[BUGFIX] fix early exit

core/tasks/js.js

@@ -146,13 +146,18 @@ module.exports = class Js extends Task {
 					));
 				}
 	
-				bundler.pipe(fs.createWriteStream(_output));
+				// create the stream for writing the outFile
+				let outFile = fs.createWriteStream(_output, 'utf-8');
 				
-				bundler.on('end', () => {
+				// wait for the stream to finish writing before calling success
+				outFile.on('finish', () => {
 					browserSync.reload('*.js');
 					this._logger.success(`Written ${chalk.white(path.basename(_output))}`);
 					resolve();
 				});
+
+				// announce the write stream as a build step
+				bundler.pipe(outFile);
 			} catch(_error) {
 				this._logger.error(_error.stack);
 			}