MONGOID-4753 Make global Boolean definition opt-in (#4927)

* MONGOID-4753 Make global Boolean definition opt-in

* Add a note about restoring global Boolean

* fix tests

Co-authored-by: Oleg Pudeyev <[email protected]>

docs/tutorials/mongoid-upgrade.txt

@@ -23,6 +23,79 @@ Upgrading to Mongoid 7.3
 
 The following sections describe significant changes in Mongoid 7.3.
 
+``::Boolean`` Removed
+---------------------
+
+**Breaking change:** Mongoid 7.3 removes the global ``::Boolean`` class.
+
+This change should have no impact on classes that simply use ``Boolean``
+fields, as the ``Boolean`` class is aliased from ``Mongoid::Fields``
+(which is included in ``Mongoid::Document``). The following field definition
+continues to work in 7.3 as it did in 7.2:
+
+.. code-block:: ruby
+
+  class User
+    include Mongoid::Document
+
+    field :verified, type: Boolean
+  end
+
+However, code that is not executed in the context of a class including
+``Mongoid::Document`` may need to explicitly qualify ``Boolean`` references.
+The following snippet fails with Mongoid 7.3 due to ``Boolean`` being
+unqualified:
+
+.. code-block:: ruby
+
+  class User
+    include Mongoid::Document
+  end
+
+  User.field :verified, type: Boolean
+
+To fix it, use the fully-qualified ``Mongoid::Boolean`` class:
+
+.. code-block:: ruby
+
+  User.field :verified, type: Mongoid::Boolean
+
+Note that ``class_eval`` is executed in the scope of the caller, not in
+the scope of the class being modified. Thus even when using ``class_eval``
+it is necessary to fully qualify ``Mongoid::Boolean``:
+
+.. code-block:: ruby
+
+  User.class_eval do
+    field :verified, type: Mongoid::Boolean
+  end
+
+Additionally, in Mongoid 7.2 ``::Boolean`` and ``Mongoid::Boolean`` were
+different classes. In Mongoid 7.3 there is only one class which is
+``Mongoid::Boolean``.
+
+It is possible to restore the global ``::Boolean`` class by executing in
+your application:
+
+.. code-block:: ruby
+
+  Boolean = Mongoid::Boolean
+
+Note that this aliases ``Mongoid::Boolean`` to ``::Boolean`` such that there
+is still only a single Boolean class:
+
+.. code-block:: ruby
+
+  # With Mongoid 7.3:
+  Boolean = Mongoid::Boolean
+  Boolean == Mongoid::Boolean
+  # => true
+
+  # With Mongoid 7.2:
+  Boolean == Mongoid::Boolean
+  # => false
+
+
 Selector Key Stringification
 ----------------------------
 

lib/mongoid/criteria/queryable/extensions.rb

@@ -1,10 +1,6 @@
 # frozen_string_literal: true
 # encoding: utf-8
 
-unless defined?(Boolean)
-  class Boolean; end
-end
-
 if defined?(ActiveSupport)
   unless defined?(ActiveSupport::TimeWithZone)
     require "active_support/time_with_zone"

lib/mongoid/criteria/queryable/extensions/boolean.rb

@@ -33,4 +33,4 @@ def evolve(object)
   end
 end
 
-::Boolean.__send__(:extend, Mongoid::Criteria::Queryable::Extensions::Boolean::ClassMethods)
+Mongoid::Boolean.__send__(:extend, Mongoid::Criteria::Queryable::Extensions::Boolean::ClassMethods)

lib/mongoid/criteria/queryable/selectable.rb

@@ -195,11 +195,11 @@ def exists(criterion)
           end
 
           typed_override(criterion, "$exists") do |value|
-            ::Boolean.evolve(value)
+            Mongoid::Boolean.evolve(value)
           end
         end
         key :exists, :override, "$exists" do |value|
-          ::Boolean.evolve(value)
+          Mongoid::Boolean.evolve(value)
         end
 
         # Add a $geoIntersects or $geoWithin selection. Symbol operators must

lib/mongoid/extensions/boolean.rb

@@ -16,9 +16,8 @@ class << self
       #
       # @since 3.0.0
       def mongoize(object)
-        ::Boolean.evolve(object)
+        evolve(object)
       end
-      alias :evolve :mongoize
     end
   end
 end

lib/mongoid/extensions/false_class.rb

@@ -28,7 +28,7 @@ def __sortable__
       #
       # @since 1.0.0
       def is_a?(other)
-        if other == ::Boolean || other.class == ::Boolean
+        if other == Mongoid::Boolean || other.class == Mongoid::Boolean
           return true
         end
         super(other)

lib/mongoid/extensions/true_class.rb

@@ -28,7 +28,7 @@ def __sortable__
       #
       # @since 1.0.0
       def is_a?(other)
-        if other == ::Boolean || other.class == ::Boolean
+        if other == Mongoid::Boolean || other.class == Mongoid::Boolean
           return true
         end
         super(other)

lib/mongoid/fields.rb

@@ -13,6 +13,7 @@ module Fields
     extend ActiveSupport::Concern
 
     StringifiedSymbol = Mongoid::StringifiedSymbol
+    Boolean = Mongoid::Boolean
 
     # For fields defined with symbols use the correct class.
     #

spec/mongoid/criteria/queryable/extensions/boolean_spec.rb

@@ -3,7 +3,7 @@
 
 require "spec_helper"
 
-describe Boolean do
+describe Mongoid::Boolean do
 
   describe ".evolve" do
 

spec/mongoid/extensions/false_class_spec.rb

@@ -17,7 +17,7 @@
     context "when provided a Boolean" do
 
       it "returns true" do
-        expect(false.is_a?(Boolean)).to be true
+        expect(false.is_a?(Mongoid::Boolean)).to be true
       end
     end
 

spec/mongoid/extensions/true_class_spec.rb

@@ -17,7 +17,7 @@
     context "when provided a Boolean" do
 
       it "returns true" do
-        expect(true.is_a?(Boolean)).to be true
+        expect(true.is_a?(Mongoid::Boolean)).to be true
       end
     end
 

spec/mongoid/fields/localized_spec.rb

@@ -448,7 +448,7 @@
         context "when the value is false" do
 
           let(:field) do
-            described_class.new(:boolean_value, localize: true, type: Boolean)
+            described_class.new(:boolean_value, localize: true, type: Mongoid::Boolean)
           end
 
           let(:value) do
@@ -463,7 +463,7 @@
         context "when the value is true" do
 
           let(:field) do
-            described_class.new(:boolean_value, localize: true, type: Boolean)
+            described_class.new(:boolean_value, localize: true, type: Mongoid::Boolean)
           end
 
           let(:value) do
@@ -491,7 +491,7 @@
               end
 
               let(:field) do
-                described_class.new(:boolean_value, localize: true, type: Boolean)
+                described_class.new(:boolean_value, localize: true, type: Mongoid::Boolean)
               end
 
               let(:value) do
@@ -510,7 +510,7 @@
               end
 
               let(:field) do
-                described_class.new(:boolean_value, localize: true, type: Boolean)
+                described_class.new(:boolean_value, localize: true, type: Mongoid::Boolean)
               end
 
               let(:value) do

spec/mongoid/fields_spec.rb

@@ -322,7 +322,7 @@
       end
 
       it "converts to Mongoid::Boolean" do
-        expect(klass.field(:test, type: Boolean).type).to be(Mongoid::Boolean)
+        expect(klass.field(:test, type: Mongoid::Boolean).type).to be(Mongoid::Boolean)
       end
     end
 
@@ -404,7 +404,7 @@
       context "when the options are all standard" do
 
         before do
-          Band.field :acceptable, type: Boolean
+          Band.field :acceptable, type: Mongoid::Boolean
         end
 
         after do
@@ -419,7 +419,7 @@
       context "when a custom option is provided" do
 
         before do
-          Band.field :acceptable, type: Boolean, custom: true
+          Band.field :acceptable, type: Mongoid::Boolean, custom: true
         end
 
         it "adds the field to the model" do
@@ -990,7 +990,7 @@ def testing=(value)
       end
 
       before do
-        Person.field :aliased, as: :alias, type: Boolean, overwrite: true
+        Person.field :aliased, as: :alias, type: Mongoid::Boolean, overwrite: true
       end
 
       it "uses the alias to write the attribute" do