Ensure localized slug creates index for slug default locale sub-field when "localize: true" is specified

.rubocop.yml

@@ -5,4 +5,7 @@ AllCops:
 Style/Documentation:
   Enabled: false
 
+Style/ModuleFunction:
+  EnforcedStyle: extend_self
+
 inherit_from: .rubocop_todo.yml

CHANGELOG.md

@@ -1,6 +1,11 @@
-## 6.0.1 (Next)
+## 6.0.2 (Next)
 
 * Your contribution here.
+
+## 6.0.1 (2021/08/12)
+
+* [#243](https://github.com/mongoid/mongoid-slug/pull/266): Ensure localized slugs index expected localized slug fields - [@onomated](https://github.com/onomated), [@johnnyshields](https://github.com/johnnyshields).
+* [#265](https://github.com/mongoid/mongoid-slug/pull/265): Add Github Actions and remove Travis CI - [@johnnyshields](https://github.com/kailan).
 * [#255](https://github.com/mongoid/mongoid-slug/pull/255): Use mongoid::config#models in rake task, resolves #247 - [@kailan](https://github.com/kailan).
 
 ## 6.0.0 (2018/09/17)

README.md

@@ -46,6 +46,7 @@ Mongoid Slug will attempt to determine whether you want to find using the `slugs
 ```ruby
 Book.fields['_id'].type
 => String
+
 book = Book.find 'a-thousand-plateaus' # Finds by slugs
 => ...
 
@@ -61,8 +62,10 @@ end
 
 Post.fields['_id'].type
 => String
+
 post = Post.find 'a-thousand-plateaus' # Finds by slugs
 => ...
+
 post = Post.find '50b1386a0482939864000001' # Finds by bson ids
 => ...
 ```
@@ -271,7 +274,8 @@ Specifying an array of custom reserved words will overwrite these defaults.
 
 ### Localize Slugs
 
-The slugs can be localized:
+The slugs can be localized. This feature is built upon Mongoid localized fields,
+so fallbacks and localization works as documented in the Mongoid manual.
 
 ```ruby
 class PageSlugLocalize
@@ -283,7 +287,28 @@ class PageSlugLocalize
 end
 ```
 
-This feature is built upon Mongoid localized fields, so fallbacks and localization works as documented in the Mongoid manual.
+By specifying `localize: true`, the slug index will be created on the
+[I18n.default_locale](http://guides.rubyonrails.org/i18n.html#the-public-i18n-api) field only.
+For example, if `I18n.default_locale` is `:en`, the index will be generated as follows:
+
+```ruby
+slug :title, localize: true
+
+# The following indexes is auto-generated:
+index({ '_slugs.en' => 1 }, { unique: true, sparse: true })
+```
+
+If you are supporting multiple locales, you may specify the list of locales on which
+to create indexes as an `Array`.
+
+```ruby
+slug :title, localize: [:fr, :es, :de]
+
+# The following indexes are auto-generated:
+index({ '_slugs.fr' => 1 }, { unique: true, sparse: true })
+index({ '_slugs.es' => 1 }, { unique: true, sparse: true })
+index({ '_slugs.de' => 1 }, { unique: true, sparse: true })
+```
 
 ### Custom Find Strategies
 

lib/mongoid/slug.rb

@@ -1,7 +1,7 @@
 require 'mongoid'
 require 'stringex'
 require 'mongoid/slug/criteria'
-require 'mongoid/slug/index'
+require 'mongoid/slug/index_builder'
 require 'mongoid/slug/unique_slug'
 require 'mongoid/slug/slug_id_strategy'
 require 'mongoid-compatibility'
@@ -84,8 +84,8 @@ def slug(*fields, &block)
         field :_slugs, type: Array, localize: options[:localize]
         alias_attribute :slugs, :_slugs
 
-        # Set index
-        index(*Mongoid::Slug::Index.build_index(slug_scope_key, slug_by_model_type)) unless embedded?
+        # Set indexes
+        Mongoid::Slug::IndexBuilder.build_indexes(self, slug_scope_key, slug_by_model_type, options[:localize]) unless embedded?
 
         self.slug_url_builder = block_given? ? block : default_slug_url_builder
 

lib/mongoid/slug/index.rb → lib/mongoid/slug/index_builder.rb

@@ -1,17 +1,39 @@
 module Mongoid
   module Slug
-    module Index
-      # @param [ String or Symbol ] scope_key The optional scope key for the index
-      # @param [ Boolean ] by_model_type Whether or not
+    module IndexBuilder
+      extend self
+
+      # Creates indexes on a document for a given slug scope
+      #
+      # @param [ Mongoid::Document ] doc The document on which to create the index(es)
+      # @param [ String or Symbol ] scope_key The optional scope key for the index(es)
+      # @param [ Boolean ] by_model_type Whether or not to use single table inheritance
+      # @param [ Boolean or Array ] localize The locale for localized index field
       #
       # @return [ Array(Hash, Hash) ] the indexable fields and index options.
-      def self.build_index(scope_key = nil, by_model_type = false)
+      def build_indexes(doc, scope_key = nil, by_model_type = false, locales = nil)
+        if locales.is_a?(Array)
+          locales.each { |locale| build_index(doc, scope_key, by_model_type, locale) }
+        else
+          build_index(doc, scope_key, by_model_type, locales)
+        end
+      end
+
+      private
+
+      def build_index(doc, scope_key = nil, by_model_type = false, locale = nil)
         # The order of field keys is intentional.
         # See: http://docs.mongodb.org/manual/core/index-compound/
         fields = {}
-        fields[:_type] = 1       if by_model_type
+        fields[:_type] = 1 if by_model_type
         fields[scope_key] = 1 if scope_key
-        fields[:_slugs] = 1
+
+        locale = ::I18n.default_locale if locale.is_a?(TrueClass)
+        if locale
+          fields[:"_slugs.#{locale}"] = 1
+        else
+          fields[:_slugs] = 1
+        end
 
         # By design, we use the unique index constraint when possible to enforce slug uniqueness.
         # When migrating legacy data to Mongoid slug, the _slugs field may be null on many records,
@@ -38,7 +60,7 @@ def self.build_index(scope_key = nil, by_model_type = false)
           options[:sparse] = true
         end
 
-        [fields, options]
+        doc.index(fields, options)
       end
     end
   end

spec/mongoid/index_builder_spec.rb

@@ -0,0 +1,105 @@
+require 'spec_helper'
+
+describe Mongoid::Slug::IndexBuilder do
+  let(:doc) { Class.new.include(Mongoid::Document) }
+  let(:scope_key) { nil }
+  let(:by_model_type) { false }
+  let(:default_locale) { :en }
+  let(:locales) { nil }
+
+  subject do
+    if Mongoid::Compatibility::Version.mongoid3?
+      doc.index_options.to_a
+    else
+      doc.index_specifications.map { |spec| [spec.key, spec.options] }
+    end
+  end
+
+  before do
+    allow(I18n).to receive(:default_locale).and_return(default_locale)
+    Mongoid::Slug::IndexBuilder.build_indexes(doc, scope_key, by_model_type, locales)
+  end
+
+  context 'when scope_key is set' do
+    let(:scope_key) { :foo }
+
+    context 'when by_model_type is true' do
+      let(:by_model_type) { true }
+
+      it { is_expected.to eq [[{ _slugs: 1, foo: 1, _type: 1 }, {}]] }
+    end
+
+    context 'when by_model_type is false' do
+      it { is_expected.to eq [[{ _slugs: 1, foo: 1 }, {}]] }
+    end
+
+    context 'when locale is set' do
+      let(:default_locale) { :de }
+      let(:locales) { true }
+
+      it { is_expected.to eq [[{ :'_slugs.de' => 1, foo: 1 }, {}]] }
+    end
+
+    context 'when locale is not set' do
+      it { is_expected.to eq [[{ _slugs: 1, foo: 1 }, {}]] }
+    end
+
+    context 'when locales is an Array' do
+      let(:locales) { %i[es de fr] }
+
+      it do
+        is_expected.to eq [[{ :'_slugs.es' => 1, foo: 1 }, {}],
+                           [{ :'_slugs.de' => 1, foo: 1 }, {}],
+                           [{ :'_slugs.fr' => 1, foo: 1 }, {}]]
+      end
+    end
+  end
+
+  context 'when scope_key is not set' do
+    context 'when by_model_type is true' do
+      let(:by_model_type) { true }
+
+      it { is_expected.to eq [[{ _slugs: 1, _type: 1 }, {}]] }
+    end
+
+    context 'when by_model_type is false' do
+      it { is_expected.to eq [[{ _slugs: 1 }, { unique: true, sparse: true }]] }
+    end
+
+    context 'when locales is true' do
+      let(:locales) { true }
+
+      it { is_expected.to eq [[{ :'_slugs.en' => 1 }, { unique: true, sparse: true }]] }
+    end
+
+    context 'when locales is a String' do
+      let(:locales) { 'de' }
+
+      it { is_expected.to eq [[{ :'_slugs.de' => 1 }, { unique: true, sparse: true }]] }
+    end
+
+    context 'when locales is a Symbol' do
+      let(:locales) { :de }
+
+      it { is_expected.to eq [[{ :'_slugs.de' => 1 }, { unique: true, sparse: true }]] }
+    end
+
+    context 'when locales is an Array' do
+      let(:locales) { %i[es de fr] }
+
+      it do
+        is_expected.to eq [[{ :'_slugs.es' => 1 }, { unique: true, sparse: true }],
+                           [{ :'_slugs.de' => 1 }, { unique: true, sparse: true }],
+                           [{ :'_slugs.fr' => 1 }, { unique: true, sparse: true }]]
+      end
+    end
+
+    context 'when locale is set and by_model_type is true' do
+      let(:locales) { true }
+      let(:default_locale) { :fr }
+      let(:by_model_type) { true }
+
+      it { is_expected.to eq [[{ :'_slugs.fr' => 1, _type: 1 }, {}]] }
+    end
+  end
+end