title: Format number - Prefer annotated tokens (like `%<foo>s`) over unannotated tokens (like `%s`) (Rubocop)
body: <p>I have this line of code which Rubocop is complaining about</p>
  
  <pre><code>offset = -7
  format('%.2i', offset)
  </code></pre>
  
  <p>Rubocop's message is</p>
  
  <blockquote>
    <p>rubocop: warning
    C - Style/FormatStringToken: Prefer annotated tokens (like <code>%&lt;foo&gt;s</code>) over unannotated tokens (like <code>%s</code>).</p>
  </blockquote>
  
  <p>But even when reading the explanations in the documentation <a href="https://www.rubydoc.info/gems/rubocop/RuboCop/Cop/Style/FormatStringToken" rel="noreferrer">https://www.rubydoc.info/gems/rubocop/RuboCop/Cop/Style/FormatStringToken</a> I cannot make it compliant.</p>
  
  <p>The goal of the code is to add a 0 whenever the <code>offset</code> is a single digit number and to not add anything when the number has two digits already.</p>
  
  <p>I tried the following:</p>
  
  <pre><code>offset = -7
  format('%.2{offset}', offset: offset)
  </code></pre>