "jdbc-sqlite3", platforms: :jruby

Rakefile

@@ -5,7 +5,15 @@ require "bundler/gem_tasks"
 require "rspec/core"
 require "rspec/core/rake_task"
 
-RSpec::Core::RakeTask.new(:spec)
+RSpec::Core::RakeTask.new("spec:all") do |t|
+  t.pattern = ["spec/unit/**/*_spec.rb", "spec/integration/**/*_spec.rb"]
+end
+
+RSpec::Core::RakeTask.new("spec:compat") do |t|
+  t.pattern = ["spec/compat/**/*_spec.rb"]
+end
+
+task "spec" => ["spec:all", "spec:compat"]
 
 task default: :spec
 
@@ -25,8 +33,10 @@ namespace :benchmark do
   end
 end
 
+# rubocop:disable Lint/SuppressedException
 begin
   require "yard-junk/rake"
   YardJunk::Rake.define_task(:text)
 rescue LoadError
 end
+# rubocop:enable Lint/SuppressedException

docsite/core/source/framework-setup.html.md

@@ -65,7 +65,7 @@ module Persistence
 end
 
 configuration = ROM::Configuration.new(:memory)
-configuration.auto_registration('root_dir/lib/persistence/')
+configuration.auto_register('root_dir/lib/persistence/')
 container = ROM.container(configuration)
 ```
 
@@ -92,7 +92,7 @@ Notice that the directory structure is different from our module structure. Sinc
 
 ```ruby
 configuration = ROM::Configuration.new(:memory)
-configuration.auto_registration('/path/to/lib', namespace: 'Persistence')
+configuration.auto_register('/path/to/lib', namespace: 'Persistence')
 container = ROM.container(configuration)
 ```
 
@@ -146,7 +146,7 @@ end
 Then, auto-registration can be achieved with
 
 ```ruby
-configuration.auto_registration('/path/to/lib', namespace: 'MyApp::Persistence')
+configuration.auto_register('/path/to/lib', namespace: 'MyApp::Persistence')
 ```
 
 #### Turning namespace off
@@ -162,7 +162,7 @@ end
 
 ```ruby
 configuration = ROM::Configuration.new(:memory)
-configuration.auto_registration('/path/to/lib', namespace: false)
+configuration.auto_register('/path/to/lib', namespace: false)
 container = ROM.container(configuration)
 ```
 

lib/rom/compat.rb

@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+require_relative "compat/setup"

lib/rom/setup/auto_registration.rb → lib/rom/compat/auto_registration.rb

@@ -6,9 +6,10 @@
 
 require "rom/types"
 require "rom/initializer"
-require "rom/setup/auto_registration_strategies/no_namespace"
-require "rom/setup/auto_registration_strategies/with_namespace"
-require "rom/setup/auto_registration_strategies/custom_namespace"
+
+require_relative "auto_registration_strategies/no_namespace"
+require_relative "auto_registration_strategies/with_namespace"
+require_relative "auto_registration_strategies/custom_namespace"
 
 module ROM
   # AutoRegistration is used to load component files automatically from the provided directory path

lib/rom/setup/auto_registration_strategies/custom_namespace.rb → lib/rom/compat/auto_registration_strategies/custom_namespace.rb

@@ -4,7 +4,8 @@
 
 require "rom/support/inflector"
 require "rom/types"
-require "rom/setup/auto_registration_strategies/base"
+
+require_relative "base"
 
 module ROM
   module AutoRegistrationStrategies

lib/rom/setup/auto_registration_strategies/no_namespace.rb → lib/rom/compat/auto_registration_strategies/no_namespace.rb

@@ -4,7 +4,7 @@
 
 require "rom/support/inflector"
 require "rom/types"
-require "rom/setup/auto_registration_strategies/base"
+require_relative "base"
 
 module ROM
   module AutoRegistrationStrategies

lib/rom/setup/auto_registration_strategies/with_namespace.rb → lib/rom/compat/auto_registration_strategies/with_namespace.rb

@@ -3,7 +3,7 @@
 require "pathname"
 
 require "rom/support/inflector"
-require "rom/setup/auto_registration_strategies/base"
+require_relative "base"
 
 module ROM
   module AutoRegistrationStrategies

lib/rom/compat/setup.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require_relative "auto_registration"
+
+module ROM
+  # Setup objects collect component classes during setup/finalization process
+  #
+  # @api public
+  class Setup
+    # Enable auto-registration for a given setup object
+    #
+    # @param [String, Pathname] directory The root path to components
+    # @param [Hash] options
+    # @option options [Boolean, String] :namespace Toggle root namespace
+    #                                              or provide a custom namespace name
+    #
+    # @return [Setup]
+    #
+    # @deprecated
+    #
+    # @api public
+    def auto_registration(directory, **options)
+      auto_registration = AutoRegistration.new(directory, inflector: inflector, **options)
+      auto_registration.relations.map { |r| register_relation(r) }
+      auto_registration.commands.map { |r| register_command(r) }
+      auto_registration.mappers.map { |r| register_mapper(r) }
+      self
+    end
+  end
+end

lib/rom/container.rb

@@ -74,7 +74,7 @@ module ROM
   #
   # @example multi-step setup with auto-registration
   #   config = ROM::Configuration.new(:sql, 'sqlite::memory')
-  #   config.auto_registration('./persistence', namespace: false)
+  #   config.auto_register('./persistence', namespace: false)
   #
   #   config.default.create_table :users do
   #     primary_key :id

lib/rom/loader.rb

@@ -0,0 +1,153 @@
+# frozen_string_literal: true
+
+require "pathname"
+require "zeitwerk"
+
+require "rom/support/inflector"
+
+require "rom/types"
+require "rom/initializer"
+require "rom/loader"
+
+module ROM
+  # AutoRegistration is used to load component files automatically from the provided directory path
+  #
+  # @api public
+  class Loader
+    extend Initializer
+
+    NamespaceType = Types::Strict::Bool | Types.Instance(Module)
+
+    PathnameType = Types.Constructor(Pathname, &Kernel.method(:Pathname))
+
+    InflectorType = Types.Interface(:camelize)
+
+    ComponentDirs = Types::Strict::Hash.constructor { |hash|
+      hash.map { |key, value| [key, value.to_s] }.to_h
+    }
+
+    DEFAULT_MAPPING = {
+      relations: "relations",
+      mappers: "mappers",
+      commands: "commands"
+    }.freeze
+
+    # @!attribute [r] directory
+    #   @return [Pathname] The root path
+    param :root_directory, type: PathnameType
+
+    # @!attribute [r] namespace
+    #   @return [Boolean,String]
+    #     The name of the top level namespace or true/false which
+    #     enables/disables default top level namespace inferred from the dir name
+    option :namespace, type: NamespaceType, default: -> { true }
+
+    # @!attribute [r] component_dirs
+    #   @return [Hash] component => dir-name map
+    option :component_dirs, type: ComponentDirs, default: -> { DEFAULT_MAPPING }
+
+    # @!attribute [r] inflector
+    #   @return [Dry::Inflector] String inflector
+    #   @api private
+    option :inflector, type: InflectorType, default: -> { Inflector }
+
+    # @!attribute [r] loaded_constants
+    #   @return [Dry::Inflector] String inflector
+    #   @api private
+    option :inflector, type: InflectorType, default: -> { Inflector }
+
+    option :loaded_constants, default: -> { {relations: [], commands: [], mappers: []} }
+
+    # Load components
+    #
+    # @api private
+    def constants(component_type)
+      unless @loaded
+        setup and backend.eager_load
+        @loaded = true
+      end
+
+      loaded_constants.fetch(component_type)
+    end
+
+    # Load relation files
+    #
+    # @api private
+    def relations
+      constants(__method__)
+    end
+
+    # Load command files
+    #
+    # @api private
+    def commands
+      constants(__method__)
+    end
+
+    # Load mapper files
+    #
+    # @api private
+    def mappers
+      constants(__method__)
+    end
+
+    private
+
+    # @api private
+    def backend
+      @backend ||= Zeitwerk::Loader.new
+    end
+
+    # @api private
+    # rubocop:disable Metrics/AbcSize
+    def setup
+      backend.inflector = inflector
+
+      case namespace
+      when true
+        backend.push_dir(root_directory.join("..").realpath)
+
+        component_dirs.each_value do |dir|
+          backend.collapse(root_directory.join(dir).join("**/*"))
+        end
+      when false
+        backend.push_dir(root_directory)
+      else
+        backend.push_dir(root_directory, namespace: namespace)
+      end
+
+      excluded_dirs.each do |dir|
+        backend.ignore(dir)
+      end
+
+      backend.on_load do |_, const, path|
+        if (type = path_to_component_type(path))
+          loaded_constants[type] << const
+        end
+      end
+
+      backend.setup
+    end
+    # rubocop:enable Metrics/AbcSize
+
+    # @api private
+    def path_to_component_type(path)
+      return unless File.file?(path)
+
+      component_dirs
+        .detect { |_, dir|
+          path.start_with?(root_directory.join(dir).to_s)
+        }
+        &.first
+    end
+
+    # @api private
+    def excluded_dirs
+      root_directory
+        .children
+        .select(&:directory?)
+        .reject { |dir| component_dirs.values.include?(dir.basename.to_s) }
+        .map { |name| root_directory.join(name) }
+    end
+  end
+end