message: It is possible for `moduleName` to be `undefined`.
  Not sure how, but we have observed it in user storybooks.
diff: @@ -2,7 +2,9 @@ import { readJson, outputFile } from 'fs-extra';
  const dedupe = (arr) => [...new Set(arr)];
  const isUserCode = ({ name, moduleName = name }) =>
  - !moduleName.startsWith('(webpack)') && !moduleName.match(/\/(node_modules|webpack\/runtime)\//);
  + moduleName &&
  + !moduleName.startsWith('(webpack)') &&
  + !moduleName.match(/\/(node_modules|webpack\/runtime)\//);
  /**
  * Utility to trim down a `preview-stats.json` file to the bare minimum, so that it can be used to
  