Make sure ActiveResource::Errors#from_json doesn't pass nil to #from_…

…array [#3650 state:commited]

Signed-off-by: José Valim <jose.valim@gmail.com>

activeresource/lib/active_resource/validations.rb

@@ -27,7 +27,7 @@ def from_array(messages, save_cache = false)
 
     # Grabs errors from a json response.
     def from_json(json, save_cache = false)
-      array = ActiveSupport::JSON.decode(json)['errors'] rescue []
+      array = Array.wrap(ActiveSupport::JSON.decode(json)['errors']) rescue []
       from_array array, save_cache
     end
 

activeresource/test/cases/base_errors_test.rb

@@ -17,7 +17,7 @@ def test_should_mark_as_invalid
     end
   end
 
-  def test_should_parse_xml_errors
+  def test_should_parse_json_and_xml_errors
     [ :json, :xml ].each do |format|
       invalid_user_using_format(format) do
         assert_kind_of ActiveResource::Errors, @person.errors
@@ -26,6 +26,17 @@ def test_should_parse_xml_errors
     end
   end
 
+  def test_should_parse_json_errors_when_no_errors_key
+    ActiveResource::HttpMock.respond_to do |mock|
+      mock.post "/people.json", {}, '{}', 422, {'Content-Type' => 'application/json; charset=utf-8'}
+    end
+
+    invalid_user_using_format(:json) do
+      assert_kind_of ActiveResource::Errors, @person.errors
+      assert_equal 0, @person.errors.size
+    end
+  end
+
   def test_should_parse_errors_to_individual_attributes
     [ :json, :xml ].each do |format|
       invalid_user_using_format(format) do