Merge pull request #6 from doits/lower_gc_pressure

Lower gc pressure

.travis.yml

@@ -1 +1,10 @@
 language: ruby
+rvm:
+  - 2.0
+  - 2.1
+  - 2.2.5
+  - 2.3.1
+  - ruby-head
+matrix:
+  allow_failures:
+    - rvm: ruby-head

i18n-globals.gemspec

@@ -18,6 +18,8 @@ Gem::Specification.new do |spec|
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ['lib']
 
+  spec.required_ruby_version = '>= 2.0'
+
   spec.add_development_dependency 'bundler', '~> 1.6'
   spec.add_development_dependency 'rake'
   spec.add_development_dependency 'minitest'

lib/i18n/globals.rb

@@ -2,6 +2,8 @@
 require 'i18n/globals/version'
 
 module I18n
+  FAKE_INTERPOLATION_HASH = { fake_: :_interpolation }.freeze
+
   class Config
     class CachedGlobals < Hash
       def []=(key, val)
@@ -79,15 +81,33 @@ def globals
     def globals=(new_globals)
       globals.clear.merge!(new_globals) # maybe there is something better than `clear` and `merge!`
     end
+
+    prepend(
+      Module.new do
+        def missing_interpolation_argument_handler
+          @@missing_interpolation_argument_handler_with_globals ||=
+            lambda do |missing_key, provided_hash, string|
+              # Since the key was not found in a interpolation variable, check
+              # whether it is a global. If it is, return it, so interpolation is
+              # successfull.
+              if globals.for_locale(locale).key?(missing_key)
+                globals.for_locale(locale)[missing_key]
+              else
+                super.call(missing_key, provided_hash, string)
+              end
+            end
+        end
+      end
+    )
   end
 
   class << self
     def translate(*args)
-      if args.last.is_a?(Hash)
-        args[-1] = config.globals.for_locale(locale).merge(args.last)
-      else
-        args << config.globals.for_locale(locale)
-      end
+      # If last argument is a hash, interpolation will be run. If not, it will
+      # not even attempt to interpolate something and our custom
+      # `missing_interpolation_argument_handler` will not be run at all. Thats
+      # why we pass in a fake hash so that it always runs interpolation.
+      args << FAKE_INTERPOLATION_HASH unless args.last.is_a?(Hash)
       super(*args)
     end
 

test/test_i18n_globals.rb

@@ -168,4 +168,49 @@ def test_that_cache_is_cleared_after_merging_a_new_global
 
     assert_equal 'Hi there, Dobby!', I18n.translate('greeting')
   end
+
+  def test_it_still_fails_on_missing_interpolation
+    assert_raises(I18n::MissingInterpolationArgument) { I18n.translate('greeting') }
+  end
+
+  def test_it_allows_to_set_a_custom_missing_interpolation_argument_handler
+    I18n.config.missing_interpolation_argument_handler = proc { raise 'works!' }
+
+    assert_raises('works!') { I18n.translate('greeting') }
+
+    I18n.config.missing_interpolation_argument_handler = nil
+  end
+
+  def test_it_translates_globals_with_custom_missing_interpolation_argument_handler
+    I18n.config.missing_interpolation_argument_handler = proc { raise 'works!' }
+
+    I18n.config.globals = {
+      name: 'Greg'
+    }
+
+    assert_equal I18n.translate('greeting'), 'Hi there, Greg!'
+
+    I18n.config.missing_interpolation_argument_handler = nil
+  end
+
+  def test_it_does_not_polute_the_object_space_with_hashes
+    I18n.config.globals = {
+      name: 'Greg'
+    }
+
+    values = { name: 'Dobby' }
+    times = 10_000
+
+    GC.disable
+    count_before = ObjectSpace.each_object(Hash).count
+    times.times { I18n.translate('greeting', values) }
+    count_after = ObjectSpace.each_object(Hash).count
+    GC.enable
+
+    # It looks like I18n.translate by default allocates 2 new hashes
+    # per call. So substract it from the count.
+    created_due_to_globals = count_after - count_before - times * 2
+
+    assert_equal created_due_to_globals, 0
+  end
 end