get-files: side-loading of `pkg` to avoid double fs lookups

lib/get-files.js

@@ -14,9 +14,11 @@ import IGNORED from './ignored';
  * @return {Array} comprehensive list of paths to sync
  */
 
-export default async function getFiles (path) {
+export default async function getFiles (path, pkg) {
+  if (!pkg) {
     const pkgData = await read(resolve(path, 'package.json'), 'utf8');
-  const pkg = JSON.parse(pkgData);
+    pkg = JSON.parse(pkgData);
+  }
 
   let search = (pkg.files || ['.']).concat('package.json');
   if (pkg.main) search = search.concat(pkg.main);