New #provided_attributes method

README.md

@@ -62,20 +62,32 @@ def name=(value)
 end
 ```
 
-### #attribute_provided?
+### `#provided_attributes` and `#attribute_provided?`
 
-Attribute is considered provided if its setter was explicitly invoked via a setter, `.new`, or `#attributes=` or it has a default value.
+Attribute is considered provided if its setter was explicitly invoked via a setter, `.new`, or `#attributes=`.
 
 ``` ruby
 class Person
   include Tainbox
-  attribute :name, default: 'John'
+  attribute :name, default: 'Anonymous'
   attribute :age
 end
 
-person = Person.new
-person.attribute_provided?(:age) # => false
+person = Person.new('age' => '24')
+
+person.provided_attributes # => [:age]
+person.attribute_provided?(:name) # => false
+person.attribute_provided?(:age) # => true
+
+person.name = 'John'
+person.provided_attributes # => [:name, :age]
 person.attribute_provided?(:name) # => true
+person.attribute_provided?(:age) # => true
+
+person.attributes = {}
+person.provided_attributes # => []
+person.attribute_provided?(:name) # => false
+person.attribute_provided?(:age) # => false
 ```
 
 ### Disabling automatic attribute readers and writers

lib/tainbox/attribute_definer.rb

@@ -41,14 +41,14 @@ def define_setter
       end
 
       define_method("tainbox_set_default_#{attribute}") do
+        tainbox_unregister_attribute_provided(attribute)
+
         if args.has_key?(:default)
-          tainbox_register_attribute_provided(attribute)
           value = args[:default].deep_dup
           value = Tainbox::DeferredValue.new(value) if value.is_a?(Proc)
           instance_variable_set(:"@tainbox_#{attribute}", value)
 
         else
-          tainbox_unregister_attribute_provided(attribute)
           instance_variable_set(:"@tainbox_#{attribute}", nil)
         end
       end

lib/tainbox/instance_methods.rb

@@ -41,6 +41,10 @@ def attributes=(attributes)
     end
   end
 
+  def provided_attributes
+    self.class.tainbox_attributes & tainbox_provided_attributes
+  end
+
   def attribute_provided?(attribute)
     tainbox_provided_attributes.include?(attribute.to_sym)
   end

spec/tainbox_spec.rb

@@ -19,19 +19,23 @@ def name
     expect(person.age).to eq(24)
     expect(person.attribute_provided?(:name)).to be_truthy
     expect(person.attribute_provided?(:age)).to be_truthy
+    expect(person.provided_attributes).to eq(%i[name age])
 
     person.attributes = {}
     expect(person.name).to eq('Oliver')
     expect(person.age).to be_nil
-    expect(person.attribute_provided?(:name)).to be_truthy
+    expect(person.attribute_provided?(:name)).to be_falsey
     expect(person.attribute_provided?(:age)).to be_falsey
 
     expect(person.attributes).to eq(name: 'Oliver', age: nil)
+    expect(person.provided_attributes).to be_empty
 
     person.age = 10
     expect(person.age).to eq(10)
     expect(person.attribute_provided?(:age)).to be_truthy
 
+    expect(person.provided_attributes).to eq(%i[age])
+
     expect(person.as_json).to eq('name' => 'Oliver', 'age' => 10)
     expect(person.as_json(only: :name)).to eq('name' => 'Oliver')
     expect(person.as_json(except: :name)).to eq('age' => 10)