Validate email domains

The gem checks the DNS system for a valid domain entry.

app/models/spree/user.rb

@@ -48,7 +48,7 @@ module Spree
 
     after_create :associate_customers, :associate_orders
 
-    validates :email, 'valid_email_2/email': true, if: :email_changed?
+    validates :email, 'valid_email_2/email': { mx: true }, if: :email_changed?
     validate :limit_owned_enterprises
     validates :uid, uniqueness: true, if: lambda { uid.present? }
     validates_email :uid, if: lambda { uid.present? }

spec/base_spec_helper.rb

@@ -127,6 +127,15 @@ RSpec.configure do |config|
     end
   end
 
+  # Don't validate our invalid test data with expensive network requests.
+  config.before(:each) do
+    allow_any_instance_of(ValidEmail2::Address).to receive_messages(
+      valid_mx?: true,
+      valid_strict_mx?: true,
+      mx_server_is_in?: false
+    )
+  end
+
   # Webmock raises errors that inherit directly from Exception (not StandardError).
   # The messages contain useful information for debugging stubbed requests to external
   # services (in tests), but they normally don't appear in the test output.

spec/models/spree/user_spec.rb

@@ -102,7 +102,10 @@ describe Spree::User do
       expect(user).to be_valid
     end
 
-    pending "detects typos in the domain" do
+    it "detects typos in the domain" do
+      # We mock this validation in all other tests because our test data is not
+      # valid, the network requests slow down tests and could make them flaky.
+      expect_any_instance_of(ValidEmail2::Address).to receive(:valid_mx?).and_call_original
       user.email = "example@ho020tmail.com"
       expect(user).to_not be_valid
     end