Do not raise errors on 422 responses

JSON APIs often return validation errors with 422 so the client would be
notified that the response was not successful by the existence of the
resource errors.

Author: jamesstonehill

lib/json_api_client/middleware/status.rb

@@ -28,6 +28,8 @@ def handle_status(code, env)
           raise Errors::NotFound, env[:url]
         when 409
           raise Errors::Conflict, env
+        when 422
+          # Allow to proceed as resource errors will be populated
         when 400..499
           raise Errors::ClientError, env
         when 500..599

test/unit/status_test.rb

@@ -69,4 +69,16 @@ def test_server_responding_with_408_status
       User.find(1)
     end
   end
+
+  def test_server_responding_with_422_status
+    stub_request(:get, "http://example.com/users/1")
+      .to_return(headers: {content_type: "application/vnd.api+json"}, body: {
+        meta: {
+          status: 422
+        }
+      }.to_json)
+
+    # We want to test that this response does not raise an error
+    User.find(1)
+  end
 end