Revert "Merge pull request #53484 from zzak/query_cache-config-disable"

This reverts commit e60b786.

activerecord/CHANGELOG.md

@@ -1,11 +1,5 @@
 ## Rails 7.1.5 (October 30, 2024) ##
 
-*   Fix support for `query_cache: false` in `database.yml`.
-
-    `query_cache: false` would no longer entirely disable the Active Record query cache.
-
-    *zzak*
-
 *   Fix marshalling of unsaved associated records in 7.1 format.
 
     The 7.1 format would only marshal associated records if the association was loaded.

activerecord/lib/active_record/query_cache.rb

@@ -26,10 +26,7 @@ def uncached(&block)
     end
 
     def self.run
-      ActiveRecord::Base.connection_handler.each_connection_pool.reject(&:query_cache_enabled).each do |pool|
-        next if pool.db_config&.query_cache == false
-        pool.enable_query_cache!
-      end
+      ActiveRecord::Base.connection_handler.each_connection_pool.reject { |p| p.query_cache_enabled }.each { |p| p.enable_query_cache! }
     end
 
     def self.complete(pools)

activerecord/test/cases/query_cache_test.rb

@@ -123,79 +123,6 @@ def test_query_cache_is_applied_to_all_connections
     clean_up_connection_handler
   end
 
-  def test_cache_is_not_applied_when_config_is_false
-    ActiveRecord::Base.connected_to(role: :reading) do
-      db_config = ActiveRecord::Base.configurations.configs_for(env_name: "arunit", name: "primary")
-      ActiveRecord::Base.establish_connection(db_config.configuration_hash.merge(query_cache: false))
-    end
-
-    mw = middleware { |env|
-      ActiveRecord::Base.connection_handler.connection_pool_list(:reading).each do |pool|
-        assert_not_predicate pool.lease_connection, :query_cache_enabled
-        assert_nil pool.query_cache.instance_variable_get(:@max_size)
-      end
-    }
-
-    mw.call({})
-  ensure
-    clean_up_connection_handler
-  end
-
-  def test_cache_is_applied_when_config_is_string
-    ActiveRecord::Base.connected_to(role: :reading) do
-      db_config = ActiveRecord::Base.configurations.configs_for(env_name: "arunit", name: "primary")
-      ActiveRecord::Base.establish_connection(db_config.configuration_hash.merge(query_cache: "unlimited"))
-    end
-
-    mw = middleware { |env|
-      ActiveRecord::Base.connection_handler.connection_pool_list(:reading).each do |pool|
-        assert_predicate pool.lease_connection, :query_cache_enabled
-        assert_nil pool.query_cache.instance_variable_get(:@max_size)
-      end
-    }
-
-    mw.call({})
-  ensure
-    clean_up_connection_handler
-  end
-
-  def test_cache_is_applied_when_config_is_integer
-    ActiveRecord::Base.connected_to(role: :reading) do
-      db_config = ActiveRecord::Base.configurations.configs_for(env_name: "arunit", name: "primary")
-      ActiveRecord::Base.establish_connection(db_config.configuration_hash.merge(query_cache: 42))
-    end
-
-    mw = middleware { |env|
-      ActiveRecord::Base.connection_handler.connection_pool_list(:reading).each do |pool|
-        assert_predicate pool.lease_connection, :query_cache_enabled
-        assert_equal 42, pool.query_cache.instance_variable_get(:@max_size)
-      end
-    }
-
-    mw.call({})
-  ensure
-    clean_up_connection_handler
-  end
-
-  def test_cache_is_applied_when_config_is_nil
-    ActiveRecord::Base.connected_to(role: :reading) do
-      db_config = ActiveRecord::Base.configurations.configs_for(env_name: "arunit", name: "primary")
-      ActiveRecord::Base.establish_connection(db_config.configuration_hash.merge(query_cache: nil))
-    end
-
-    mw = middleware { |env|
-      ActiveRecord::Base.connection_handler.connection_pool_list(:reading).each do |pool|
-        assert_predicate pool.lease_connection, :query_cache_enabled
-      end
-    }
-
-    mw.call({})
-  ensure
-    clean_up_connection_handler
-  end
-
-
-
   if Process.respond_to?(:fork) && !in_memory_db?
     def test_query_cache_with_forked_processes
       ActiveRecord::Base.connected_to(role: :reading) do