Refactor tz aware types, add support for PG ranges

This is an alternate implementation to #22875, that generalizes a lot of
the logic that type decorators are going to need, in order to have them
work with arrays, ranges, etc. The types have the ability to map over a
value, with the default implementation being to just yield that given
value. Array and Range give more appropriate definitions.

This does not automatically make ranges time zone aware, as they need to
be added to the `time_zone_aware` types config, but we could certainly
make that change if we feel it is appropriate. I do think this would be
a breaking change however, and should at least have a deprecation cycle.

Closes #22875.

/cc @matthewd

activemodel/lib/active_model/type/value.rb

@@ -84,6 +84,10 @@ def changed_in_place?(raw_old_value, new_value)
         false
       end
 
+      def map(value) # :nodoc:
+        yield value
+      end
+
       def ==(other)
         self.class == other.class &&
           precision == other.precision &&

activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb

@@ -9,9 +9,9 @@ def deserialize(value)
         end
 
         def cast(value)
-          if value.is_a?(Array)
-            value.map { |v| cast(v) }
-          elsif value.is_a?(Hash)
+          return if value.nil?
+
+          if value.is_a?(Hash)
             set_time_zone_without_conversion(super)
           elsif value.respond_to?(:in_time_zone)
             begin
@@ -19,18 +19,20 @@ def cast(value)
             rescue ArgumentError
               nil
             end
+          else
+            map(super) { |t| cast(t) }
           end
         end
 
         private
 
         def convert_time_to_time_zone(value)
-          if value.is_a?(Array)
-            value.map { |v| convert_time_to_time_zone(v) }
-          elsif value.acts_like?(:time)
+          return if value.nil?
+
+          if value.acts_like?(:time)
             value.in_time_zone
           else
-            value
+            map(value) { |v| convert_time_to_time_zone(v) }
           end
         end
 

activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb

@@ -50,6 +50,10 @@ def type_cast_for_schema(value)
             "[" + value.map { |v| subtype.type_cast_for_schema(v) }.join(", ") + "]"
           end
 
+          def map(value, &block)
+            value.map(&block)
+          end
+
           private
 
           def type_cast_array(value, method)

activerecord/lib/active_record/connection_adapters/postgresql/oid/range.rb

@@ -6,6 +6,7 @@ module PostgreSQL
       module OID # :nodoc:
         class Range < Type::Value # :nodoc:
           attr_reader :subtype, :type
+          delegate :user_input_in_time_zone, to: :subtype
 
           def initialize(subtype, type = :range)
             @subtype = subtype
@@ -18,7 +19,7 @@ def type_cast_for_schema(value)
 
           def cast_value(value)
             return if value == 'empty'
-            return value if value.is_a?(::Range)
+            return value unless value.is_a?(::String)
 
             extracted = extract_bounds(value)
             from = type_cast_single extracted[:from]
@@ -46,6 +47,12 @@ def ==(other)
               other.type == type
           end
 
+          def map(value) # :nodoc:
+            new_begin = yield(value.begin)
+            new_end = yield(value.end)
+            ::Range.new(new_begin, new_end, value.exclude_end?)
+          end
+
           private
 
           def type_cast_single(value)

activerecord/test/cases/adapters/postgresql/range_test.rb

@@ -4,11 +4,13 @@
 if ActiveRecord::Base.connection.respond_to?(:supports_ranges?) && ActiveRecord::Base.connection.supports_ranges?
   class PostgresqlRange < ActiveRecord::Base
     self.table_name = "postgresql_ranges"
+    self.time_zone_aware_types += [:tsrange, :tstzrange]
   end
 
   class PostgresqlRangeTest < ActiveRecord::PostgreSQLTestCase
     self.use_transactional_tests = false
     include ConnectionHelper
+    include InTimeZone
 
     def setup
       @connection = PostgresqlRange.connection
@@ -160,6 +162,26 @@ def test_custom_range_values
       assert_nil @empty_range.float_range
     end
 
+    def test_timezone_awareness_tzrange
+      tz = "Pacific Time (US & Canada)"
+
+      in_time_zone tz do
+        PostgresqlRange.reset_column_information
+        time_string = Time.current.to_s
+        time = Time.zone.parse(time_string)
+
+        record = PostgresqlRange.new(tstz_range: time_string..time_string)
+        assert_equal time..time, record.tstz_range
+        assert_equal ActiveSupport::TimeZone[tz], record.tstz_range.begin.time_zone
+
+        record.save!
+        record.reload
+
+        assert_equal time..time, record.tstz_range
+        assert_equal ActiveSupport::TimeZone[tz], record.tstz_range.begin.time_zone
+      end
+    end
+
     def test_create_tstzrange
       tstzrange = Time.parse('2010-01-01 14:30:00 +0100')...Time.parse('2011-02-02 14:30:00 CDT')
       round_trip(@new_range, :tstz_range, tstzrange)
@@ -188,6 +210,26 @@ def test_update_tsrange
                             Time.send(tz, 2010, 1, 1, 14, 30, 0)...Time.send(tz, 2010, 1, 1, 14, 30, 0))
     end
 
+    def test_timezone_awareness_tsrange
+      tz = "Pacific Time (US & Canada)"
+
+      in_time_zone tz do
+        PostgresqlRange.reset_column_information
+        time_string = Time.current.to_s
+        time = Time.zone.parse(time_string)
+
+        record = PostgresqlRange.new(ts_range: time_string..time_string)
+        assert_equal time..time, record.ts_range
+        assert_equal ActiveSupport::TimeZone[tz], record.ts_range.begin.time_zone
+
+        record.save!
+        record.reload
+
+        assert_equal time..time, record.ts_range
+        assert_equal ActiveSupport::TimeZone[tz], record.ts_range.begin.time_zone
+      end
+    end
+
     def test_create_numrange
       assert_equal_round_trip(@new_range, :num_range,
                               BigDecimal.new('0.5')...BigDecimal.new('1'))