Don't require predicate_builder to create aliased relations

Since it is possible to correctly construct the predicate_builder on the
callee side if model class and aliased table object are passed, this
eliminates the need for users to construct the predicate_builder and
simplifies the creation of aliased relations.

Author: kamipo

activerecord/lib/active_record/core.rb

@@ -370,7 +370,7 @@ def arel_table # :nodoc:
       end
 
       def predicate_builder # :nodoc:
-        @predicate_builder ||= PredicateBuilder.new(table_metadata)
+        @predicate_builder ||= PredicateBuilder.new(TableMetadata.new(self, arel_table))
       end
 
       def type_caster # :nodoc:
@@ -415,10 +415,6 @@ def relation
           end
         end
 
-        def table_metadata
-          TableMetadata.new(self, arel_table)
-        end
-
         def cached_find_by(keys, values)
           with_connection do |connection|
             statement = cached_find_by_statement(connection, keys) { |params|

activerecord/lib/active_record/reflection.rb

@@ -198,7 +198,7 @@ def scopes
       end
 
       def join_scope(table, foreign_table, foreign_klass)
-        predicate_builder = predicate_builder(table)
+        predicate_builder = PredicateBuilder.new(TableMetadata.new(klass, table))
         scope_chain_items = join_scopes(table, predicate_builder)
         klass_scope       = klass_join_scope(table, predicate_builder)
 
@@ -224,15 +224,15 @@ def join_scope(table, foreign_table, foreign_klass)
         klass_scope
       end
 
-      def join_scopes(table, predicate_builder, klass = self.klass, record = nil) # :nodoc:
+      def join_scopes(table, predicate_builder = nil, klass = self.klass, record = nil) # :nodoc:
         if scope
           [scope_for(build_scope(table, predicate_builder, klass), record)]
         else
           []
         end
       end
 
-      def klass_join_scope(table, predicate_builder) # :nodoc:
+      def klass_join_scope(table, predicate_builder = nil) # :nodoc:
         relation = build_scope(table, predicate_builder)
         klass.scope_for_association(relation)
       end
@@ -333,12 +333,8 @@ def chain
         collect_join_chain
       end
 
-      def build_scope(table, predicate_builder = predicate_builder(table), klass = self.klass)
-        Relation.create(
-          klass,
-          table: table,
-          predicate_builder: predicate_builder
-        )
+      def build_scope(table, predicate_builder = nil, klass = self.klass)
+        Relation.create(klass, table:, predicate_builder:)
       end
 
       def strict_loading?
@@ -357,10 +353,6 @@ def actual_source_reflection # FIXME: this is a horrible name
         end
 
       private
-        def predicate_builder(table)
-          PredicateBuilder.new(TableMetadata.new(klass, table))
-        end
-
         def primary_key(klass)
           klass.primary_key || raise(UnknownPrimaryKey.new(klass))
         end
@@ -1070,7 +1062,7 @@ def scopes
         source_reflection.scopes + super
       end
 
-      def join_scopes(table, predicate_builder, klass = self.klass, record = nil) # :nodoc:
+      def join_scopes(table, predicate_builder = nil, klass = self.klass, record = nil) # :nodoc:
         source_reflection.join_scopes(table, predicate_builder, klass, record) + super
       end
 
@@ -1243,7 +1235,7 @@ def initialize(reflection, previous_reflection)
         @previous_reflection = previous_reflection
       end
 
-      def join_scopes(table, predicate_builder, klass = self.klass, record = nil) # :nodoc:
+      def join_scopes(table, predicate_builder = nil, klass = self.klass, record = nil) # :nodoc:
         scopes = @previous_reflection.join_scopes(table, predicate_builder, klass, record) + super
         scopes << build_scope(table, predicate_builder, klass).instance_exec(record, &source_type_scope)
       end

activerecord/lib/active_record/relation.rb

@@ -74,7 +74,14 @@ def exec_explain(&block)
     alias :loaded? :loaded
     alias :locked? :lock_value
 
-    def initialize(model, table: model.arel_table, predicate_builder: model.predicate_builder, values: {})
+    def initialize(model, table: nil, predicate_builder: nil, values: {})
+      if table
+        predicate_builder ||= PredicateBuilder.new(TableMetadata.new(model, table))
+      else
+        table = model.arel_table
+        predicate_builder ||= model.predicate_builder
+      end
+
       @model  = model
       @table  = table
       @values = values

activerecord/test/cases/batches_test.rb

@@ -937,14 +937,8 @@ def test_find_in_batches_should_return_a_sized_enumerator
   test ".find_each respects table alias" do
     assert_queries_count(1) do
       table_alias = Post.arel_table.alias("omg_posts")
-      table_metadata = ActiveRecord::TableMetadata.new(Post, table_alias)
-      predicate_builder = ActiveRecord::PredicateBuilder.new(table_metadata)
-
-      posts = ActiveRecord::Relation.create(
-        Post,
-        table: table_alias,
-        predicate_builder: predicate_builder
-      )
+
+      posts = ActiveRecord::Relation.create(Post, table: table_alias)
       posts.find_each { }
     end
   end

activerecord/test/cases/collection_cache_key_test.rb

@@ -72,14 +72,8 @@ class CollectionCacheKeyTest < ActiveRecord::TestCase
 
     test "cache_key for relation with table alias" do
       table_alias = Developer.arel_table.alias("omg_developers")
-      table_metadata = ActiveRecord::TableMetadata.new(Developer, table_alias)
-      predicate_builder = ActiveRecord::PredicateBuilder.new(table_metadata)
-
-      developers = ActiveRecord::Relation.create(
-        Developer,
-        table: table_alias,
-        predicate_builder: predicate_builder
-      )
+
+      developers = ActiveRecord::Relation.create(Developer, table: table_alias)
       developers = developers.where(salary: 100000).order(updated_at: :desc)
       last_developer_timestamp = developers.first.updated_at
 

activerecord/test/cases/relations_test.rb

@@ -2458,14 +2458,8 @@ def test_find_by_with_take_memoization
   private
     def custom_post_relation(alias_name = "omg_posts")
       table_alias = Post.arel_table.alias(alias_name)
-      table_metadata = ActiveRecord::TableMetadata.new(Post, table_alias)
-      predicate_builder = ActiveRecord::PredicateBuilder.new(table_metadata)
 
-      ActiveRecord::Relation.create(
-        Post,
-        table: table_alias,
-        predicate_builder: predicate_builder
-      )
+      ActiveRecord::Relation.create(Post, table: table_alias)
     end
 end