Consider all subdomains in Ruby

FGRibreau · Mar 18, 2016 · db84501 · db84501
1 parent fa7696d
commit db84501
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Showing 3 changed files with 29 additions and 9 deletions.
diff --git a/platform/ruby/mail_checker.rb b/platform/ruby/mail_checker.rb
@@ -12,7 +12,7 @@ module MailChecker
   def self.valid?(email)
     return false unless valid_email?(email)
 
-    !BLACKLIST.include?(extract_domain(email))
+    !extract_all_domain_suffixes(email).any? { |domain| BLACKLIST.include?(domain) }
   end
 
   def self.valid_email?(email)
@@ -21,9 +21,12 @@ def self.valid_email?(email)
     email =~ EMAIL_REGEX
   end
 
-  def self.extract_domain(email)
+  def self.extract_all_domain_suffixes(email)
     domain = email.gsub(/.+@([^.]+)/, '\1').downcase
-    domain.split('.')[-2, 2].join('.') # Don't include subdomains
+
+    domain_components = domain.split('.')
+
+    (0...domain_components.length).map { |n| domain_components.drop(n).join('.') }
   end
 end
 

diff --git a/platform/ruby/mail_checker.tmpl.rb b/platform/ruby/mail_checker.tmpl.rb
@@ -12,7 +12,7 @@ module MailChecker
   def self.valid?(email)
     return false unless valid_email?(email)
 
-    !BLACKLIST.include?(extract_domain(email))
+    !extract_all_domain_suffixes(email).any? { |domain| BLACKLIST.include?(domain) }
   end
 
   def self.valid_email?(email)
@@ -21,9 +21,12 @@ def self.valid_email?(email)
     email =~ EMAIL_REGEX
   end
 
-  def self.extract_domain(email)
+  def self.extract_all_domain_suffixes(email)
     domain = email.gsub(/.+@([^.]+)/, '\1').downcase
-    domain.split('.')[-2, 2].join('.') # Don't include subdomains
+
+    domain_components = domain.split('.')
+
+    (0...domain_components.length).map { |n| domain_components.drop(n).join('.') }
   end
 end
 

diff --git a/test/platform.ruby.test.rb b/test/platform.ruby.test.rb
@@ -4,11 +4,11 @@
 
 class TestMailChecker < MiniTest::Unit::TestCase
   def valid!(email)
-    assert_equal MailChecker(email), true
+    assert_equal true, MailChecker(email)
   end
 
   def invalid!(email)
-    assert_equal MailChecker(email), false
+    assert_equal false, MailChecker(email)
   end
 
   def test_return_true_if_valid
@@ -33,7 +33,21 @@ def test_return_false_if_throwable_domain
     invalid!('ok@guerrillamailblock.com')
   end
 
+  def test_return_false_for_blacklisted_domains_and_their_subdomains
+    MailChecker::BLACKLIST.each do |blacklisted_domain|
+      invalid!("test@#{blacklisted_domain}")
+      invalid!("test@subdomain.#{blacklisted_domain}")
+      # Should not be invalid as a subdomain of a valid domain.
+      valid!("test@#{blacklisted_domain}.gmail.com")
+    end
+  end
+
   def test_can_be_called_as_regular_method
-    assert_equal MailChecker.valid?(nil), false
+    assert_equal false, MailChecker.valid?(nil)
+  end
+
+  def test_extract_all_domain_suffixes
+    expected = %w(sub.example.org example.org org)
+    assert_equal expected, MailChecker.extract_all_domain_suffixes('test@sub.example.org')
   end
 end