perfect_email_regex.rb

# Shamelessly ripped from http://fightingforalostcause.net/misc/2006/compare-email-regex.php

describe "The perfect email regex" do
  before(:all) do
    @regex = /^([\w\!\#$\%\&\'\*\+\-\/\=\?\^\`{\|\}\~]+\.)*[\w\!\#$\%\&\'\*\+\-\/\=\?\^\`{\|\}\~]+@((((([a-z0-9]{1}[a-z0-9\-]{0,62}[a-z0-9]{1})|[a-z])\.)+[a-z]{2,6})|(\d{1,3}\.){3}\d{1,3}(\:\d{1,5})?)$/i
  end
  
  def matches(email)
    !!email.match(@regex)
  end
  
  def self.it_should_match(email)
    it "should be valid for #{email}" do
      matches(email).should be_true
    end
  end
  
  def self.it_should_not_match(email)
    it "should be invalid for #{email}" do
      matches(email).should be_false
    end    
  end
  
  # The following are valid emails
  it_should_match("l3tt3rsAndNumb3rs@domain.com")
  it_should_match("has-dash@domain.com")
  it_should_match("hasApostrophe.o'leary@domain.org")
  it_should_match("uncommonTLD@domain.museum")
  it_should_match("uncommonTLD@domain.travel")
  it_should_match("uncommonTLD@domain.mobi")
  it_should_match("countryCodeTLD@domain.uk")
  it_should_match("countryCodeTLD@domain.rw")
  it_should_match("lettersInDomain@911.com")
  it_should_match("underscore_inLocal@domain.net")
  it_should_match("IPInsteadOfDomain@127.0.0.1")
  it_should_match("IPAndPort@127.0.0.1:25")
  it_should_match("subdomain@sub.domain.com")
  it_should_match("local@dash-inDomain.com")
  it_should_match("dot.inLocal@foo.com")
  it_should_match("a@singleLetterLocal.org")
  it_should_match("singleLetterDomain@x.org")
  it_should_match("&*=?^+{}'~@validCharsInLocal.net")
  it_should_match("foor@bar.newTLD")
  
  # The following are invalid emails
  it_should_not_match("missingDomain@.com")
  it_should_not_match("@missingLocal.org")
  it_should_not_match("missingatSign.net")
  it_should_not_match("missingDot@com")
  it_should_not_match("two@@signs.com")
  it_should_not_match("colonButNoPort@127.0.0.1:")
  it_should_not_match("")
  it_should_not_match("someone-else@127.0.0.1.26")
  it_should_not_match(".localStartsWithDot@domain.com")
  it_should_not_match("localEndsWithDot.@domain.com")
  it_should_not_match("two..consecutiveDots@domain.com")
  it_should_not_match("domainStartsWithDash@-domain.com")
  it_should_not_match("domainEndsWithDash@domain-.com")
  it_should_not_match("numbersInTLD@domain.c0m")
  it_should_not_match("missingTLD@domain.")
  it_should_not_match("! \"()#$\%,/;<>[]`|@invalidCharsInLocal.org")
  it_should_not_match("invalidCharsInDomain@! \"()#$\%,/;<>_[]`|.org")
  it_should_not_match("local@SecondLevelDomainNamesAreInvalidIfTheyAreLongerThan64Charactersss.org")
end