adding i18n support

This adds translations for filter types, interaction names, attribute
names, and validation errors. All of them are scoped to
:active_interaction.

lib/active_interaction.rb

@@ -20,5 +20,7 @@
 require 'active_interaction/filters/time_filter'
 require 'active_interaction/base'
 
+I18n.backend.load_translations(Dir['lib/active_interaction/locale/*.yml'])
+
 # @since 0.1.0
 module ActiveInteraction end

lib/active_interaction/base.rb

@@ -44,6 +44,10 @@ def persisted?
       false
     end
 
+    def self.i18n_scope
+      :active_interaction
+    end
+
     extend OverloadHash
 
     # Returns the output from {#execute} if there are no validation errors or
@@ -191,12 +195,13 @@ def self.set_up_validator(attribute, type, filter, options, &block)
         begin
           filter.prepare(attribute, send(attribute), options, &block)
         rescue InvalidNestedValue
-          errors.add(attribute, 'is invalid')
+          errors.add(attribute, :invalid_nested)
         rescue InvalidValue
-          errors.add(attribute,
-                     "is not a valid #{type.to_s.humanize.downcase}")
+          errors.add(attribute, :invalid,
+            type: I18n.translate(:"#{self.class.i18n_scope}.types.#{type.to_s}")
+          )
         rescue MissingValue
-          errors.add(attribute, 'is required')
+          errors.add(attribute, :missing)
         end
       end
       private validator

lib/active_interaction/locale/en.yml

@@ -0,0 +1,19 @@
+en:
+  active_interaction:
+    types:
+      array: 'array'
+      boolean: 'boolean'
+      date: 'date'
+      date_time: 'date_time'
+      file: 'file'
+      float: 'float'
+      hash: 'hash'
+      integer: 'integer'
+      model: 'model'
+      string: 'string'
+      time: 'time'
+    errors:
+      messages:
+        invalid_nested: 'is invalid'
+        invalid: 'is not a valid %{type}'
+        missing: 'is required'

spec/active_interaction/base_spec.rb

@@ -234,4 +234,10 @@ def execute; end
       expect(interaction).to_not be_persisted
     end
   end
+
+  describe '.i18n_scope' do
+    it 'returns the scope' do
+      expect(described_class.i18n_scope).to eq :active_interaction
+    end
+  end
 end

spec/active_interaction/i18n_spec.rb

@@ -0,0 +1,161 @@
+require 'spec_helper'
+
+describe 'I18n' do
+  class I18nTest < ActiveInteraction::Base
+    hash :thing do
+      integer :i
+    end
+
+    def execute; end
+  end
+
+  context 'types' do
+    before do
+      I18n.locale = :en
+    end
+
+    [
+      :array,
+      :boolean,
+      :date,
+      :date_time,
+      :file,
+      :float,
+      :hash,
+      :integer,
+      :model,
+      :string,
+      :time
+    ].each do |type|
+      it "has a value for #{type} in English" do
+        expect(I18n.translate(:"active_interaction.types.#{type}")).to eq type.to_s
+      end
+    end
+  end
+
+  context 'model name' do
+    let(:model_name) { 'Internationalization Test' }
+
+    before do
+      I18n.locale = :en
+
+      I18n.backend.store_translations :en, active_interaction: {
+        models: {
+          i18n_test: {
+            one: model_name,
+            other: model_name + 's'
+          }}}
+    end
+
+    it 'returns the translated version of the singular model name' do
+      expect(I18nTest.model_name.human).to eq model_name
+    end
+
+    it 'returns the translated version of the plural model name' do
+      expect(I18nTest.model_name.human(count: 2)).to eq model_name + 's'
+    end
+  end
+
+  context 'attributes' do
+    let(:attr_name) { 'Thing' }
+
+    context 'default' do
+      it 'returns a humanized version of the attribute name' do
+        expect(I18nTest.human_attribute_name(:thing)).to eq attr_name
+      end
+    end
+
+    context 'translated' do
+      let(:attr_name) { 'Thing'.downcase.reverse.capitalize }
+
+      before do
+        I18n.locale = :reverse
+
+        I18n.backend.store_translations :reverse, active_interaction: {
+          attributes: {
+            i18n_test: {
+              thing: attr_name
+            }}}
+      end
+
+      it 'returns a translated version of the attribute name' do
+        expect(
+          I18nTest.human_attribute_name(:thing)
+        ).to eq attr_name
+      end
+    end
+  end
+
+  context 'validations' do
+    context 'default' do
+      before do
+        I18n.locale = :en
+      end
+
+      context ':invalid_nested' do
+        it 'returns "is invalid" in English' do
+          expect(
+            I18nTest.run(thing: {i: Object.new}).errors[:thing]
+          ).to eq ['is invalid']
+        end
+      end
+
+      context ':invalid' do
+        it 'returns "is not a valid hash" in English' do
+          expect(
+            I18nTest.run(thing: Object.new).errors[:thing]
+          ).to eq ['is not a valid hash']
+        end
+      end
+
+      context ':missing' do
+        it 'returns "is required" in English' do
+          expect(
+            I18nTest.run().errors[:thing]
+          ).to eq ['is required']
+        end
+      end
+    end
+
+    context 'translated' do
+      before do
+        I18n.locale = :reverse
+
+        I18n.backend.store_translations :reverse, active_interaction: {
+          types: {
+            hash: 'hash'.reverse
+          },
+          errors: {
+            messages: {
+              invalid_nested: 'is invalid'.reverse,
+              invalid:        "%{type} #{'is not a valid'.reverse}",
+              missing:        'is required'.reverse
+            }}}
+      end
+
+      context ':invalid_nested' do
+        it 'returns "is invalid" translated' do
+          expect(
+            I18nTest.run(thing: {i: Object.new}).errors[:thing]
+          ).to eq ['is invalid'.reverse]
+        end
+      end
+
+      context ':invalid' do
+        it 'returns "is not a valid hash" translated' do
+          expect(
+            I18nTest.run(thing: Object.new).errors[:thing]
+          ).to eq ['is not a valid hash'.reverse]
+        end
+      end
+
+      context ':missing' do
+        it 'returns "is required" translated' do
+          expect(
+            I18nTest.run().errors[:thing]
+          ).to eq ['is required'.reverse]
+        end
+      end
+    end
+  end
+end

spec/support/interactions.rb

@@ -27,6 +27,16 @@ def execute
           defaults_2: defaults_2
         }
       end
+
+      # This causes the tests to fail with:
+      #   Class name cannot be blank. You need to supply a name argument when
+      #   anonymous class given
+      #
+      # In particular adding an error in the MissingValue rescue inside
+      # self.set_up_validator triggers the exception.
+      def self.model_name
+        ActiveModel::Name.new(self, nil, 'Temp')
+      end
     end
   end