Merge pull request #173 from lostapathy/strict_mx

Add strict_mx validation

README.md

@@ -43,10 +43,14 @@ class User < ActiveRecord::Base
 end
 ```
 
-To validate that the domain has a MX record:
+To validate that the domain has an MX record or A record:
 ```ruby
 validates :email, 'valid_email_2/email': { mx: true }
 ```
+To validate strictly that the domain has an MX record:
+```ruby
+validates :email, 'valid_email_2/email': { strict_mx: true }
+```
 
 To validate that the domain is not a disposable email (checks domain and MX server):
 ```ruby
@@ -109,6 +113,7 @@ address = ValidEmail2::Address.new("lisinge@gmail.com")
 address.valid? => true
 address.disposable? => false
 address.valid_mx? => true
+address.valid_strict_mx? => true
 address.subaddressed? => false
 ```
 
@@ -120,6 +125,7 @@ Do so by adding this in your `spec_helper`:
 ```ruby
 config.before(:each) do
   allow_any_instance_of(ValidEmail2::Address).to receive(:valid_mx?).and_return(true)
+  allow_any_instance_of(ValidEmail2::Address).to receive(:valid_strict_mx?).and_return(true)
 end
 ```
 

lib/valid_email2/address.rb

@@ -85,6 +85,12 @@ def blacklisted?
     def valid_mx?
       return false unless valid?
 
+      mx_or_a_servers.any?
+    end
+
+    def valid_strict_mx?
+      return false unless valid?
+
       mx_servers.any?
     end
 
@@ -119,7 +125,12 @@ def address_contain_emoticons?(email)
 
     def mx_servers
       @mx_servers ||= Resolv::DNS.open do |dns|
-        mx_servers = dns.getresources(address.domain, Resolv::DNS::Resource::IN::MX)
+        dns.getresources(address.domain, Resolv::DNS::Resource::IN::MX)
+      end
+    end
+
+    def mx_or_a_servers
+      @mx_or_a_servers ||= Resolv::DNS.open do |dns|
         (mx_servers.any? && mx_servers) ||
           dns.getresources(address.domain, Resolv::DNS::Resource::IN::A)
       end

lib/valid_email2/email_validator.rb

@@ -5,7 +5,7 @@
 module ValidEmail2
   class EmailValidator < ActiveModel::EachValidator
     def default_options
-      { regex: true, disposable: false, mx: false, disallow_subaddressing: false, multiple: false }
+      { regex: true, disposable: false, mx: false, strict_mx: false, disallow_subaddressing: false, multiple: false }
     end
 
     def validate_each(record, attribute, value)
@@ -48,6 +48,10 @@ def validate_each(record, attribute, value)
       if options[:mx]
         error(record, attribute) && return unless addresses.all?(&:valid_mx?)
       end
+
+      if options[:strict_mx]
+        error(record, attribute) && return unless addresses.all?(&:valid_strict_mx?)
+      end
     end
 
     def error(record, attribute)

spec/valid_email2_spec.rb

@@ -19,6 +19,10 @@ class TestUserMX < TestModel
   validates :email, 'valid_email_2/email': { mx: true }
 end
 
+class TestUserStrictMX < TestModel
+  validates :email, 'valid_email_2/email': { strict_mx: true }
+end
+
 class TestUserDisallowDisposable < TestModel
   validates :email, 'valid_email_2/email': { disposable: true }
 end
@@ -253,6 +257,23 @@ def set_whitelist
     end
   end
 
+  describe "with strict mx validation" do
+    it "is valid if mx records are found" do
+      user = TestUserStrictMX.new(email: "foo@gmail.com")
+      expect(user.valid?).to be_truthy
+    end
+
+    it "is invalid if A records are found but no mx records are found" do
+      user = TestUserStrictMX.new(email: "foo@ghs.google.com")
+      expect(user.valid?).to be_falsey
+    end
+
+    it "is invalid if no mx records are found" do
+      user = TestUserStrictMX.new(email: "foo@subdomain.gmail.com")
+      expect(user.valid?).to be_falsey
+    end
+  end
+
   describe "with dotted validation" do
     it "is valid when address does not contain dots" do
       user = TestUserDotted.new(email: "johndoe@gmail.com")