Virtus::Lite

README.md

@@ -542,6 +542,33 @@ Blog.attribute_set[:posts].member_type.primitive # => Post
 Post.attribute_set[:blog].type.primitive # => Blog
 ```
 
+Virtus::Lite
+------------
+
+Virtus::Lite is a drop-in replacement for Virtus.model that supports the core
+feature set of Virtus (type coercion, custom coercion, and default values),
+while delivering 10x the speed. Many apps will be able to simply replace
+`include Virtus.model` with `include Virtus::Lite` to enjoy this performance
+boost.
+
+```
+Comparison:
+FastAttributes: without values                       :  2326399.8 i/s
+Virtus::Lite: without values                         :   319304.0 i/s - 7.29x slower
+FastAttributes: integer values for integer attributes:    82969.3 i/s - 28.04x slower
+FastAttributes: string values for integer attributes :    64758.7 i/s - 35.92x slower
+Virtus::Lite: string values for integer attributes   :    37270.1 i/s - 62.42x slower
+Virtus::Lite: integer values for integer attributes  :    36577.8 i/s - 63.60x slower
+Virtus: integer values for integer attributes        :    21857.4 i/s - 106.44x slower
+Attrio: integer values for integer attributes        :    11362.2 i/s - 204.75x slower
+Virtus: without values                               :     9551.8 i/s - 243.56x slower
+Attrio: string values for integer attributes         :     9048.5 i/s - 257.10x slower
+Attrio: without values                               :     6876.1 i/s - 338.33x slower
+Virtus: string values for integer attributes         :     3197.6 i/s - 727.55x slower
+```
+
+Adapted from the [fast_attributes benchmark code.](https://github.com/applift/fast_attributes/blob/master/benchmarks/comparison.rb)
+
 Ruby version support
 --------------------
 

lib/virtus.rb

@@ -284,3 +284,5 @@ def self.warn(msg)
 require 'virtus/attribute/collection'
 require 'virtus/attribute/hash'
 require 'virtus/attribute/embedded_value'
+
+require 'virtus/lite'

lib/virtus/lite.rb

@@ -0,0 +1,123 @@
+module Virtus
+  module Lite
+
+    class Boolean; end
+
+    module ClassMethods
+
+      attr_reader :attributes
+      attr_reader :set_attributes
+
+      def attribute( name, type = nil, options = {} )
+        @attributes ||= []
+        @attributes << name unless @attributes.include? name
+        define_method( "#{ name }=") do |value|
+          @set_attributes ||= []
+          @set_attributes << name
+          instance_variable_set "@#{ name }", value
+        end
+        define_method( name ) do
+          value = instance_variable_get "@#{ name }"
+          coercer = options[ :coercer ]
+          default = options[ :default ]
+          if coercer
+            coercer.call value
+          elsif value.nil? and not default.nil? and default.is_a? Symbol and respond_to? default
+            send default
+          else
+            if type.is_a? Array
+              if value.nil?
+                []
+              elsif value.is_a? Array
+                value.map { |v| determine_value name, v, type.first, options }
+              else
+                determine_value name, value, type.first, options
+              end
+            else
+              determine_value name, value, type, options
+            end
+          end
+        end
+        # private :"#{ name }"  if options[ :reader ] == :private
+        # private :"#{ name }=" if options[ :writer ] == :private
+        self
+      end
+    end
+
+    def self.included( base )
+      base.extend ClassMethods
+    end
+
+    def attributes
+      Hash[ self.class.attributes.map { |v| [ v, send( v ) ] } ] || {}
+    end
+
+    def []( key )
+      send( key ) if self.class.attributes.include? key
+    end
+
+    private
+
+    def determine_value( name, value, type, options )
+      default = options[ :default ]
+      if value.nil? and not default.nil?
+        value = default
+      elsif type and not value.is_a? type
+        if not value.nil? and @set_attributes.include? name
+          if value.is_a? Hash and not type.is_a? Hash
+            value = type.new value
+          else
+            value = convert value, type
+          end
+        end
+      end
+      value
+    end
+
+    def initialize( params = {} )
+      unless params.nil?
+        params.each do |name, value|
+          self.send( :"#{name}=", value ) if respond_to? "#{ name }="
+        end
+      end
+      self.class.send( :define_method, :to_hash ) do
+        Hash[ self.class.attributes.map { |attribute| [ attribute, send( attribute ) ] } ]
+      end
+    end
+
+    def convert( value, type )
+      case type.to_s
+      when 'String'
+        value.to_s
+      when 'Integer', 'Fixnum', 'Bignum'
+        if value.respond_to? :to_i
+          value.to_i
+        elsif value.is_a? TrueClass or value.is_a? FalseClass
+          value ? 1 : 0
+        else
+          0
+        end
+      when 'Float'
+        if value.respond_to? :to_f
+          value.to_f
+        elsif value.is_a? TrueClass or value.is_a? FalseClass
+          value ? 1.0 : 0.0
+        end
+      when 'Virtus::Attribute::Boolean', 'Virtus::Lite::Boolean'
+        if value.nil?
+          false
+        elsif value.is_a? String
+          value != ''
+        elsif value.is_a? Integer
+          value != 0
+        elsif value.is_a? TrueClass or value.is_a? FalseClass
+          value
+        elsif value.is_a? Float
+          value != 0.0
+        else
+          true
+        end
+      end
+    end
+  end
+end

spec/unit/virtus/lite/array_integer_spec.rb

@@ -0,0 +1,33 @@
+require 'spec_helper'
+
+class PlainArrayIntegerTest
+  include Virtus::Lite
+  attribute :fish, Array[Integer]
+end
+
+describe PlainArrayIntegerTest do
+  before do
+    @test = PlainArrayIntegerTest.new
+  end
+
+  it 'returns array of integers when set to array of strings' do
+    @test.fish = [ 'red', 'blue' ]
+    expect( @test.fish ).to eq( [ 0, 0 ] )
+  end
+  it 'returns array of integers when set to array of integers' do
+    @test.fish = [ 1, 2 ]
+    expect( @test.fish ).to eq( [ 1, 2 ] )
+  end
+  it 'returns array of integers when set to array of booleans' do
+    @test.fish = [ true, false ]
+    expect( @test.fish ).to eq( [ 1, 0 ] )
+  end
+  it 'returns array of integers when set to array of floats' do
+    @test.fish = [ 7.6, 23.5 ]
+    expect( @test.fish ).to eq( [ 7, 23 ] )
+  end
+  it 'returns array of integers when set to a mixed array' do
+    @test.fish = [ 'red', 42, false, 34.5, Integer ]
+    expect( @test.fish ).to eq( [ 0, 42, 0, 34, 0 ] )
+  end
+end

spec/unit/virtus/lite/array_integer_spec.rb-e

@@ -0,0 +1,33 @@
+require 'spec_helper'
+
+class PlainArrayIntegerTest
+  include Subvirtus
+  attribute :fish, Array[Integer]
+end
+
+describe PlainArrayIntegerTest do
+  before do
+    @test = PlainArrayIntegerTest.new
+  end
+
+  it 'returns array of integers when set to array of strings' do
+    @test.fish = [ 'red', 'blue' ]
+    expect( @test.fish ).to eq( [ 0, 0 ] )
+  end
+  it 'returns array of integers when set to array of integers' do
+    @test.fish = [ 1, 2 ]
+    expect( @test.fish ).to eq( [ 1, 2 ] )
+  end
+  it 'returns array of integers when set to array of booleans' do
+    @test.fish = [ true, false ]
+    expect( @test.fish ).to eq( [ 1, 0 ] )
+  end
+  it 'returns array of integers when set to array of floats' do
+    @test.fish = [ 7.6, 23.5 ]
+    expect( @test.fish ).to eq( [ 7, 23 ] )
+  end
+  it 'returns array of integers when set to a mixed array' do
+    @test.fish = [ 'red', 42, false, 34.5, Integer ]
+    expect( @test.fish ).to eq( [ 0, 42, 0, 34, 0 ] )
+  end
+end

spec/unit/virtus/lite/array_string_spec.rb

@@ -0,0 +1,33 @@
+require 'spec_helper'
+
+class PlainArrayStringTest
+  include Virtus::Lite
+  attribute :fish, Array[String]
+end
+
+describe PlainArrayStringTest do
+  before do
+    @test = PlainArrayStringTest.new
+  end
+
+  it 'returns array of strings when set to array of strings' do
+    @test.fish = [ 'red', 'blue' ]
+    expect( @test.fish ).to eq( [ 'red', 'blue' ] )
+  end
+  it 'returns array of strings when set to array of integers' do
+    @test.fish = [ 1, 2 ]
+    expect( @test.fish ).to eq( [ '1', '2' ] )
+  end
+  it 'returns array of strings when set to array of booleans' do
+    @test.fish = [ true, false ]
+    expect( @test.fish ).to eq( [ 'true', 'false' ] )
+  end
+  it 'returns array of strings when set to array of floats' do
+    @test.fish = [ 7.6, 23.5 ]
+    expect( @test.fish ).to eq( [ '7.6', '23.5' ] )
+  end
+  it 'returns array of strings when set to a mixed array' do
+    @test.fish = [ 'red', 42, false, 34.5, String ]
+    expect( @test.fish ).to eq( [ 'red', '42', 'false', '34.5', 'String' ] )
+  end
+end

spec/unit/virtus/lite/array_string_spec.rb-e

@@ -0,0 +1,33 @@
+require 'spec_helper'
+
+class PlainArrayStringTest
+  include Subvirtus
+  attribute :fish, Array[String]
+end
+
+describe PlainArrayStringTest do
+  before do
+    @test = PlainArrayStringTest.new
+  end
+
+  it 'returns array of strings when set to array of strings' do
+    @test.fish = [ 'red', 'blue' ]
+    expect( @test.fish ).to eq( [ 'red', 'blue' ] )
+  end
+  it 'returns array of strings when set to array of integers' do
+    @test.fish = [ 1, 2 ]
+    expect( @test.fish ).to eq( [ '1', '2' ] )
+  end
+  it 'returns array of strings when set to array of booleans' do
+    @test.fish = [ true, false ]
+    expect( @test.fish ).to eq( [ 'true', 'false' ] )
+  end
+  it 'returns array of strings when set to array of floats' do
+    @test.fish = [ 7.6, 23.5 ]
+    expect( @test.fish ).to eq( [ '7.6', '23.5' ] )
+  end
+  it 'returns array of strings when set to a mixed array' do
+    @test.fish = [ 'red', 42, false, 34.5, String ]
+    expect( @test.fish ).to eq( [ 'red', '42', 'false', '34.5', 'String' ] )
+  end
+end

spec/unit/virtus/lite/attribute_spec.rb

@@ -0,0 +1,22 @@
+require 'spec_helper'
+
+describe 'include Virtus::Lite' do
+
+  let :model do
+    Class.new do
+      include Virtus::Lite
+    end
+  end
+
+  it 'responds to #attribute' do
+    expect( model ).to respond_to( :attribute )
+  end
+
+  it 'responds to #attributes' do
+    expect( model ).to respond_to( :attributes )
+  end
+
+  it 'responds to #set_attributes' do
+    expect( model ).to respond_to( :set_attributes )
+  end
+end

spec/unit/virtus/lite/attribute_spec.rb-e

@@ -0,0 +1,22 @@
+require 'spec_helper'
+
+describe 'include Subvirtus' do
+
+  let :model do
+    Class.new do
+      include Subvirtus
+    end
+  end
+
+  it 'responds to #attribute' do
+    expect( model ).to respond_to( :attribute )
+  end
+
+  it 'responds to #attributes' do
+    expect( model ).to respond_to( :attributes )
+  end
+
+  it 'responds to #set_attributes' do
+    expect( model ).to respond_to( :set_attributes )
+  end
+end