Allow Key Format to Be Overridden and Have Sensible Defaults

.gitignore

@@ -21,3 +21,4 @@ tmp
 *.swp
 .ruby-version
 .ruby-gemset
+tags

.rubocop.yml

@@ -65,6 +65,8 @@ Metrics/LineLength:
 
 Metrics/MethodLength:
   Max: 106 # TODO: Lower to 10
+  Exclude:
+    - test/**/*.rb
 
 Metrics/PerceivedComplexity:
   Max: 9 # TODO: Lower to 7

README.md

@@ -187,6 +187,38 @@ class PostSerializer < ActiveModel::Serializer
 end
 ```
 
+### Overriding the Key Format
+
+You can specify that serializers use a different style for the format of the
+keys that are sent over. This can be done globally or at the controller action
+level.
+
+Each adapter has a default format, so typically you're either not going to have
+to change this, or you'll edit the global setting.
+
+For example, the JSON adapter defaults to `lower_camel` whereas the JSON API
+adapter defaults to `dasherize`. Any other adapter will default to `unaltered`.
+
+```ruby
+# Global
+ActiveModel::Serializer.config.key_format = :lower_camel
+
+# Per Controller Action
+class MyController < ActionController::Base
+  def index
+    render json:       my_resource,
+           key_format: :lower_camel
+  end
+end
+```
+
+#### Currently Supported Key Formats ####
+
+* `:unaltered`
+* `:lower_camel`
+* `:underscore`
+* `:dasherize` (aliased to `json_api`)
+
 ### Built in Adapters
 
 #### FlattenJSON

lib/active_model/serializable_resource.rb

@@ -1,7 +1,7 @@
 require 'set'
 module ActiveModel
   class SerializableResource
-    ADAPTER_OPTION_KEYS = Set.new([:include, :fields, :adapter])
+    ADAPTER_OPTION_KEYS = Set.new([:include, :fields, :adapter, :key_format])
 
     # Primary interface to composing a resource with a serializer and adapter.
     # @return the serializable_resource, ready for #as_json/#to_json/#serializable_hash.

lib/active_model/serializer/adapter.rb

@@ -124,6 +124,27 @@ def include_meta(json)
         json[meta_key] = meta if meta
         json
       end
+
+      def key_format
+        instance_options[:key_format] || ActiveModel::Serializer.config.key_format || default_key_format
+      end
+
+      def format_key(formattable_key)
+        case key_format
+        when :lower_camel
+          formattable_key.to_s.camelize(:lower).to_sym
+        when :dasherize, :json_api
+          formattable_key.to_s.underscore.dasherize.to_sym
+        when :underscore
+          formattable_key.to_s.underscore.to_sym
+        else
+          formattable_key
+        end
+      end
+
+      def default_key_format
+        :unaltered
+      end
     end
   end
 end

lib/active_model/serializer/adapter/json.rb

@@ -2,6 +2,7 @@ class ActiveModel::Serializer::Adapter::Json < ActiveModel::Serializer::Adapter
         extend ActiveSupport::Autoload
         autoload :FragmentCache
 
+        # rubocop:disable Metrics/AbcSize
         def serializable_hash(options = nil)
           options ||= {}
           if serializer.respond_to?(:each)
@@ -13,23 +14,39 @@ def serializable_hash(options = nil)
               serializer.attributes(options)
             end
 
+            core = core.each_with_object({}) do |(name, value), formatted_hash|
+              formatted_hash[format_key(name)] = value
+            end
+
             serializer.associations.each do |association|
               serializer = association.serializer
               association_options = association.options
 
               if serializer.respond_to?(:each)
                 array_serializer = serializer
-                hash[association.key] = array_serializer.map do |item|
-                  cache_check(item) do
+                formatted_association_key = format_key(association.key)
+
+                hash[formatted_association_key] = array_serializer.map do |item|
+                  attributes = cache_check(item) do
                     item.attributes(association_options)
                   end
+
+                  attributes.each_with_object({}) do |(name, value), formatted_hash|
+                    formatted_hash[format_key(name)] = value
+                  end
                 end
               else
-                hash[association.key] =
+                formatted_association_key = format_key(association.key)
+
+                hash[formatted_association_key] =
                   if serializer && serializer.object
-                    cache_check(serializer) do
+                    attributes = cache_check(serializer) do
                       serializer.attributes(options)
                     end
+
+                    attributes.each_with_object({}) do |(name, value), formatted_hash|
+                      formatted_hash[format_key(name)] = value
+                    end
                   elsif association_options[:virtual_value]
                     association_options[:virtual_value]
                   end
@@ -40,6 +57,11 @@ def serializable_hash(options = nil)
 
           { root => result }
         end
+        # rubocop:enable Metrics/AbcSize
+
+        def default_key_format
+          :lower_camel
+        end
 
         def fragment_cache(cached_hash, non_cached_hash)
           ActiveModel::Serializer::Adapter::Json::FragmentCache.new().fragment_cache(cached_hash, non_cached_hash)

lib/active_model/serializer/adapter/json_api.rb

@@ -16,6 +16,7 @@ def initialize(serializer, options = {})
 
         def serializable_hash(options = nil)
           options ||= {}
+
           if serializer.respond_to?(:each)
             serializable_hash_for_collection(serializer, options)
           else
@@ -28,6 +29,10 @@ def fragment_cache(cached_hash, non_cached_hash)
           ActiveModel::Serializer::Adapter::JsonApi::FragmentCache.new.fragment_cache(root, cached_hash, non_cached_hash)
         end
 
+        def default_key_format
+          :dasherize
+        end
+
         private
 
         ActiveModel.silence_warnings do
@@ -85,7 +90,7 @@ def resource_identifier_for(serializer)
           type = resource_identifier_type_for(serializer)
           id   = resource_identifier_id_for(serializer)
 
-          { id: id.to_s, type: type }
+          { id: id.to_s, type: format_key(type).to_s }
         end
 
         def resource_object_for(serializer, options = {})
@@ -94,7 +99,15 @@ def resource_object_for(serializer, options = {})
           cache_check(serializer) do
             result = resource_identifier_for(serializer)
             attributes = serializer.attributes(options).except(:id)
-            result[:attributes] = attributes if attributes.any?
+
+            if attributes.any?
+              attributes = attributes.each_with_object({}) do |(name, value), hash|
+                hash[format_key(name)] = value
+              end
+
+              result[:attributes] = attributes
+            end
+
             result
           end
         end
@@ -120,7 +133,17 @@ def relationship_value_for(serializer, options = {})
         end
 
         def relationships_for(serializer)
-          Hash[serializer.associations.map { |association| [association.key, { data: relationship_value_for(association.serializer, association.options) }] }]
+          Hash[
+            serializer.associations.map do |association|
+              [
+                format_key(association.key),
+                {
+                  data: relationship_value_for(association.serializer,
+                    association.options)
+                }
+              ]
+            end
+          ]
         end
 
         def included_for(serializer)

lib/active_model/serializer/configuration.rb

@@ -8,6 +8,7 @@ module Configuration
         base.config.array_serializer = ActiveModel::Serializer::ArraySerializer
         base.config.adapter = :flatten_json
         base.config.jsonapi_resource_type = :plural
+        base.config.key_format = nil
       end
     end
   end

test/action_controller/explicit_serializer_test.rb

@@ -43,8 +43,8 @@ def render_array_using_explicit_serializer_and_custom_serializers
           @author = Author.new(name: 'Jane Blogger')
           @author.posts = [@post]
           @post.author = @author
-          @first_comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
-          @second_comment = Comment.new(id: 2, body: 'ZOMG ANOTHER COMMENT')
+          @first_comment = Comment.new(id: 1, body: 'ZOMG A COMMENT', original_format: 'markdown')
+          @second_comment = Comment.new(id: 2, body: 'ZOMG ANOTHER COMMENT', original_format: 'text')
           @post.comments = [@first_comment, @second_comment]
           @first_comment.post = @post
           @first_comment.author = nil

test/action_controller/serialization_test.rb

@@ -46,7 +46,7 @@ def render_array_using_implicit_serializer_and_meta
         end
 
         def render_object_with_cache_enabled
-          @comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
+          @comment = Comment.new(id: 1, body: 'ZOMG A COMMENT', original_format: 'markdown')
           @author  = Author.new(id: 1, name: 'Joao Moura.')
           @post    = Post.new(id: 1, title: 'New Post', body: 'Body', comments: [@comment], author: @author)
 
@@ -72,7 +72,7 @@ def update_and_render_object_with_cache_enabled
         end
 
         def render_object_expired_with_cache_enabled
-          comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
+          comment = Comment.new(id: 1, body: 'ZOMG A COMMENT', original_format: 'markdown')
           author = Author.new(id: 1, name: 'Joao Moura.')
           post = Post.new(id: 1, title: 'New Post', body: 'Body', comments: [comment], author: author)
 
@@ -91,7 +91,7 @@ def render_object_expired_with_cache_enabled
         end
 
         def render_changed_object_with_cache_enabled
-          comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
+          comment = Comment.new(id: 1, body: 'ZOMG A COMMENT', original_format: 'markdown')
           author = Author.new(id: 1, name: 'Joao Moura.')
           post = Post.new(id: 1, title: 'ZOMG a New Post', body: 'Body', comments: [comment], author: author)
 
@@ -121,7 +121,7 @@ def render_fragment_changed_object_with_except_cache_enabled
         end
 
         def render_fragment_changed_object_with_relationship
-          comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
+          comment = Comment.new(id: 1, body: 'ZOMG A COMMENT', original_format: 'markdown')
           comment2 = Comment.new(id: 1, body: 'ZOMG AN UPDATED-BUT-NOT-CACHE-EXPIRED COMMENT')
           like = Like.new(id: 1, likeable: comment, time: 3.days.ago)
 
@@ -262,7 +262,8 @@ def test_render_with_cache_enable
           comments: [
             {
               id: 1,
-              body: 'ZOMG A COMMENT' }
+              body: 'ZOMG A COMMENT',
+              originalFormat: 'markdown' }
           ],
           blog: {
             id: 999,
@@ -301,7 +302,8 @@ def test_render_with_cache_enable_and_expired
           comments: [
             {
               id: 1,
-              body: 'ZOMG A COMMENT' }
+              body: 'ZOMG A COMMENT',
+              originalFormat: 'markdown' }
           ],
           blog: {
             id: 999,
@@ -355,7 +357,8 @@ def test_render_fragment_changed_object_with_relationship
             'time' => Time.zone.now.to_s,
             'likeable' => {
               'id' => 1,
-              'body' => 'ZOMG A COMMENT'
+              'body' => 'ZOMG A COMMENT',
+              'originalFormat' => 'markdown'
             }
           }
 
@@ -375,7 +378,8 @@ def test_cache_expiration_on_update
           comments: [
             {
               id: 1,
-              body: 'ZOMG A COMMENT' }
+              body: 'ZOMG A COMMENT',
+              originalFormat: 'markdown' }
           ],
           blog: {
             id: 999,

test/adapter/json/belongs_to_test.rb

@@ -8,7 +8,7 @@ class BelongsToTest < Minitest::Test
           def setup
             @post = Post.new(id: 42, title: 'New Post', body: 'Body')
             @anonymous_post = Post.new(id: 43, title: 'Hello!!', body: 'Hello, world!!')
-            @comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
+            @comment = Comment.new(id: 1, body: 'ZOMG A COMMENT', original_format: 'markdown')
             @post.comments = [@comment]
             @anonymous_post.comments = []
             @comment.post = @post

test/adapter/json/collection_test.rb

@@ -28,7 +28,7 @@ def test_with_serializer_option
 
             expected = { blogs: [{
               id: 1,
-              special_attribute: 'Special',
+              specialAttribute: 'Special',
               articles: [{ id: 1, title: 'Hello!!', body: 'Hello, world!!' }, { id: 2, title: 'New Post', body: 'Body' }]
             }] }
             assert_equal expected, adapter.serializable_hash

test/adapter/json/has_many_test.rb

@@ -9,8 +9,8 @@ def setup
             ActionController::Base.cache_store.clear
             @author = Author.new(id: 1, name: 'Steve K.')
             @post = Post.new(id: 42, title: 'New Post', body: 'Body')
-            @first_comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
-            @second_comment = Comment.new(id: 2, body: 'ZOMG ANOTHER COMMENT')
+            @first_comment = Comment.new(id: 1, body: 'ZOMG A COMMENT', original_format: 'markdown')
+            @second_comment = Comment.new(id: 2, body: 'ZOMG ANOTHER COMMENT', original_format: 'text')
             @post.comments = [@first_comment, @second_comment]
             @post.author = @author
             @first_comment.post = @post
@@ -25,8 +25,8 @@ def test_has_many
             serializer = PostSerializer.new(@post)
             adapter = ActiveModel::Serializer::Adapter::Json.new(serializer)
             assert_equal([
-                           { id: 1, body: 'ZOMG A COMMENT' },
-                           { id: 2, body: 'ZOMG ANOTHER COMMENT' }
+                           { id: 1, body: 'ZOMG A COMMENT', originalFormat: 'markdown' },
+                           { id: 2, body: 'ZOMG ANOTHER COMMENT', originalFormat: 'text' }
                          ], adapter.serializable_hash[:post][:comments])
           end