From ac06013aebe4ba92c23b1364421db0900a408cb8 Mon Sep 17 00:00:00 2001
From: Lucas Hosseini <lucas.hosseini@gmail.com>
Date: Wed, 16 Sep 2015 08:45:56 +0200
Subject: [PATCH] Add support for wildcard includes + improve perfs on JsonApi
 includes.

---
 CHANGELOG.md                                  |  1 +
 lib/active_model/serializer.rb                |  2 +-
 .../serializer/adapter/attributes.rb          |  7 +-
 .../serializer/adapter/json_api.rb            | 52 +++++-----
 lib/active_model/serializer/associations.rb   |  6 +-
 lib/active_model/serializer/include_tree.rb   | 75 +++++++++++++++
 lib/active_model/serializer/utils.rb          | 35 -------
 .../action_controller/json_api/linked_test.rb |  6 +-
 test/include_tree/from_include_args_test.rb   | 26 +++++
 test/include_tree/from_string_test.rb         | 94 +++++++++++++++++++
 test/utils/include_args_to_hash_test.rb       | 79 ----------------
 11 files changed, 238 insertions(+), 145 deletions(-)
 create mode 100644 lib/active_model/serializer/include_tree.rb
 delete mode 100644 lib/active_model/serializer/utils.rb
 create mode 100644 test/include_tree/from_include_args_test.rb
 create mode 100644 test/include_tree/from_string_test.rb
 delete mode 100644 test/utils/include_args_to_hash_test.rb

diff --git a/CHANGELOG.md b/CHANGELOG.md
index bc99a7c2..2f90e7fb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,7 @@ Features:
   * adds FlattenJSON as default adapter [@joaomdmoura]
   * adds support for `pagination links` at top level of JsonApi adapter [@bacarini]
   * adds extended format for `include` option to JsonApi adapter [@beauby]
+  * adds support for wildcards in `include` option [@beauby]
 
 Fixes:
 
diff --git a/lib/active_model/serializer.rb b/lib/active_model/serializer.rb
index 62f42751..030e47d2 100644
--- a/lib/active_model/serializer.rb
+++ b/lib/active_model/serializer.rb
@@ -1,11 +1,11 @@
 require 'thread_safe'
 require 'active_model/serializer/adapter'
 require 'active_model/serializer/array_serializer'
+require 'active_model/serializer/include_tree'
 require 'active_model/serializer/associations'
 require 'active_model/serializer/configuration'
 require 'active_model/serializer/fieldset'
 require 'active_model/serializer/lint'
-require 'active_model/serializer/utils'
 
 module ActiveModel
   class Serializer
diff --git a/lib/active_model/serializer/adapter/attributes.rb b/lib/active_model/serializer/adapter/attributes.rb
index 09761a4a..4331f579 100644
--- a/lib/active_model/serializer/adapter/attributes.rb
+++ b/lib/active_model/serializer/adapter/attributes.rb
@@ -2,6 +2,11 @@ module ActiveModel
   class Serializer
     module Adapter
       class Attributes < Base
+        def initialize(serializer, options = {})
+          super
+          @include_tree = IncludeTree.from_include_args(options[:include] || '*')
+        end
+
         def serializable_hash(options = nil)
           options ||= {}
           if serializer.respond_to?(:each)
@@ -13,7 +18,7 @@ module ActiveModel
               serializer.attributes(options)
             end
 
-            serializer.associations.each do |association|
+            serializer.associations(@include_tree).each do |association|
               serializer = association.serializer
               association_options = association.options
 
diff --git a/lib/active_model/serializer/adapter/json_api.rb b/lib/active_model/serializer/adapter/json_api.rb
index 7a028717..3637ccb7 100644
--- a/lib/active_model/serializer/adapter/json_api.rb
+++ b/lib/active_model/serializer/adapter/json_api.rb
@@ -8,7 +8,8 @@ module ActiveModel
 
         def initialize(serializer, options = {})
           super
-          @included = ActiveModel::Serializer::Utils.include_args_to_hash(instance_options[:include])
+          @include_tree = IncludeTree.from_include_args(options[:include])
+
           fields = options.delete(:fields)
           if fields
             @fieldset = ActiveModel::Serializer::Fieldset.new(fields, serializer.json_key)
@@ -19,10 +20,11 @@ module ActiveModel
 
         def serializable_hash(options = nil)
           options ||= {}
+
           if serializer.respond_to?(:each)
-            serializable_hash_for_collection(serializer, options)
+            serializable_hash_for_collection(options)
           else
-            serializable_hash_for_single_resource(serializer, options)
+            serializable_hash_for_single_resource(options)
           end
         end
 
@@ -34,10 +36,10 @@ module ActiveModel
         private
 
         ActiveModel.silence_warnings do
-          attr_reader :included, :fieldset
+          attr_reader :fieldset
         end
 
-        def serializable_hash_for_collection(serializer, options)
+        def serializable_hash_for_collection(options)
           hash = { data: [] }
           serializer.each do |s|
             result = self.class.new(s, instance_options.merge(fieldset: fieldset)).serializable_hash(options)
@@ -57,10 +59,10 @@ module ActiveModel
           hash
         end
 
-        def serializable_hash_for_single_resource(serializer, options)
+        def serializable_hash_for_single_resource(options)
           primary_data = primary_data_for(serializer, options)
           relationships = relationships_for(serializer)
-          included = included_for(serializer)
+          included = included_resources(@include_tree)
           hash = { data: primary_data }
           hash[:data][:relationships] = relationships if relationships.any?
           hash[:included] = included if included.any?
@@ -123,37 +125,37 @@ module ActiveModel
         end
 
         def relationships_for(serializer)
-          Hash[serializer.associations.map { |association| [association.key, { data: relationship_value_for(association.serializer, association.options) }] }]
+          serializer.associations.each_with_object({}) do |association, hash|
+            hash[association.key] = { data: relationship_value_for(association.serializer, association.options) }
+          end
         end
 
-        def included_for(serializer)
-          included.flat_map { |inc|
-            association = serializer.associations.find { |assoc| assoc.key == inc.first }
-            _included_for(association.serializer, inc.second) if association
-          }.uniq
+        def included_resources(include_tree)
+          included = []
+
+          serializer.associations(include_tree).each do |association|
+            add_included_resources_for(association.serializer, include_tree[association.key], included)
+          end
+
+          included
         end
 
-        def _included_for(serializer, includes)
+        def add_included_resources_for(serializer, include_tree, included)
           if serializer.respond_to?(:each)
-            serializer.flat_map { |s| _included_for(s, includes) }.uniq
+            serializer.each { |s| add_included_resources_for(s, include_tree, included) }
           else
-            return [] unless serializer && serializer.object
+            return unless serializer && serializer.object
 
             primary_data = primary_data_for(serializer, instance_options)
             relationships = relationships_for(serializer)
             primary_data[:relationships] = relationships if relationships.any?
 
-            included = [primary_data]
+            return if included.include?(primary_data)
+            included.push(primary_data)
 
-            includes.each do |inc|
-              association = serializer.associations.find { |assoc| assoc.key == inc.first }
-              if association
-                included.concat(_included_for(association.serializer, inc.second))
-                included.uniq!
-              end
+            serializer.associations(include_tree).each do |association|
+              add_included_resources_for(association.serializer, include_tree[association.key], included)
             end
-
-            included
           end
         end
 
diff --git a/lib/active_model/serializer/associations.rb b/lib/active_model/serializer/associations.rb
index 660ff0d1..86c5752c 100644
--- a/lib/active_model/serializer/associations.rb
+++ b/lib/active_model/serializer/associations.rb
@@ -10,6 +10,8 @@ module ActiveModel
     module Associations
       extend ActiveSupport::Concern
 
+      DEFAULT_INCLUDE_TREE = ActiveModel::Serializer::IncludeTree.from_string('*')
+
       included do |base|
         class << base
           attr_accessor :_reflections
@@ -82,13 +84,15 @@ module ActiveModel
         end
       end
 
+      # @param [IncludeTree] include_tree (defaults to all associations when not provided)
       # @return [Enumerator<Association>]
       #
-      def associations
+      def associations(include_tree = DEFAULT_INCLUDE_TREE)
         return unless object
 
         Enumerator.new do |y|
           self.class._reflections.each do |reflection|
+            next unless include_tree.key?(reflection.name)
             y.yield reflection.build_association(self, instance_options)
           end
         end
diff --git a/lib/active_model/serializer/include_tree.rb b/lib/active_model/serializer/include_tree.rb
new file mode 100644
index 00000000..6d675e11
--- /dev/null
+++ b/lib/active_model/serializer/include_tree.rb
@@ -0,0 +1,75 @@
+module ActiveModel
+  class Serializer
+    class IncludeTree
+      module Parsing
+        module_function
+
+        def include_string_to_hash(included)
+          included.delete(' ').split(',').reduce({}) do |hash, path|
+            include_tree = path.split('.').reverse_each.reduce({}) { |a, e| { e.to_sym => a } }
+            hash.deep_merge!(include_tree)
+          end
+        end
+
+        def include_args_to_hash(included)
+          case included
+          when Symbol
+            { included => {} }
+          when Hash
+            included.each_with_object({}) { |(key, value), hash|
+              hash[key] = include_args_to_hash(value)
+            }
+          when Array
+            included.reduce({}) { |a, e| a.merge!(include_args_to_hash(e)) }
+          when String
+            include_string_to_hash(included)
+          else
+            {}
+          end
+        end
+      end
+
+      # Builds an IncludeTree from a comma separated list of dot separated paths (JSON API format).
+      # @example `'posts.author, posts.comments.upvotes, posts.comments.author'`
+      #
+      # @param [String] included
+      # @return [IncludeTree]
+      #
+      def self.from_string(included)
+        new(Parsing.include_string_to_hash(included))
+      end
+
+      # Translates the arguments passed to the include option into an IncludeTree.
+      # The format can be either a String (see #from_string), an Array of Symbols and Hashes, or a mix of both.
+      # @example `posts: [:author, comments: [:author, :upvotes]]`
+      #
+      # @param [Symbol, Hash, Array, String] included
+      # @return [IncludeTree]
+      #
+      def self.from_include_args(included)
+        new(Parsing.include_args_to_hash(included))
+      end
+
+      # @param [Hash] hash
+      def initialize(hash = {})
+        @hash = hash
+      end
+
+      def key?(key)
+        @hash.key?(key) || @hash.key?(:*) || @hash.key?(:**)
+      end
+
+      def [](key)
+        # TODO(beauby): Adopt a lazy caching strategy for generating subtrees.
+        case
+        when @hash.key?(key)
+          self.class.new(@hash[key])
+        when @hash.key?(:*)
+          self.class.new(@hash[:*])
+        when @hash.key?(:**)
+          self.class.new(:** => {})
+        end
+      end
+    end
+  end
+end
diff --git a/lib/active_model/serializer/utils.rb b/lib/active_model/serializer/utils.rb
deleted file mode 100644
index ca54f420..00000000
--- a/lib/active_model/serializer/utils.rb
+++ /dev/null
@@ -1,35 +0,0 @@
-module ActiveModel::Serializer::Utils
-  module_function
-
-  # Translates a comma separated list of dot separated paths (JSON API format) into a Hash.
-  # Example: `'posts.author, posts.comments.upvotes, posts.comments.author'` would become `{ posts: { author: {}, comments: { author: {}, upvotes: {} } } }`.
-  #
-  # @param [String] included
-  # @return [Hash] a Hash representing the same tree structure
-  def include_string_to_hash(included)
-    included.delete(' ').split(',').inject({}) do |hash, path|
-      hash.deep_merge!(path.split('.').reverse_each.inject({}) { |a, e| { e.to_sym => a } })
-    end
-  end
-
-  # Translates the arguments passed to the include option into a Hash. The format can be either
-  # a String (see #include_string_to_hash), an Array of Symbols and Hashes, or a mix of both.
-  # Example: `posts: [:author, comments: [:author, :upvotes]]` would become `{ posts: { author: {}, comments: { author: {}, upvotes: {} } } }`.
-  #
-  # @param [Symbol, Hash, Array, String] included
-  # @return [Hash] a Hash representing the same tree structure
-  def include_args_to_hash(included)
-    case included
-    when Symbol
-      { included => {} }
-    when Hash
-      included.each_with_object({}) { |(key, value), hash| hash[key] = include_args_to_hash(value) }
-    when Array
-      included.inject({}) { |a, e| a.merge!(include_args_to_hash(e)) }
-    when String
-      include_string_to_hash(included)
-    else
-      {}
-    end
-  end
-end
diff --git a/test/action_controller/json_api/linked_test.rb b/test/action_controller/json_api/linked_test.rb
index ba317e21..04ea4c99 100644
--- a/test/action_controller/json_api/linked_test.rb
+++ b/test/action_controller/json_api/linked_test.rb
@@ -51,9 +51,9 @@ module ActionController
             render json: @post, include: [comments: [:author]], adapter: :json_api
           end
 
-          def render_resource_with_nested_has_many_include
+          def render_resource_with_nested_has_many_include_wildcard
             setup_post
-            render json: @post, include: 'author.roles', adapter: :json_api
+            render json: @post, include: 'author.*', adapter: :json_api
           end
 
           def render_resource_with_missing_nested_has_many_include
@@ -96,7 +96,7 @@ module ActionController
         end
 
         def test_render_resource_with_nested_has_many_include
-          get :render_resource_with_nested_has_many_include
+          get :render_resource_with_nested_has_many_include_wildcard
           response = JSON.parse(@response.body)
           expected_linked = [
             {
diff --git a/test/include_tree/from_include_args_test.rb b/test/include_tree/from_include_args_test.rb
new file mode 100644
index 00000000..e8eb01a8
--- /dev/null
+++ b/test/include_tree/from_include_args_test.rb
@@ -0,0 +1,26 @@
+require 'test_helper'
+
+module ActiveModel
+  class Serializer
+    class IncludeTree
+      class FromStringTest < Minitest::Test
+        def test_simple_array
+          input = [:comments, :author]
+          actual = ActiveModel::Serializer::IncludeTree.from_include_args(input)
+          assert(actual.key?(:author))
+          assert(actual.key?(:comments))
+        end
+
+        def test_nested_array
+          input = [:comments, posts: [:author, comments: [:author]]]
+          actual = ActiveModel::Serializer::IncludeTree.from_include_args(input)
+          assert(actual.key?(:posts))
+          assert(actual[:posts].key?(:author))
+          assert(actual[:posts].key?(:comments))
+          assert(actual[:posts][:comments].key?(:author))
+          assert(actual.key?(:comments))
+        end
+      end
+    end
+  end
+end
diff --git a/test/include_tree/from_string_test.rb b/test/include_tree/from_string_test.rb
new file mode 100644
index 00000000..3468cd57
--- /dev/null
+++ b/test/include_tree/from_string_test.rb
@@ -0,0 +1,94 @@
+require 'test_helper'
+
+module ActiveModel
+  class Serializer
+    class IncludeTree
+      class FromStringTest < Minitest::Test
+        def test_single_string
+          input = 'author'
+          actual = ActiveModel::Serializer::IncludeTree.from_string(input)
+          assert(actual.key?(:author))
+        end
+
+        def test_multiple_strings
+          input = 'author,comments'
+          actual = ActiveModel::Serializer::IncludeTree.from_string(input)
+          assert(actual.key?(:author))
+          assert(actual.key?(:comments))
+        end
+
+        def test_multiple_strings_with_space
+          input = 'author, comments'
+          actual = ActiveModel::Serializer::IncludeTree.from_string(input)
+          assert(actual.key?(:author))
+          assert(actual.key?(:comments))
+        end
+
+        def test_nested_string
+          input = 'posts.author'
+          actual = ActiveModel::Serializer::IncludeTree.from_string(input)
+          assert(actual.key?(:posts))
+          assert(actual[:posts].key?(:author))
+        end
+
+        def test_multiple_nested_string
+          input = 'posts.author,posts.comments.author,comments'
+          actual = ActiveModel::Serializer::IncludeTree.from_string(input)
+          assert(actual.key?(:posts))
+          assert(actual[:posts].key?(:author))
+          assert(actual[:posts].key?(:comments))
+          assert(actual[:posts][:comments].key?(:author))
+          assert(actual.key?(:comments))
+        end
+
+        def test_toplevel_star_string
+          input = '*'
+          actual = ActiveModel::Serializer::IncludeTree.from_string(input)
+          assert(actual.key?(:comments))
+        end
+
+        def test_nested_star_string
+          input = 'posts.*'
+          actual = ActiveModel::Serializer::IncludeTree.from_string(input)
+          assert(actual.key?(:posts))
+          assert(actual[:posts].key?(:comments))
+        end
+
+        def test_nested_star_middle_string
+          input = 'posts.*.author'
+          actual = ActiveModel::Serializer::IncludeTree.from_string(input)
+          assert(actual.key?(:posts))
+          assert(actual[:posts].key?(:comments))
+          assert(actual[:posts][:comments].key?(:author))
+          refute(actual[:posts][:comments].key?(:unspecified))
+        end
+
+        def test_nested_star_lower_precedence_string
+          input = 'posts.comments.author,posts.*'
+          actual = ActiveModel::Serializer::IncludeTree.from_string(input)
+          assert(actual.key?(:posts))
+          assert(actual[:posts].key?(:comments))
+          assert(actual[:posts][:comments].key?(:author))
+        end
+
+        def test_toplevel_double_star_string
+          input = '**'
+          actual = ActiveModel::Serializer::IncludeTree.from_string(input)
+          assert(actual.key?(:posts))
+          assert(actual[:posts].key?(:comments))
+          assert(actual[:posts][:comments].key?(:posts))
+        end
+
+        def test_nested_double_star_string
+          input = 'comments, posts.**'
+          actual = ActiveModel::Serializer::IncludeTree.from_string(input)
+          assert(actual.key?(:comments))
+          refute(actual[:comments].key?(:author))
+          assert(actual.key?(:posts))
+          assert(actual[:posts].key?(:comments))
+          assert(actual[:posts][:comments].key?(:posts))
+        end
+      end
+    end
+  end
+end
diff --git a/test/utils/include_args_to_hash_test.rb b/test/utils/include_args_to_hash_test.rb
deleted file mode 100644
index deb87f1c..00000000
--- a/test/utils/include_args_to_hash_test.rb
+++ /dev/null
@@ -1,79 +0,0 @@
-require 'test_helper'
-
-module ActiveModel
-  class Serializer
-    module Utils
-      class IncludeArgsToHashTest < Minitest::Test
-        def test_nil
-          input = nil
-          expected = {}
-          actual = ActiveModel::Serializer::Utils.include_args_to_hash(input)
-          assert_equal(expected, actual)
-        end
-
-        def test_empty_string
-          input = ''
-          expected = {}
-          actual = ActiveModel::Serializer::Utils.include_args_to_hash(input)
-          assert_equal(expected, actual)
-        end
-
-        def test_single_string
-          input = 'author'
-          expected = { author: {} }
-          actual = ActiveModel::Serializer::Utils.include_args_to_hash(input)
-          assert_equal(expected, actual)
-        end
-
-        def test_multiple_strings
-          input = 'author,comments'
-          expected = { author: {}, comments: {} }
-          actual = ActiveModel::Serializer::Utils.include_args_to_hash(input)
-          assert_equal(expected, actual)
-        end
-
-        def test_multiple_strings_with_space
-          input = 'author, comments'
-          expected = { author: {}, comments: {} }
-          actual = ActiveModel::Serializer::Utils.include_args_to_hash(input)
-          assert_equal(expected, actual)
-        end
-
-        def test_nested_string
-          input = 'posts.author'
-          expected = { posts: { author: {} } }
-          actual = ActiveModel::Serializer::Utils.include_args_to_hash(input)
-          assert_equal(expected, actual)
-        end
-
-        def test_multiple_nested_string
-          input = 'posts.author,posts.comments.author,comments'
-          expected = { posts: { author: {}, comments: { author: {} } }, comments: {} }
-          actual = ActiveModel::Serializer::Utils.include_args_to_hash(input)
-          assert_equal(expected, actual)
-        end
-
-        def test_empty_array
-          input = []
-          expected = {}
-          actual = ActiveModel::Serializer::Utils.include_args_to_hash(input)
-          assert_equal(expected, actual)
-        end
-
-        def test_simple_array
-          input = [:comments, :author]
-          expected = { author: {}, comments: {} }
-          actual = ActiveModel::Serializer::Utils.include_args_to_hash(input)
-          assert_equal(expected, actual)
-        end
-
-        def test_nested_array
-          input = [:comments, posts: [:author, comments: [:author]]]
-          expected = { posts: { author: {}, comments: { author: {} } }, comments: {} }
-          actual = ActiveModel::Serializer::Utils.include_args_to_hash(input)
-          assert_equal(expected, actual)
-        end
-      end
-    end
-  end
-end