Test object allocation

.travis.yml

@@ -22,7 +22,7 @@ env:
   - DB=postgres ORM=sequel SEQUEL_VERSION=4.46
   - DB=mysql ORM=sequel SEQUEL_VERSION=4.46
   - DB=sqlite3 ORM=sequel SEQUEL_VERSION=4.46
-  - DB=sqlite3 ORM=
+  - DB=sqlite3 ORM= TEST_PERFORMANCE=true
 before_script:
   - bundle exec rake db:create db:up
 before_install: gem install bundler -v 1.12.5

Gemfile

@@ -21,6 +21,8 @@ group :development, :test do
     end
   end
 
+  gem 'allocation_stats' if ENV['TEST_PERFORMANCE']
+
   platforms :ruby do
     gem 'guard-rspec'
     gem 'pry-byebug'

lib/mobility/backend.rb

@@ -97,7 +97,8 @@ def self.included(base)
     # @param [String] attribute
     # @return [String] name of backend reader method
     def self.method_name(attribute)
-      "#{attribute}_backend".freeze
+      @backend_method_names ||= {}
+      @backend_method_names[attribute] ||= "#{attribute}_backend".freeze
     end
 
     # Defines setup hooks for backend to customize model class.

lib/mobility/backend/cache.rb

@@ -44,7 +44,7 @@ def self.apply(attributes, option_value)
       # @!macro backend_reader
       # @option options [Boolean] cache
       #   *false* to disable cache.
-      def read(locale, **options)
+      def read(locale, options = {})
         return super if options.delete(:cache) == false
         if write_to_cache? || cache.has_key?(locale)
           cache[locale]
@@ -56,7 +56,7 @@ def read(locale, **options)
       # @!macro backend_writer
       # @option options [Boolean] cache
       #   *false* to disable cache.
-      def write(locale, value, **options)
+      def write(locale, value, options = {})
         return super if options.delete(:cache) == false
         cache[locale] = write_to_cache? ? value : super
       end
@@ -69,7 +69,7 @@ def write(locale, value, **options)
       module Setup
         # @param model_class Model class
         # @param [Array<String>] attributes Backend attributes
-        def setup_model(model_class, attributes, **_)
+        def setup_model(model_class, attributes, _options = {})
           super
           model_class.include BackendResetter.for(model_class).new(attributes) { clear_cache }
         end

lib/mobility/backend/default.rb

@@ -59,9 +59,9 @@ def self.apply(attributes, option)
       end
 
       def initialize(default_option)
-        define_method :read do |locale, **options|
+        define_method :read do |locale, options = {}|
           default = options.has_key?(:default) ? options.delete(:default) : default_option
-          if (value = super(locale, **options)).nil?
+          if (value = super(locale, options)).nil?
             default.is_a?(Proc) ? default.call(model: model, attribute: attribute) : default
           else
             value

lib/mobility/backend/fallbacks.rb

@@ -90,14 +90,14 @@ def initialize(fallbacks_option)
       private
 
       def define_read(fallbacks)
-        define_method :read do |locale, **options|
+        define_method :read do |locale, options = {}|
           fallback = options.delete(:fallback)
 
           if fallback == false || (fallback.nil? && fallbacks.nil?)
-            super(locale, **options)
+            super(locale, options)
           else
             (fallback ? [locale, *fallback] : fallbacks[locale]).detect do |fallback_locale|
-              value = super(fallback_locale, **options)
+              value = super(fallback_locale, options)
               break value if value.present?
             end
           end

lib/mobility/backend/null.rb

@@ -10,14 +10,14 @@ class Null
 
       # @!group Backend Accessors
       # @return [NilClass]
-      def read(*); end
+      def read(_locale, _options = {}); end
 
       # @return [NilClass]
-      def write(*); end
+      def write(_locale, _value, _options = {}); end
       # @!endgroup
 
       # @!group Backend Configuration
-      def self.configure(*); end
+      def self.configure(_options); end
       # @!endgroup
     end
   end

lib/mobility/backend/presence.rb

@@ -18,7 +18,7 @@ def self.apply(attributes, option)
       # @!macro backend_reader
       # @option options [Boolean] presence
       #   *false* to disable presence filter.
-      def read(locale, **options)
+      def read(locale, options = {})
         return super if options.delete(:presence) == false
         value = super
         value == false ? value : value.presence
@@ -28,9 +28,9 @@ def read(locale, **options)
       # @!macro backend_writer
       # @option options [Boolean] presence
       #   *false* to disable presence filter.
-      def write(locale, value, **options)
+      def write(locale, value, options = {})
         return super if options.delete(:presence) == false
-        super(locale, value == false ? value : value.presence, **options)
+        super(locale, value == false ? value : value.presence, options)
       end
     end
   end

lib/mobility/core_ext/string.rb

@@ -7,7 +7,7 @@
 class String
   # paraphrased from activesupport
   def camelize
-    sub(/^[a-z\d]*/) { $&.capitalize }.gsub(/(?:_|(\/))([a-z\d]*)/) { "#{$1}#{$2.capitalize}" }.gsub('/', '::')
+    sub(/^[a-z\d]*/) { $&.capitalize }.gsub(/(?:_|(\/))([a-z\d]*)/) { "#{$1}#{$2.capitalize}" }.gsub('/'.freeze, '::'.freeze)
   end
 
   def present?

spec/performance/attributes_spec.rb

@@ -0,0 +1,43 @@
+require "spec_helper"
+
+describe Mobility::Attributes do
+  describe "initializing" do
+    specify {
+      expect { described_class.new(:accessor, backend: :null) }.to allocate_under(9).objects
+    }
+  end
+
+  describe "including into a class" do
+    specify {
+      klass = Class.new do
+        include Mobility
+      end
+      attributes = described_class.new(:accessor, backend: :null)
+      expect { klass.include attributes }.to allocate_under(30).objects
+    }
+  end
+
+  describe "accessors" do
+    let(:klass) do
+      Class.new do
+        include Mobility
+        translates :title, backend: :null
+      end
+    end
+
+    describe "calling attribute getter" do
+      specify {
+        instance = klass.new
+        expect { 3.times { instance.title } }.to allocate_under(5).objects
+      }
+    end
+
+    describe "calling attribute setter" do
+      specify {
+        instance = klass.new
+        title = "foo"
+        expect { 3.times { instance.title = title } }.to allocate_under(5).objects
+      }
+    end
+  end
+end

spec/performance/configuration_spec.rb

@@ -0,0 +1,9 @@
+require "spec_helper"
+
+describe Mobility::Configuration do
+  context "when initializing" do
+    specify {
+      expect { described_class.new }.to allocate_under(7).objects
+    }
+  end
+end

spec/spec_helper.rb

@@ -12,6 +12,7 @@
 require 'pry-byebug'
 require 'i18n'
 require 'rspec'
+require 'allocation_stats' if ENV['TEST_PERFORMANCE']
 require 'json'
 
 require 'mobility'

spec/support/matchers/allocate_under.rb

@@ -0,0 +1,34 @@
+# borrowed from: https://blog.honeybadger.io/testing-object-allocations/
+begin
+  require 'allocation_stats'
+rescue LoadError
+  puts 'Skipping AllocationStats.'
+end
+
+RSpec::Matchers.define :allocate_under do |expected|
+  match do |actual|
+    return skip('AllocationStats is not available: skipping.') unless defined?(AllocationStats)
+    @trace = actual.is_a?(Proc) ? AllocationStats.new(burn: 1).trace(&actual) : actual
+    @trace.new_allocations.size < expected
+  end
+
+  def objects
+    self
+  end
+
+  def supports_block_expectations?
+    true
+  end
+
+  def output_trace_info(trace)
+    trace.allocations(alias_paths: true).group_by(:sourcefile, :sourceline, :class).to_text
+  end
+
+  failure_message do |actual|
+    "expected under #{ expected } objects to be allocated; got #{ @trace.new_allocations.size }:\n\n" << output_trace_info(@trace)
+  end
+
+  description do
+    "allocates under #{ expected } objects"
+  end
+end