Use Zeitwerk for code loading (#225)

(Fix a Rubocop issue in the specs at the same time)

hanami-validations.gemspec

@@ -21,6 +21,7 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version = ">= 3.0"
 
   spec.add_dependency "dry-validation", ">= 1.10", "< 2"
+  spec.add_dependency "zeitwerk", "~> 2.6.0"
 
   spec.add_development_dependency "bundler", ">= 1.6", "< 3"
   spec.add_development_dependency "rake",    "~> 13"

lib/hanami-validations.rb

@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+require_relative "hanami/validations"

lib/hanami/validations.rb

@@ -2,14 +2,29 @@
 
 require "dry/validation"
 require "delegate"
+require "zeitwerk"
 
 module Hanami
   # @since 0.1.0
   module Validations
-    class Error < StandardError; end
+    # @since 2.0.0
+    # @api private
+    def self.gem_loader
+      @gem_loader ||= Zeitwerk::Loader.new.tap do |loader|
+        root = File.expand_path("..", __dir__)
+        loader.tag = "hanami-validations"
+        loader.inflector = Zeitwerk::GemInflector.new("#{root}/hanami-validations.rb")
+        loader.push_dir(root)
+        loader.ignore(
+          "#{root}/hanami-validations.rb",
+          "#{root}/hanami/validations/version.rb"
+        )
+      end
+    end
 
-    require "hanami/validations/version"
-    require "hanami/validator"
+    gem_loader.setup
+
+    class Error < StandardError; end
 
     def self.included(klass)
       super

spec/unit/hanami/validator/rule_spec.rb

@@ -10,7 +10,7 @@ RSpec.describe Hanami::Validator do
         end
 
         rule(:email) do
-          key.failure("has invalid format") unless /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i.match?(value)
+          key.failure("has invalid format") unless /\A[\w+\-.]+@[a-z\d-]+(\.[a-z\d-]+)*\.[a-z]+\z/i.match?(value)
         end
 
         rule(:age) do