Use correct timezone when parsing date in json

Fixes https://github.com/rails/rails/issues/22171

Time specified in ISO 8601 format without `Z` should be considered as local
time, yet until now it was treated as UTC.

This commit fixes problem by parsing time using timezone specified in
application config.

The downside of this solution is performance hit (`Time.zone.parse` is ~ 1.6x
slower than `Time.parse`), so maybe there's a better solution.

1 files changed, 11 insertions, 5 deletions

diff --git a/activesupport/test/json/decoding_test.rb b/activesupport/test/json/decoding_test.rb
index f2fc456f4b..887ef1681d 100644
--- a/activesupport/test/json/decoding_test.rb
+++ b/activesupport/test/json/decoding_test.rb
@@ -1,8 +1,11 @@
 require 'abstract_unit'
 require 'active_support/json'
 require 'active_support/time'
+require 'time_zone_test_helpers'
 
 class TestJSONDecoding < ActiveSupport::TestCase
+  include TimeZoneTestHelpers
+
   class Foo
     def self.json_create(object)
       "Foo"
@@ -24,10 +27,11 @@ class TestJSONDecoding < ActiveSupport::TestCase
     %(["2007-01-01 01:12:34 Z"])                 => [Time.utc(2007, 1, 1, 1, 12, 34)],
     %(["2007-01-01 01:12:34 Z", "2007-01-01 01:12:35 Z"]) => [Time.utc(2007, 1, 1, 1, 12, 34), Time.utc(2007, 1, 1, 1, 12, 35)],
     # no time zone
-    %({"a": "2007-01-01 01:12:34"})              => {'a' => "2007-01-01 01:12:34"},
+    %({"a": "2007-01-01 01:12:34"})              => {'a' => Time.new(2007, 1, 1, 1, 12, 34, "-05:00")},
     # invalid date
     %({"a": "1089-10-40"})                       => {'a' => "1089-10-40"},
     # xmlschema date notation
+    %({"a": "2009-08-10T19:01:02"})              => {'a' => Time.new(2009, 8, 10, 19, 1, 2, "-04:00")},
     %({"a": "2009-08-10T19:01:02Z"})             => {'a' => Time.utc(2009, 8, 10, 19, 1, 2)},
     %({"a": "2009-08-10T19:01:02+02:00"})        => {'a' => Time.utc(2009, 8, 10, 17, 1, 2)},
     %({"a": "2009-08-10T19:01:02-05:00"})        => {'a' => Time.utc(2009, 8, 11, 00, 1, 2)},
@@ -72,10 +76,12 @@ class TestJSONDecoding < ActiveSupport::TestCase
 
   TESTS.each_with_index do |(json, expected), index|
     test "json decodes #{index}" do
-      with_parse_json_times(true) do
-        silence_warnings do
-          assert_equal expected, ActiveSupport::JSON.decode(json), "JSON decoding \
-          failed for #{json}"
+      with_tz_default 'Eastern Time (US & Canada)' do
+        with_parse_json_times(true) do
+          silence_warnings do
+            assert_equal expected, ActiveSupport::JSON.decode(json), "JSON decoding \
+            failed for #{json}"
+          end
         end
       end
     end