Add support for JSON time_precision to Time and DateTime

Author: pixeltrix

activesupport/lib/active_support/core_ext/object/json.rb

@@ -16,12 +16,12 @@
 # otherwise they will always use to_json gem implementation, which is backwards incompatible in
 # several cases (for instance, the JSON implementation for Hash does not work) with inheritance
 # and consequently classes as ActiveSupport::OrderedHash cannot be serialized to json.
-# 
+#
 # On the other hand, we should avoid conflict with ::JSON.{generate,dump}(obj). Unfortunately, the
 # JSON gem's encoder relies on its own to_json implementation to encode objects. Since it always
 # passes a ::JSON::State object as the only argument to to_json, we can detect that and forward the
 # calls to the original to_json method.
-# 
+#
 # It should be noted that when using ::JSON.{generate,dump} directly, ActiveSupport's encoder is
 # bypassed completely. This means that as_json won't be invoked and the JSON gem will simply
 # ignore any options it does not natively understand. This also means that ::JSON.{generate,dump}
@@ -163,7 +163,7 @@ def as_json(options = nil) #:nodoc:
 class Time
   def as_json(options = nil) #:nodoc:
     if ActiveSupport.use_standard_json_time_format
-      xmlschema(3)
+      xmlschema(ActiveSupport::JSON::Encoding.time_precision)
     else
       %(#{strftime("%Y/%m/%d %H:%M:%S")} #{formatted_offset(false)})
     end
@@ -183,7 +183,7 @@ def as_json(options = nil) #:nodoc:
 class DateTime
   def as_json(options = nil) #:nodoc:
     if ActiveSupport.use_standard_json_time_format
-      xmlschema(3)
+      xmlschema(ActiveSupport::JSON::Encoding.time_precision)
     else
       strftime('%Y/%m/%d %H:%M:%S %z')
     end

activesupport/lib/active_support/json/encoding.rb

@@ -166,6 +166,7 @@ def const_missing(name)
       self.use_standard_json_time_format = true
       self.escape_html_entities_in_json  = true
       self.json_encoder = JSONGemEncoder
+      self.time_precision = 3
     end
   end
 end

activesupport/lib/active_support/time_with_zone.rb

@@ -154,8 +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.time_precision || 3
-        xmlschema(digits)
+        xmlschema(ActiveSupport::JSON::Encoding.time_precision)
       else
         %(#{time.strftime("%Y/%m/%d %H:%M:%S")} #{formatted_offset(false)})
       end

activesupport/test/json/encoding_test.rb

@@ -474,7 +474,25 @@ def test_twz_to_json_with_custom_time_precision
       assert_equal "\"1999-12-31T19:00:00-05:00\"", ActiveSupport::JSON.encode(time)
     end
   ensure
-    ActiveSupport::JSON::Encoding.time_precision = nil
+    ActiveSupport::JSON::Encoding.time_precision = 3
+  end
+
+  def test_time_to_json_with_custom_time_precision
+    with_standard_json_time_format(true) do
+      ActiveSupport::JSON::Encoding.time_precision = 0
+      assert_equal "\"2000-01-01T00:00:00Z\"", ActiveSupport::JSON.encode(Time.utc(2000))
+    end
+  ensure
+    ActiveSupport::JSON::Encoding.time_precision = 3
+  end
+
+  def test_datetime_to_json_with_custom_time_precision
+    with_standard_json_time_format(true) do
+      ActiveSupport::JSON::Encoding.time_precision = 0
+      assert_equal "\"2000-01-01T00:00:00+00:00\"", ActiveSupport::JSON.encode(DateTime.new(2000))
+    end
+  ensure
+    ActiveSupport::JSON::Encoding.time_precision = 3
   end
 
   def test_twz_to_json_when_wrapping_a_date_time