base.rb in koine-attributes-0.3.0

- old
+ new

@@ -1,25 +1,46 @@
 module Koine
   module Attributes
     module Adapter
       class Base
-        def coerce(*_values)
-          raise NotImplementedError
+        def coerce(value)
+          return coerce_nil if value.nil?
+
+          coerce_not_nil(value)
         end
 
         def default_value
           @default_value.respond_to?(:call) &&
             @default_value.call ||
             @default_value
         end
 
+        def with_nil_value(value = nil, &block)
+          @nil_value_set = true
+          @nil_value = value
+          @nil_value = block if block
+          self
+        end
+
         def with_default_value(value = nil, &block)
           @default_value = value
           @default_value = block if block
           self
         end
 
-        protected
+        private
+
+        def coerce_nil
+          if @nil_value_set
+            return @nil_value.respond_to?(:call) ? @nil_value.call : @nil_value
+          end
+
+          raise ArgumentError, 'Cannot be nil'
+        end
+
+        def coerce_not_nil(_value)
+          raise NotImplementedError
+        end
 
         # duplicates if possible and freezes object
         def secure
           value = yield
 