title: Mock all except one function in a module
body: <p>I am testing <code>fileA.js</code>, which requires <code>fileB.js</code></p>
  
  <p>In <code>fileA.test.js</code>, I wish to mock all methods from <code>fileB.js</code> except one.</p>
  
  <p>In <code>fileA.test.js</code> I have:</p>
  
  <pre><code>const common = require("../src/fileB");
  jest.mock("../src/fileB");
  </code></pre>
  
  <p>There is one method I do not wish to be mocked. Is this sort of thing possible in nodeJS? </p>
  
  <p>Thank you. </p>