Return when done (#173)

lib/index.js

@@ -109,7 +109,7 @@ module.exports = options => (files, metalsmith, done) => {
 
   // Check whether the pattern option is valid
   if (!(typeof settings.pattern === 'string' || Array.isArray(settings.pattern))) {
-    done(
+    return done(
       new Error(
         'invalid pattern, the pattern option should be a string or array of strings. See https://www.npmjs.com/package/metalsmith-layouts#pattern'
       )
@@ -124,18 +124,19 @@ module.exports = options => (files, metalsmith, done) => {
 
   // Let the user know when there are no files to process, unless the check is suppressed
   if (validFiles.length === 0) {
-    const msg =
+    const message =
       'no files to process. See https://www.npmjs.com/package/metalsmith-layouts#no-files-to-process';
+
     if (settings.suppressNoFilesError) {
-      debug(msg);
-      done();
-    } else {
-      done(new Error(msg));
+      debug(message);
+      return done();
     }
+
+    return done(new Error(message));
   }
 
   // Map all files that should be processed to an array of promises and call done when finished
-  Promise.all(
+  return Promise.all(
     validFiles.map(filename => render({ filename, files, metadata, settings, metalsmith }))
   )
     .then(() => done())