Remove deprecated Document#as_json hack (#5755)

Co-authored-by: Jamis Buck <jamis.buck@mongodb.com>

Author: johnnyshields

docs/release-notes/mongoid-9.0.txt

@@ -154,11 +154,16 @@ prior has been dropped (you must use a minimum of version 8.0.)
 Deprecated functionality removed
 --------------------------------
 
+**Breaking change:** The following deprecated functionality is now removed:
+
 - The ``Mongoid::QueryCache`` module has been removed. Please replace any usages 1-for-1 with ``Mongo::QueryCache``.
   The method ``Mongoid::QueryCache#clear_cache`` should be replaced with ``Mongo::QueryCache#clear``.
   All other methods and submodules are identically named. Refer to the `driver query cache documentation
   <https://mongodb.com/docs/ruby-driver/current/reference/query-cache/>`_ for more details.
 - ``Object#blank_criteria?`` method is removed (was previously deprecated.)
+- ``Document#as_json :compact`` option is removed. Please call ```#compact`` on the
+  returned ``Hash`` object instead.
+- The deprecated class ``Mongoid::Errors::InvalidStorageParent`` has been removed.
 
 
 ``touch`` method now clears changed state

lib/mongoid/document.rb

@@ -135,33 +135,6 @@ def as_document
       BSON::Document.new(as_attributes)
     end
 
-    # Calls #as_json on the document with additional, Mongoid-specific options.
-    #
-    # @note Rails 6 changes return value of as_json for non-primitive types
-    #   such as BSON::ObjectId. In Rails <= 5, as_json returned these as
-    #   instances of the class. In Rails 6, these are returned serialized to
-    #   primitive types (e.g. {'$oid'=>'5bcfc40bde340b37feda98e9'}).
-    #   See https://github.com/rails/rails/commit/2e5cb980a448e7f4ab00df6e9ad4c1cc456616aa
-    #   for more information.
-    #
-    # @example Get the document as json.
-    #   document.as_json(compact: true)
-    #
-    # @param [ Hash ] options The options.
-    #
-    # @option options [ true | false ] :compact (Deprecated) Whether to include fields
-    #   with nil values in the json document.
-    #
-    # @return [ Hash ] The document as json.
-    def as_json(options = nil)
-      rv = super
-      if options && options[:compact]
-        Mongoid::Warnings.warn_as_json_compact_deprecated
-        rv = rv.compact
-      end
-      rv
-    end
-
     # Returns an instance of the specified class with the attributes,
     # errors, and embedded documents of the current document.
     #

lib/mongoid/warnings.rb

@@ -30,7 +30,6 @@ def warning(id, message)
     end
 
     warning :geo_haystack_deprecated, 'The geoHaystack type is deprecated.'
-    warning :as_json_compact_deprecated, '#as_json :compact option is deprecated. Please call #compact on the returned Hash object instead.'
     warning :symbol_type_deprecated, 'The BSON Symbol type is deprecated by MongoDB. Please use String or StringifiedSymbol field types instead of the Symbol field type.'
     warning :legacy_readonly, 'The readonly! method will only mark the document readonly when the legacy_readonly feature flag is switched off.'
     warning :mutable_ids, 'Ignoring updates to immutable attribute `_id`. Please set Mongoid::Config.immutable_ids to true and update your code so that `_id` is never updated.'

spec/mongoid/criteria_spec.rb

@@ -288,7 +288,6 @@
       Band.where(name: "Depeche Mode")
     end
 
-
     it "returns the criteria as a json hash" do
       expect(criteria.as_json).to eq([ band.serializable_hash.as_json ])
     end

spec/mongoid/document_spec.rb

@@ -429,35 +429,6 @@ class << self; attr_accessor :name; end
         end
       end
     end
-
-    context "when the Mongoid-specific options are provided" do
-
-      let(:options) do
-        { compact: true }
-      end
-
-      it "applies the Mongoid-specific options" do
-        expect(person.as_json(options)["title"]).to eq("Sir")
-        expect(person.as_json(options)["age"]).to eq(100)
-        expect(person.as_json(options).keys).not_to include("lunch_time")
-      end
-
-      context "when options for the super method are provided" do
-
-        let(:options) do
-          { compact: true, only: [:title, :pets, :ssn] }
-        end
-
-        it "passes the options through to the super method" do
-          expect(person.as_json(options)["title"]).to eq("Sir")
-          expect(person.as_json(options)["pets"]).to eq(false)
-        end
-
-        it "applies the Mongoid-specific options" do
-          expect(person.as_json(options).keys).not_to include("ssn")
-        end
-      end
-    end
   end
 
   describe "#as_document" do