Remove most type related predicates from `Column`

Remaining are `limit`, `precision`, `scale`, and `type` (the symbol
version). These will remain on the column, since they mirror the options
to the `column` method in the schema definition DSL

8 files changed, 17 insertions, 18 deletions

diff --git a/activerecord/lib/active_record/associations/preloader/association.rb b/activerecord/lib/active_record/associations/preloader/association.rb
index 9e4a2b925c..1dc8bff193 100644
--- a/activerecord/lib/active_record/associations/preloader/association.rb
+++ b/activerecord/lib/active_record/associations/preloader/association.rb
@@ -104,11 +104,11 @@ module ActiveRecord
         end
 
         def association_key_type
-          @klass.column_for_attribute(association_key_name).type
+          @klass.type_for_attribute(association_key_name.to_s).type
         end
 
         def owner_key_type
-          @model.column_for_attribute(owner_key_name).type
+          @model.type_for_attribute(owner_key_name.to_s).type
         end
 
         def load_slices(slices)
diff --git a/activerecord/lib/active_record/attribute_methods/query.rb b/activerecord/lib/active_record/attribute_methods/query.rb
index dc689f399a..83b858aae7 100644
--- a/activerecord/lib/active_record/attribute_methods/query.rb
+++ b/activerecord/lib/active_record/attribute_methods/query.rb
@@ -15,6 +15,7 @@ module ActiveRecord
         when false, nil  then false
         else
           column = self.class.columns_hash[attr_name]
+          type = self.class.type_for_attribute(attr_name)
           if column.nil?
             if Numeric === value || value !~ /[^0-9]/
               !value.to_i.zero?
@@ -22,7 +23,7 @@ module ActiveRecord
               return false if ActiveRecord::ConnectionAdapters::Column::FALSE_VALUES.include?(value)
               !value.blank?
             end
-          elsif column.number?
+          elsif type.number?
             !value.zero?
           else
             !value.blank?
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
index 42ea599a74..932aaf7aa7 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
@@ -46,9 +46,10 @@ module ActiveRecord
       private
 
       def schema_default(column)
-        default = column.type_cast_from_database(column.default)
+        type = lookup_cast_type_from_column(column)
+        default = type.type_cast_from_database(column.default)
         unless default.nil?
-          column.type_cast_for_schema(default)
+          type.type_cast_for_schema(default)
         end
       end
     end
diff --git a/activerecord/lib/active_record/connection_adapters/column.rb b/activerecord/lib/active_record/connection_adapters/column.rb
index e74de60a83..a489141d1a 100644
--- a/activerecord/lib/active_record/connection_adapters/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/column.rb
@@ -14,11 +14,7 @@ module ActiveRecord
 
       attr_reader :name, :cast_type, :null, :sql_type, :default, :default_function
 
-      delegate :type, :precision, :scale, :limit, :klass, :accessor,
-        :text?, :number?, :binary?, :changed?,
-        :type_cast_from_user, :type_cast_from_database, :type_cast_for_database,
-        :type_cast_for_schema,
-        to: :cast_type
+      delegate :precision, :scale, :limit, :type, to: :cast_type
 
       # Instantiates a new column in the table.
       #
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index 4705f129f2..e68b2c399c 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -210,7 +210,7 @@ module ActiveRecord
         elsif !connected?
           "#{super} (call '#{super}.connection' to establish a connection)"
         elsif table_exists?
-          attr_list = columns.map { |c| "#{c.name}: #{c.type}" } * ', '
+          attr_list = column_types.map { |name, type| "#{name}: #{type.type}" } * ', '
           "#{super}(#{attr_list})"
         else
           "#{super}(Table doesn't exist)"
diff --git a/activerecord/lib/active_record/fixtures.rb b/activerecord/lib/active_record/fixtures.rb
index 10e9be20b5..5b1b7fe73d 100644
--- a/activerecord/lib/active_record/fixtures.rb
+++ b/activerecord/lib/active_record/fixtures.rb
@@ -661,7 +661,7 @@ module ActiveRecord
                   row[association.foreign_type] = $1
                 end
 
-                fk_type = association.active_record.columns_hash[fk_name].type
+                fk_type = association.active_record.type_for_attribute(fk_name).type
                 row[fk_name] = ActiveRecord::FixtureSet.identify(value, fk_type)
               end
             when :has_many
@@ -691,7 +691,7 @@ module ActiveRecord
       end
 
       def primary_key_type
-        @association.klass.column_types[@association.klass.primary_key].type
+        @association.klass.type_for_attribute(@association.klass.primary_key).type
       end
     end
 
@@ -711,7 +711,7 @@ module ActiveRecord
       end
 
       def primary_key_type
-        @primary_key_type ||= model_class && model_class.column_types[model_class.primary_key].type
+        @primary_key_type ||= model_class && model_class.type_for_attribute(model_class.primary_key).type
       end
 
       def add_join_records(rows, row, association)
diff --git a/activerecord/lib/active_record/serializers/xml_serializer.rb b/activerecord/lib/active_record/serializers/xml_serializer.rb
index c2484d02ed..89b7e0be82 100644
--- a/activerecord/lib/active_record/serializers/xml_serializer.rb
+++ b/activerecord/lib/active_record/serializers/xml_serializer.rb
@@ -180,9 +180,9 @@ module ActiveRecord #:nodoc:
     class Attribute < ActiveModel::Serializers::Xml::Serializer::Attribute #:nodoc:
       def compute_type
         klass = @serializable.class
-        column = klass.columns_hash[name] || Type::Value.new
+        cast_type = klass.type_for_attribute(name)
 
-        type = ActiveSupport::XmlMini::TYPE_NAMES[value.class.name] || column.type
+        type = ActiveSupport::XmlMini::TYPE_NAMES[value.class.name] || cast_type.type
 
         { :text => :string,
           :time => :datetime }[type] || type
diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb
index f52f91e89c..8f7a46f2c7 100644
--- a/activerecord/lib/active_record/validations/uniqueness.rb
+++ b/activerecord/lib/active_record/validations/uniqueness.rb
@@ -59,7 +59,8 @@ module ActiveRecord
         end
 
         column = klass.columns_hash[attribute_name]
-        value = klass.type_for_attribute(attribute_name).type_cast_for_database(value)
+        cast_type = klass.type_for_attribute(attribute_name)
+        value = cast_type.type_cast_for_database(value)
         value = klass.connection.type_cast(value)
         if value.is_a?(String) && column.limit
           value = value.to_s[0, column.limit]
@@ -67,7 +68,7 @@ module ActiveRecord
 
         value = Arel::Nodes::Quoted.new(value)
 
-        comparison = if !options[:case_sensitive] && value && column.text?
+        comparison = if !options[:case_sensitive] && value && cast_type.text?
           # will use SQL LOWER function before comparison, unless it detects a case insensitive collation
           klass.connection.case_insensitive_comparison(table, attribute, column, value)
         else