spaced.rb in spaced-0.3.0

- old
+ new

@@ -1,8 +1,9 @@
 # frozen_string_literal: true
 
 require_relative "spaced/version"
+require "forwardable"
 
 module Spaced
   def self.included(base)
     base.extend ClassMethods
   end
@@ -13,24 +14,49 @@
     attr_reader :parent
   end
 
   module ClassMethods
     def namespace(name, klass = nil, &)
-      unless klass
+      if klass
+        raise "#{klass} must be a subclass of Spaced::Base" unless klass < Spaced::Base
+      else
         class_name = name.to_s.split("_").collect(&:capitalize).join
         klass = eval <<-RUBY, binding, __FILE__, __LINE__ + 1 # rubocop:disable Security/Eval
         #{self}::#{class_name} = Class.new(Base, &)  # Parent::Namespace = Class.new(Base, &)
         RUBY
       end
 
       inst_name = :"@#{name}"
+
+      # Define the memoized namespace method.
       define_method name do
         if instance_variable_defined?(inst_name)
           instance_variable_get inst_name
         else
           cls = klass.new
           cls.instance_variable_set :@parent, self
           instance_variable_set inst_name, cls
+        end
+      end
+
+      # Define the bang and predicate methods.
+      methods = klass.instance_methods(false)
+
+      if methods.include?(:call) || methods.include?(:predicate)
+        extend Forwardable
+        def_delegator :"#{name}", :call, :"#{name}!" if methods.include?(:call)
+        def_delegator :"#{name}", :predicate, :"#{name}?" if methods.include?(:predicate)
+      else
+        unless methods.include?(:call)
+          define_method :"#{name}!" do
+            raise NoMethodError, "undefined method `#{name}!' for #<#{klass}>. Have you defined `#{klass}#call`?"
+          end
+        end
+
+        unless methods.include?(:predicate)
+          define_method :"#{name}?" do
+            raise NoMethodError, "undefined method `#{name}?' for #<#{klass}>. Have you defined `#{klass}#predicate`?"
+          end
         end
       end
     end
   end
 end