Fix tests with counter cache touching and more.

* Refactor to use `touch_updates`

  Ensures we only call `current_time_from_proper_timezone` from one place.

* Clarify touch default in tests.

  Not interested in what happens when passed false but that
  nothing passed means no touching.

* Backdate touched columns in tests.

  We can't be sure a test progresses through time, so our
  touching code may be working correctly but the test
  itself is brittle.

  Fix by backdating that's further in the past akin to
  what the timestamps tests do:
  https://github.com/rails/rails/blob/d753645d40e925973724e4c3a8617b654da90e41/activerecord/test/cases/timestamp_test.rb#L17

* Expand changelog entry.

  Elaborate and show examples.

Closes #26995.

[ Jarred Trost & Kasper Timm Hansen ]

1 files changed, 10 insertions, 18 deletions

diff --git a/activerecord/lib/active_record/counter_cache.rb b/activerecord/lib/active_record/counter_cache.rb
index af29b4c5bb..9355a2f7a7 100644
--- a/activerecord/lib/active_record/counter_cache.rb
+++ b/activerecord/lib/active_record/counter_cache.rb
@@ -47,12 +47,9 @@ module ActiveRecord
 
           updates = { counter_name.to_sym => object.send(counter_association).count(:all) }
 
-          touch_time = object.send(:current_time_from_proper_timezone)
-          resolve_timestamp_columns(object, touch).each do |column|
-            updates[column] = touch_time
-          end
-
-          unscoped.where(primary_key => object.id).update_all(updates)
+          unscoped.where(primary_key => object.id).update_all(
+            updates.merge(touch_updates(object, touch))
+          )
         end
         return true
       end
@@ -109,10 +106,7 @@ module ActiveRecord
 
         if touch
           object = find(id)
-          touch_time = object.send(:current_time_from_proper_timezone)
-          timestamps = resolve_timestamp_columns(object, touch)
-
-          timestamps.map do |column|
+          touch_updates(object, touch).map do |column, touch_time|
             updates << "#{connection.quote_column_name(column.to_s)} = #{connection.quote(touch_time)}"
           end
         end
@@ -144,7 +138,7 @@ module ActiveRecord
       #   # and update the updated_at value.
       #   DiscussionBoard.increment_counter(:posts_count, 5, touch: true)
       def increment_counter(counter_name, id, touch: nil)
-        update_counters(id, { counter_name => 1 }.merge(touch: touch))
+        update_counters(id, counter_name => 1, touch: touch)
       end
 
       # Decrement a numeric field by one, via a direct SQL update.
@@ -169,16 +163,14 @@ module ActiveRecord
       #   # and update the updated_at value.
       #   DiscussionBoard.decrement_counter(:posts_count, 5, touch: true)
       def decrement_counter(counter_name, id, touch: nil)
-        update_counters(id, { counter_name => -1 }.merge(touch: touch))
+        update_counters(id, counter_name => -1, touch: touch)
       end
 
       private
-        def resolve_timestamp_columns(object, touch)
-          if touch == true
-            object.send(:timestamp_attributes_for_update_in_model)
-          else
-            Array(touch)
-          end
+        def touch_updates(object, touch)
+          touch = object.send(:timestamp_attributes_for_update_in_model) if touch == true
+          touch_time = object.send(:current_time_from_proper_timezone)
+          Array(touch).map { |column| [ column, touch_time ] }.to_h
         end
     end