title: Regex String in transform to handle .vue file in Vue
body: <p>What is the different between the regex string</p>
  <pre><code>transform: {
        &quot;^[^.]+.vue$&quot;: &quot;vue-jest&quot;,
        &quot;^.+\\.js$&quot;: &quot;babel-jest&quot;
      },
  </code></pre>
  <p>and</p>
  <pre><code>transform: {                                                     
       '^.+\\.vue$': 'vue-jest',   
       '\\.[jt]sx?$': 'babel-jest'                                     
     },
  </code></pre>
  <p>I am new to Vue and not familiar with Regex string that is use in transform in Jest.config.js to handle .vue file. Thank you in advance for answering.</p>