Pass `connection` rather than `alias_tracker`

After the refactorings we're only using the connection and not the alias
tracker anymore. This builds on commit 18019.

Reuse the already available `@connection` to reduce the surface area of
the alias tracker's API. We can then remove the `attr_reader` because
the connection is already available.

2 files changed, 7 insertions, 7 deletions

diff --git a/activerecord/lib/active_record/associations/alias_tracker.rb b/activerecord/lib/active_record/associations/alias_tracker.rb
index f9c9f8afda..27d918696a 100644
--- a/activerecord/lib/active_record/associations/alias_tracker.rb
+++ b/activerecord/lib/active_record/associations/alias_tracker.rb
@@ -5,7 +5,7 @@ module ActiveRecord
     # Keeps track of table aliases for ActiveRecord::Associations::ClassMethods::JoinDependency and
     # ActiveRecord::Associations::ThroughAssociationScope
     class AliasTracker # :nodoc:
-      attr_reader :aliases, :connection
+      attr_reader :aliases
 
       def self.empty(connection)
         new connection, Hash.new(0)
@@ -63,7 +63,7 @@ module ActiveRecord
           Arel::Table.new(table_name, table_options)
         else
           # Otherwise, we need to use an alias
-          aliased_name = connection.table_alias_for(aliased_name)
+          aliased_name = @connection.table_alias_for(aliased_name)
 
           # Update the count
           aliases[aliased_name] += 1
@@ -80,7 +80,7 @@ module ActiveRecord
       private
 
         def truncate(name)
-          name.slice(0, connection.table_alias_length - 2)
+          name.slice(0, @connection.table_alias_length - 2)
         end
     end
   end
diff --git a/activerecord/lib/active_record/associations/association_scope.rb b/activerecord/lib/active_record/associations/association_scope.rb
index 0fdb3737fd..198a047e18 100644
--- a/activerecord/lib/active_record/associations/association_scope.rb
+++ b/activerecord/lib/active_record/associations/association_scope.rb
@@ -37,7 +37,7 @@ module ActiveRecord
         chain_head, chain_tail = get_chain(reflection, association, alias_tracker)
 
         scope.extending! Array(reflection.options[:extend])
-        add_constraints(scope, owner, klass, reflection, alias_tracker, chain_head, chain_tail)
+        add_constraints(scope, owner, klass, reflection, connection, chain_head, chain_tail)
       end
 
       def join_type
@@ -139,10 +139,10 @@ module ActiveRecord
         [runtime_reflection, prev]
       end
 
-      def add_constraints(scope, owner, assoc_klass, refl, tracker, chain_head, chain_tail)
+      def add_constraints(scope, owner, assoc_klass, refl, connection, chain_head, chain_tail)
         owner_reflection = chain_tail
         table = owner_reflection.alias_name
-        scope = last_chain_scope(scope, table, owner_reflection, owner, tracker, assoc_klass)
+        scope = last_chain_scope(scope, table, owner_reflection, owner, connection, assoc_klass)
 
         reflection = chain_head
         loop do
@@ -152,7 +152,7 @@ module ActiveRecord
           unless reflection == chain_tail
             next_reflection = reflection.next
             foreign_table = next_reflection.alias_name
-            scope = next_chain_scope(scope, table, reflection, tracker, assoc_klass, foreign_table, next_reflection)
+            scope = next_chain_scope(scope, table, reflection, connection, assoc_klass, foreign_table, next_reflection)
           end
 
           # Exclude the scope of the association itself, because that