Rename subsecond_fraction_digits option to time_precision

activesupport/lib/active_support/json/encoding.rb

@@ -4,7 +4,7 @@
 module ActiveSupport
   class << self
     delegate :use_standard_json_time_format, :use_standard_json_time_format=,
-      :subsecond_fraction_digits, :subsecond_fraction_digits=,
+      :time_precision, :time_precision=,
       :escape_html_entities_in_json, :escape_html_entities_in_json=,
       :encode_big_decimal_as_string, :encode_big_decimal_as_string=,
       :json_encoder, :json_encoder=,
@@ -106,9 +106,9 @@ class << self
         # as a safety measure.
         attr_accessor :escape_html_entities_in_json
 
-        # Configures the inclusion of subsecond resolution when serializing instances
-        # of ActiveSupport::TimeWithZone.
-        attr_accessor :subsecond_fraction_digits
+        # Sets the precision of encoded time values.
+        # Defaults to 3 (equivalent to millisecond precision)
+        attr_accessor :time_precision
 
         # Sets the encoder used by Rails to encode Ruby objects into JSON strings
         # in +Object#to_json+ and +ActiveSupport::JSON.encode+.

activesupport/lib/active_support/time_with_zone.rb

@@ -154,7 +154,7 @@ def xmlschema(fraction_digits = 0)
     #   # => "2005/02/01 05:15:10 -1000"
     def as_json(options = nil)
       if ActiveSupport::JSON::Encoding.use_standard_json_time_format
-        digits = ActiveSupport::JSON::Encoding.subsecond_fraction_digits || 3
+        digits = ActiveSupport::JSON::Encoding.time_precision || 3
         xmlschema(digits)
       else
         %(#{time.strftime("%Y/%m/%d %H:%M:%S")} #{formatted_offset(false)})

activesupport/test/json/encoding_test.rb

@@ -466,15 +466,15 @@ def test_twz_to_json_with_use_standard_json_time_format_config_set_to_true
     end
   end
 
-  def test_twz_to_json_with_custom_subsecond_resolution
+  def test_twz_to_json_with_custom_time_precision
     with_standard_json_time_format(true) do
-      ActiveSupport::JSON::Encoding.subsecond_fraction_digits = 0
+      ActiveSupport::JSON::Encoding.time_precision = 0
       zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
       time = ActiveSupport::TimeWithZone.new(Time.utc(2000), zone)
       assert_equal "\"1999-12-31T19:00:00-05:00\"", ActiveSupport::JSON.encode(time)
     end
   ensure
-    ActiveSupport::JSON::Encoding.subsecond_fraction_digits = nil
+    ActiveSupport::JSON::Encoding.time_precision = nil
   end
 
   def test_twz_to_json_when_wrapping_a_date_time

guides/source/configuring.md

@@ -441,6 +441,8 @@ There are a few configuration options available in Active Support:
 
 * `config.active_support.use_standard_json_time_format` enables or disables serializing dates to ISO 8601 format. Defaults to `true`.
 
+* `config.active_support.time_precision` sets the precision of JSON encoded time values. Defaults to `3`.
+
 * `ActiveSupport::Logger.silencer` is set to `false` to disable the ability to silence logging in a block. The default is `true`.
 
 * `ActiveSupport::Cache::Store.logger` specifies the logger to use within cache store operations.