Improve disable and disable_tracking, add their inverses

CHANGELOG.md

@@ -4,6 +4,7 @@
 * [#236](https://github.com/mongoid/mongoid-history/pull/236): Fix Ruby 2.7 keyword argument warnings - [@vasilysn](https://github.com/vasilysn).
 * [#237](https://github.com/mongoid/mongoid-history/pull/237): Fix tracking subclasses with additional fields - [@getaroom](https://github.com/getaroom).
 * [#239](https://github.com/mongoid/mongoid-history/pull/239): Optimize `modified_attributes_for_create` 6-7x - [@getaroom](https://github.com/getaroom).
+* [#240](https://github.com/mongoid/mongoid-history/pull/240): `Mongoid::History.disable` and `disable_tracking` now restore the original state if given a block and can be run without a block plus `Mongoid::History.enable` and `enable_tracking` have been added - [@getaroom](https://github.com/getaroom).
 
 ### 0.8.2 (2019/12/02)
 

README.md

@@ -149,11 +149,34 @@ Comment.disable_tracking do
   comment.update_attributes(:title => "Test 3")
 end
 
-# globally disable all history tracking
+# disable tracking for comments by default
+Comment.disable_tracking
+
+# enable tracking for comments within a block
+Comment.enable_tracking do
+  comment.update_attributes(:title => "Test 3")
+end
+
+# renable tracking for comments by default
+Comment.enable_tracking
+
+# globally disable all history tracking within a block
 Mongoid::History.disable do
   comment.update_attributes(:title => "Test 3")
   user.update_attributes(:name => "Eddie Van Halen")
 end
+
+# globally disable all history tracking by default
+Mongoid::History.disable
+
+# globally enable all history tracking within a block
+Mongoid::History.enable do
+  comment.update_attributes(:title => "Test 3")
+  user.update_attributes(:name => "Eddie Van Halen")
+end
+
+# globally renable all history tracking by default
+Mongoid::History.enable
 ```
 
 You may want to track changes on all fields.

lib/mongoid/history.rb

@@ -19,11 +19,20 @@ class << self
       attr_accessor :modifier_class_name
       attr_accessor :current_user_method
 
-      def disable(&_block)
+      def disable
+        original_flag = store[GLOBAL_TRACK_HISTORY_FLAG]
         store[GLOBAL_TRACK_HISTORY_FLAG] = false
-        yield
+        yield if block_given?
       ensure
+        store[GLOBAL_TRACK_HISTORY_FLAG] = original_flag if block_given?
+      end
+
+      def enable
+        original_flag = store[GLOBAL_TRACK_HISTORY_FLAG]
         store[GLOBAL_TRACK_HISTORY_FLAG] = true
+        yield if block_given?
+      ensure
+        store[GLOBAL_TRACK_HISTORY_FLAG] = original_flag if block_given?
       end
 
       def enabled?

lib/mongoid/history/trackable.rb

@@ -52,11 +52,20 @@ def dynamic_enabled?
           Mongoid::Compatibility::Version.mongoid3? || (self < Mongoid::Attributes::Dynamic).present?
         end
 
-        def disable_tracking(&_block)
+        def disable_tracking
+          original_flag = Mongoid::History.store[track_history_flag]
           Mongoid::History.store[track_history_flag] = false
-          yield
+          yield if block_given?
         ensure
+          Mongoid::History.store[track_history_flag] = original_flag if block_given?
+        end
+
+        def enable_tracking
+          original_flag = Mongoid::History.store[track_history_flag]
           Mongoid::History.store[track_history_flag] = true
+          yield if block_given?
+        ensure
+          Mongoid::History.store[track_history_flag] = original_flag if block_given?
         end
 
         def track_history_flag

spec/unit/trackable_spec.rb

@@ -270,6 +270,11 @@ class MySubModel < MyModel
 
     describe '#track_history?' do
       shared_examples_for 'history tracking' do
+        after do
+          Mongoid::History.store[Mongoid::History::GLOBAL_TRACK_HISTORY_FLAG] = true
+          Mongoid::History.store[MyModel.track_history_flag] = true
+        end
+
         context 'when tracking is globally enabled' do
           it 'should be enabled on the current thread' do
             expect(Mongoid::History.enabled?).to eq(true)
@@ -283,7 +288,40 @@ class MySubModel < MyModel
             end
           end
 
-          it 'should be rescued if an exception occurs' do
+          it 'should be enabled within enable_tracking' do
+            MyModel.disable_tracking do
+              MyModel.enable_tracking do
+                expect(Mongoid::History.enabled?).to eq(true)
+                expect(MyModel.new.track_history?).to eq(true)
+              end
+            end
+          end
+
+          it 'should still be disabled after completing a nested disable_tracking' do
+            MyModel.disable_tracking do
+              MyModel.disable_tracking {}
+              expect(Mongoid::History.enabled?).to eq(true)
+              expect(MyModel.new.track_history?).to eq(false)
+            end
+          end
+
+          it 'should still be enabled after completing a nested enable_tracking' do
+            MyModel.enable_tracking do
+              MyModel.enable_tracking {}
+              expect(Mongoid::History.enabled?).to eq(true)
+              expect(MyModel.new.track_history?).to eq(true)
+            end
+          end
+
+          it 'should restore the original state after completing enable_tracking' do
+            MyModel.disable_tracking do
+              MyModel.enable_tracking {}
+              expect(Mongoid::History.enabled?).to eq(true)
+              expect(MyModel.new.track_history?).to eq(false)
+            end
+          end
+
+          it 'should be rescued if an exception occurs in disable_tracking' do
             begin
               MyModel.disable_tracking do
                 raise 'exception'
@@ -294,6 +332,33 @@ class MySubModel < MyModel
             expect(MyModel.new.track_history?).to eq(true)
           end
 
+          it 'should be rescued if an exception occurs in enable_tracking' do
+            MyModel.disable_tracking do
+              begin
+                MyModel.enable_tracking do
+                  raise 'exception'
+                end
+              rescue
+              end
+              expect(Mongoid::History.enabled?).to eq(true)
+              expect(MyModel.new.track_history?).to eq(false)
+            end
+          end
+
+          it 'should stay disabled if disable_tracking called without a block' do
+            MyModel.disable_tracking
+            expect(Mongoid::History.enabled?).to eq(true)
+            expect(MyModel.new.track_history?).to eq(false)
+          end
+
+          it 'should stay enabled if enable_tracking called without a block' do
+            MyModel.disable_tracking do
+              MyModel.enable_tracking
+              expect(Mongoid::History.enabled?).to eq(true)
+              expect(MyModel.new.track_history?).to eq(true)
+            end
+          end
+
           context 'with multiple classes' do
             before :each do
               class MyModel2
@@ -317,14 +382,49 @@ class MyModel2
           end
         end
 
-        context 'when tracking is globally disabled' do
+        context 'when changing global tracking' do
           it 'should be disabled by the global disablement' do
             Mongoid::History.disable do
               expect(Mongoid::History.enabled?).to eq(false)
               expect(MyModel.new.track_history?).to eq(false)
             end
           end
 
+          it 'should be enabled by the global enablement' do
+            Mongoid::History.disable do
+              Mongoid::History.enable do
+                expect(Mongoid::History.enabled?).to eq(true)
+                expect(MyModel.new.track_history?).to eq(true)
+              end
+            end
+          end
+
+          it 'should restore the original state after completing enable' do
+            Mongoid::History.disable do
+              Mongoid::History.enable {}
+              expect(Mongoid::History.enabled?).to eq(false)
+              expect(MyModel.new.track_history?).to eq(false)
+            end
+          end
+
+          it 'should still be disabled after completing a nested disable' do
+            Mongoid::History.disable do
+              Mongoid::History.disable {}
+              expect(Mongoid::History.enabled?).to eq(false)
+              expect(MyModel.new.track_history?).to eq(false)
+            end
+          end
+
+          it 'should still be enabled after completing a nested enable' do
+            Mongoid::History.disable do
+              Mongoid::History.enable do
+                Mongoid::History.enable {}
+                expect(Mongoid::History.enabled?).to eq(true)
+                expect(MyModel.new.track_history?).to eq(true)
+              end
+            end
+          end
+
           it 'should be disabled within disable_tracking' do
             Mongoid::History.disable do
               MyModel.disable_tracking do
@@ -334,7 +434,7 @@ class MyModel2
             end
           end
 
-          it 'should be rescued if an exception occurs' do
+          it 'should be rescued if an exception occurs in disable' do
             Mongoid::History.disable do
               begin
                 MyModel.disable_tracking do
@@ -347,6 +447,33 @@ class MyModel2
             end
           end
 
+          it 'should be rescued if an exception occurs in enable' do
+            Mongoid::History.disable do
+              begin
+                Mongoid::History.enable do
+                  raise 'exception'
+                end
+              rescue
+              end
+              expect(Mongoid::History.enabled?).to eq(false)
+              expect(MyModel.new.track_history?).to eq(false)
+            end
+          end
+
+          it 'should stay disabled if disable called without a block' do
+            Mongoid::History.disable
+            expect(Mongoid::History.enabled?).to eq(false)
+            expect(MyModel.new.track_history?).to eq(false)
+          end
+
+          it 'should stay enabled if enable called without a block' do
+            Mongoid::History.disable do
+              Mongoid::History.enable
+              expect(Mongoid::History.enabled?).to eq(true)
+              expect(MyModel.new.track_history?).to eq(true)
+            end
+          end
+
           context 'with multiple classes' do
             before :each do
               class MyModel2
@@ -361,7 +488,7 @@ class MyModel2
               Object.send(:remove_const, :MyModel2)
             end
 
-            it 'should be disabled only for the class that calls disable_tracking' do
+            it 'should be disabled for all classes' do
               Mongoid::History.disable do
                 MyModel.disable_tracking do
                   expect(Mongoid::History.enabled?).to eq(false)