change AMS::JSON.include_root_in_json default value to false

Changes:

* Update `include_root_in_json` default value to false for default value
  to false for `ActiveModel::Serializers::JSON`.
* Remove unnecessary change to include_root_in_json option in
  wrap_parameters template.
* Update `as_json` documentation.
* Fix JSONSerialization tests.

Problem:

It's confusing that AM serializers behave differently from AR,
even when AR objects include AM serializers module.

    class User < ActiveRecord::Base; end

    class Person
      include ActiveModel::Model
      include ActiveModel::AttributeMethods
      include ActiveModel::Serializers::JSON

      attr_accessor :name, :age

      def attributes
        instance_values
      end
    end

    user.as_json
    => {"id"=>1, "name"=>"Konata Izumi", "age"=>16, "awesome"=>true}
    # root is not included

    person.as_json
    => {"person"=>{"name"=>"Francesco", "age"=>22}}
    # root is included

    ActiveRecord::Base.include_root_in_json
    => false

    Person.include_root_in_json
    => true

    # different default values for include_root_in_json

Proposal:

Change the default value of AM serializers to false, update
the misleading documentation and remove unnecessary change
to false of include_root_in_json option with AR objects.

    class User < ActiveRecord::Base; end

    class Person
      include ActiveModel::Model
      include ActiveModel::AttributeMethods
      include ActiveModel::Serializers::JSON

      attr_accessor :name, :age

      def attributes
        instance_values
      end
    end

    user.as_json
    => {"id"=>1, "name"=>"Konata Izumi", "age"=>16, "awesome"=>true}
    # root is not included

    person.as_json
    => {"name"=>"Francesco", "age"=>22}
    # root is not included

    ActiveRecord::Base.include_root_in_json
    => false

    Person.include_root_in_json
    => false

    # same behaviour, more consistent

Fixes #6578.

1 files changed, 44 insertions, 44 deletions

diff --git a/activemodel/lib/active_model/serializers/json.rb b/activemodel/lib/active_model/serializers/json.rb
index 63ab8e7edc..e668b4a009 100644
--- a/activemodel/lib/active_model/serializers/json.rb
+++ b/activemodel/lib/active_model/serializers/json.rb
@@ -13,80 +13,80 @@ module ActiveModel
         extend ActiveModel::Configuration
 
         config_attribute :include_root_in_json
-        self.include_root_in_json = true
+        self.include_root_in_json = false
       end
 
       # Returns a hash representing the model. Some configuration can be
       # passed through +options+.
       #
       # The option <tt>include_root_in_json</tt> controls the top-level behavior
-      # of +as_json+. If true (the default) +as_json+ will emit a single root
-      # node named after the object's type. For example:
+      # of +as_json+. If true +as_json+ will emit a single root node named after
+      # the object's type. The default value for <tt>include_root_in_json</tt>
+      # option is +false+.
       #
       #   user = User.find(1)
       #   user.as_json
-      #   # => { "user": {"id": 1, "name": "Konata Izumi", "age": 16,
-      #                   "created_at": "2006/08/01", "awesome": true} }
+      #   # => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
+      #   #     "created_at" => "2006/08/01", "awesome" => true}
+      #
+      #   ActiveRecord::Base.include_root_in_json = true
       #
-      #   ActiveRecord::Base.include_root_in_json = false
       #   user.as_json
-      #   # => {"id": 1, "name": "Konata Izumi", "age": 16,
-      #         "created_at": "2006/08/01", "awesome": true}
+      #   # => { "user" => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
+      #   #                  "created_at" => "2006/08/01", "awesome" => true } }
       #
-      # This behavior can also be achieved by setting the <tt>:root</tt> option to +false+ as in:
+      # This behavior can also be achieved by setting the <tt>:root</tt> option
+      # to +true+ as in:
       #
       #   user = User.find(1)
-      #   user.as_json(root: false)
-      #   # =>  {"id": 1, "name": "Konata Izumi", "age": 16,
-      #          "created_at": "2006/08/01", "awesome": true}
-      #
-      # The remainder of the examples in this section assume include_root_in_json is set to
-      # <tt>false</tt>.
+      #   user.as_json(root: true)
+      #   # => { "user" => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
+      #   #                  "created_at" => "2006/08/01", "awesome" => true } }
       #
       # Without any +options+, the returned Hash will include all the model's
-      # attributes. For example:
+      # attributes.
       #
       #   user = User.find(1)
       #   user.as_json
-      #   # => {"id": 1, "name": "Konata Izumi", "age": 16,
-      #         "created_at": "2006/08/01", "awesome": true}
+      #   # => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
+      #   #      "created_at" => "2006/08/01", "awesome" => true}
       #
-      # The <tt>:only</tt> and <tt>:except</tt> options can be used to limit the attributes
-      # included, and work similar to the +attributes+ method. For example:
+      # The <tt>:only</tt> and <tt>:except</tt> options can be used to limit
+      # the attributes included, and work similar to the +attributes+ method.
       #
-      #   user.as_json(:only => [ :id, :name ])
-      #   # => {"id": 1, "name": "Konata Izumi"}
+      #   user.as_json(only: [:id, :name])
+      #   # => { "id" => 1, "name" => "Konata Izumi" }
       #
-      #   user.as_json(:except => [ :id, :created_at, :age ])
-      #   # => {"name": "Konata Izumi", "awesome": true}
+      #   user.as_json(except: [:id, :created_at, :age])
+      #   # => { "name" => "Konata Izumi", "awesome" => true }
       #
       # To include the result of some method calls on the model use <tt>:methods</tt>:
       #
-      #   user.as_json(:methods => :permalink)
-      #   # => {"id": 1, "name": "Konata Izumi", "age": 16,
-      #         "created_at": "2006/08/01", "awesome": true,
-      #         "permalink": "1-konata-izumi"}
+      #   user.as_json(methods: :permalink)
+      #   # => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
+      #   #      "created_at" => "2006/08/01", "awesome" => true,
+      #   #      "permalink" => "1-konata-izumi" }
       #
       # To include associations use <tt>:include</tt>:
       #
-      #   user.as_json(:include => :posts)
-      #   # => {"id": 1, "name": "Konata Izumi", "age": 16,
-      #         "created_at": "2006/08/01", "awesome": true,
-      #         "posts": [{"id": 1, "author_id": 1, "title": "Welcome to the weblog"},
-      #                   {"id": 2, author_id: 1, "title": "So I was thinking"}]}
+      #   user.as_json(include: :posts)
+      #   # => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
+      #   #      "created_at" => "2006/08/01", "awesome" => true,
+      #   #      "posts" => [ { "id" => 1, "author_id" => 1, "title" => "Welcome to the weblog" },
+      #   #                   { "id" => 2, "author_id" => 1, "title" => "So I was thinking" } ] }
       #
       # Second level and higher order associations work as well:
       #
-      #   user.as_json(:include => { :posts => {
-      #                                  :include => { :comments => {
-      #                                                :only => :body } },
-      #                                  :only => :title } })
-      #   # => {"id": 1, "name": "Konata Izumi", "age": 16,
-      #         "created_at": "2006/08/01", "awesome": true,
-      #         "posts": [{"comments": [{"body": "1st post!"}, {"body": "Second!"}],
-      #                    "title": "Welcome to the weblog"},
-      #                   {"comments": [{"body": "Don't think too hard"}],
-      #                    "title": "So I was thinking"}]}
+      #   user.as_json(include: { posts: {
+      #                              include: { comments: {
+      #                                             only: :body } },
+      #                              only: :title } })
+      #   # => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
+      #   #      "created_at" => "2006/08/01", "awesome" => true,
+      #   #      "posts" => [ { "comments" => [ { "body" => "1st post!" }, { "body" => "Second!" } ],
+      #   #                     "title" => "Welcome to the weblog" },
+      #   #                   { "comments" => [ { "body" => "Don't think too hard" } ],
+      #   #                     "title" => "So I was thinking" } ] }
       def as_json(options = nil)
         root = include_root_in_json
         root = options[:root] if options.try(:key?, :root)
@@ -106,4 +106,4 @@ module ActiveModel
       end
     end
   end
-end
+end
\ No newline at end of file