opt out of truncating times (#72)

lib/subroutine.rb

@@ -33,4 +33,12 @@ def self.inheritable_field_options
     @inheritable_field_options ||= %i[mass_assignable field_reader field_writer groups aka]
   end
 
+  def self.preserve_time_precision=(bool)
+    @preserve_time_precision = !!bool
+  end
+
+  def self.preserve_time_precision?
+    !!@preserve_time_precision
+  end
+
 end

lib/subroutine/type_caster.rb

@@ -4,6 +4,7 @@
 require 'time'
 require 'bigdecimal'
 require 'securerandom'
+require 'active_support/json'
 require 'active_support/core_ext/date_time/acts_like'
 require 'active_support/core_ext/date_time/calculations'
 require 'active_support/core_ext/object/acts_like'
@@ -111,7 +112,7 @@ def self.cast(value, options = {})
   t ||= value if value.is_a?(::Time)
   t ||= value if value.try(:acts_like?, :time)
   t ||= ::Time.parse(String(value))
-  t.utc.iso8601
+  t.utc.iso8601(::ActiveSupport::JSON::Encoding.time_precision)
 end
 
 ::Subroutine::TypeCaster.register :date do |value, _options = {}|
@@ -123,21 +124,16 @@ def self.cast(value, options = {})
 ::Subroutine::TypeCaster.register :time, :timestamp, :datetime do |value, options = {}|
   next nil unless value.present?
 
-  if options[:precision] == :high
-    if value.try(:acts_like?, :time)
-      value.to_time
-    else
-      ::Time.parse(String(value))
-    end
-  else # precision == :seconds
-    time = if value.try(:acts_like?, :time)
-      value.to_time
-    else
-      ::Time.parse(String(value))
-    end
-
-    time.change(usec: 0)
+  value = if value.try(:acts_like?, :time)
+    value.to_time
+  else
+    ::Time.parse(String(value))
   end
+
+  # High precision must be opted into. The original implementation is to set usec:0
+  next value if options[:precision] == :high || ::Subroutine.preserve_time_precision?
+
+  value.change(usec: 0)
 end
 
 ::Subroutine::TypeCaster.register :hash, :object, :hashmap, :dict do |value, _options = {}|

test/subroutine/type_caster_test.rb

@@ -438,11 +438,11 @@ def test_iso_time_inputs
 
       op.iso_time_input = '2022-12-22T10:30:24Z'
       assert_equal ::String, op.iso_time_input.class
-      assert_equal '2022-12-22T10:30:24Z', op.iso_time_input
+      assert_equal '2022-12-22T10:30:24.000Z', op.iso_time_input
 
-      op.iso_time_input = Time.parse('2022-12-22T10:30:24Z')
+      op.iso_time_input = Time.parse('2022-12-22T10:30:24.123456Z')
       assert_equal ::String, op.iso_time_input.class
-      assert_equal '2022-12-22T10:30:24Z', op.iso_time_input
+      assert_equal '2022-12-22T10:30:24.123Z', op.iso_time_input
     end
 
     def test_file_inputs