fix: Faker::Internet.username should not generate duplicated punctuation (#2970)

* `Faker::Internet.username` should not generate duplicated punctuation

* test: Reject duplicated punctuation

Author: thdaraujo

lib/faker/default/internet.rb

@@ -65,7 +65,7 @@ def username(specifier: nil, separators: %w[. _])
         with_locale(:en) do
           case specifier
           when ::String
-            names = specifier&.gsub("'", '')&.split
+            names = specifier.gsub("'", '').scan(/[[:word:]]+/)
             shuffled_names = shuffle(names)
 
             return shuffled_names.join(sample(separators)).downcase

test/faker/default/test_faker_internet.rb

@@ -44,6 +44,22 @@ def test_email_with_apostrophes
     end
   end
 
+  def test_email_with_abbreviations
+    name = 'Mr. Faker'
+
+    deterministically_verify -> { @tester.email(name: name) } do |email|
+      assert_email_regex 'Mr', 'Faker', email
+    end
+  end
+
+  def test_email_against_name_generator
+    deterministically_verify -> { @tester.email(name: Faker::Name.unique.name) } do |email|
+      # reject emails with duplicated punctuation
+      # e.g.: "[email protected]"
+      refute_match(/[\p{Punct}]{2,}/, email)
+    end
+  end
+
   def test_email_with_separators
     deterministically_verify -> { @tester.email(name: 'jane doe', separators: '+') } do |result|
       name, domain = result.split('@')