Use an `Attribute` object to represent a bind value

The column is primarily used for type casting, which we're trying to
separate from the idea of a column. Since what we really need is the
combination of a name, type, and value, let's use the object that we
already have to represent that concept, rather than this tuple. No
consumers of the bind values have been changed, only the producers
(outside of tests which care too much about internals). This is
*finally* possible since the bind values are now produced from a
reasonable number of lcoations.

6 files changed, 25 insertions, 16 deletions

diff --git a/activerecord/lib/active_record/associations/join_dependency/join_association.rb b/activerecord/lib/active_record/associations/join_dependency/join_association.rb
index c1ef86a95b..3a184cee37 100644
--- a/activerecord/lib/active_record/associations/join_dependency/join_association.rb
+++ b/activerecord/lib/active_record/associations/join_dependency/join_association.rb
@@ -25,7 +25,7 @@ module ActiveRecord
 
         def join_constraints(foreign_table, foreign_klass, node, join_type, tables, scope_chain, chain)
           joins         = []
-          bind_values   = []
+          binds         = []
           tables        = tables.reverse
 
           scope_chain_index = 0
@@ -66,7 +66,7 @@ module ActiveRecord
             end
 
             if rel && !rel.arel.constraints.empty?
-              bind_values.concat rel.bind_values
+              binds += rel.bound_attributes
               constraint = constraint.and rel.arel.constraints
             end
 
@@ -75,7 +75,7 @@ module ActiveRecord
               column = klass.columns_hash[reflection.type.to_s]
 
               substitute = klass.connection.substitute_at(column)
-              bind_values.push [column, value]
+              binds << Attribute.with_cast_value(column.name, value, klass.type_for_attribute(column.name))
               constraint = constraint.and table[reflection.type].eq substitute
             end
 
@@ -85,7 +85,7 @@ module ActiveRecord
             foreign_table, foreign_klass = table, klass
           end
 
-          JoinInformation.new joins, bind_values
+          JoinInformation.new joins, binds
         end
 
         #  Builds equality condition.
diff --git a/activerecord/lib/active_record/relation/from_clause.rb b/activerecord/lib/active_record/relation/from_clause.rb
index 8022901524..a93952fa30 100644
--- a/activerecord/lib/active_record/relation/from_clause.rb
+++ b/activerecord/lib/active_record/relation/from_clause.rb
@@ -10,7 +10,7 @@ module ActiveRecord
 
       def binds
         if value.is_a?(Relation)
-          value.bind_values
+          value.bound_attributes
         else
           []
         end
diff --git a/activerecord/lib/active_record/relation/predicate_builder.rb b/activerecord/lib/active_record/relation/predicate_builder.rb
index 90790322b4..7b605db88c 100644
--- a/activerecord/lib/active_record/relation/predicate_builder.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder.rb
@@ -104,11 +104,11 @@ module ActiveRecord
           result[column_name] = attrs
           binds += bvs
         when Relation
-          binds += value.bind_values
+          binds += value.bound_attributes
         else
           if can_be_bound?(column_name, value)
             result[column_name] = Arel::Nodes::BindParam.new
-            binds.push([table.column(column_name), value])
+            binds << Attribute.with_cast_value(column_name.to_s, value, table.type(column_name))
           end
         end
       end
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index a270f23d7d..bc5f126a23 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -92,10 +92,20 @@ module ActiveRecord
       CODE
     end
 
-    def bind_values
+    def bound_attributes
       from_clause.binds + arel.bind_values + where_clause.binds + having_clause.binds
     end
 
+    def bind_values
+      # convert to old style
+      bound_attributes.map do |attribute|
+        if attribute.name
+          column = ConnectionAdapters::Column.new(attribute.name, nil, attribute.type)
+        end
+        [column, attribute.value_before_type_cast]
+      end
+    end
+
     def create_with_value # :nodoc:
       @values[:create_with] || {}
     end
diff --git a/activerecord/lib/active_record/relation/where_clause.rb b/activerecord/lib/active_record/relation/where_clause.rb
index 1a70dc447e..ae5667dfd6 100644
--- a/activerecord/lib/active_record/relation/where_clause.rb
+++ b/activerecord/lib/active_record/relation/where_clause.rb
@@ -39,7 +39,7 @@ module ActiveRecord
           end
         end
 
-        binds = self.binds.select(&:first).to_h.transform_keys(&:name)
+        binds = self.binds.map { |attr| [attr.name, attr.value] }.to_h
 
         equalities.map { |node|
           name = node.left.name
@@ -97,7 +97,7 @@ module ActiveRecord
       def non_conflicting_binds(other)
         conflicts = referenced_columns & other.referenced_columns
         conflicts.map! { |node| node.name.to_s }
-        binds.reject { |col, _| conflicts.include?(col.name) }
+        binds.reject { |attr| conflicts.include?(attr.name) }
       end
 
       def inverted_predicates
@@ -130,8 +130,8 @@ module ActiveRecord
       end
 
       def binds_except(columns)
-        binds.reject do |column, _|
-          columns.include?(column.name)
+        binds.reject do |attr|
+          columns.include?(attr.name)
         end
       end
 
diff --git a/activerecord/lib/active_record/table_metadata.rb b/activerecord/lib/active_record/table_metadata.rb
index 3707fd3f04..6c8792ee80 100644
--- a/activerecord/lib/active_record/table_metadata.rb
+++ b/activerecord/lib/active_record/table_metadata.rb
@@ -22,12 +22,11 @@ module ActiveRecord
       arel_table[column_name]
     end
 
-    def column(column_name)
+    def type(column_name)
       if klass
-        klass.columns_hash[column_name.to_s]
+        klass.type_for_attribute(column_name.to_s)
       else
-        # FIXME: We really shouldn't need to do this.
-        ConnectionAdapters::Column.new(column_name.to_s, nil, Type::Value.new)
+        Type::Value.new
       end
     end