title: Regex which include substring and not include another
body: <p>I need regex which check if string contains <code>foo</code> and not contains <code>bar</code>
  For example</p>
  
  <pre><code>foo - pass
  something only with foo - pass
  with foo and bar - fail
  without fu but bar - fail
  abracadabra - fail
  </code></pre>