Nevermind, it kinda worked but the console outputs this:
[11:28:49] Starting 'bundlejs'...
[11:28:49]
/Users/Mistwalker/Desktop/gurupu/src/js/app.js
10:18 error Parsing error: Unexpected token {
✖ 1 problem (1 error, 0 warnings)
stream.js:74
throw er; // Unhandled stream error in pipe.
^
GulpUglifyError: unable to minify JavaScript
at createError (/Users/Mistwalker/Desktop/gurupu/node_modules/gulp-uglify/lib/create-error.js:6:14)
at wrapper (/Users/Mistwalker/Desktop/gurupu/node_modules/gulp-uglify/node_modules/lodash/_createHybrid.js:87:15)
at trycatch (/Users/Mistwalker/Desktop/gurupu/node_modules/gulp-uglify/minifier.js:26:12)
at DestroyableTransform.minify [as _transform] (/Users/Mistwalker/Desktop/gurupu/node_modules/gulp-uglify/minifier.js:79:19)
at DestroyableTransform.Transform._read (/Users/Mistwalker/Desktop/gurupu/node_modules/through2/node_modules/readable-stream/lib/_stream_transform.js:159:10)
at DestroyableTransform.Transform._write (/Users/Mistwalker/Desktop/gurupu/node_modules/through2/node_modules/readable-stream/lib/_stream_transform.js:147:83)
at doWrite (/Users/Mistwalker/Desktop/gurupu/node_modules/through2/node_modules/readable-stream/lib/_stream_writable.js:338:64)
at writeOrBuffer (/Users/Mistwalker/Desktop/gurupu/node_modules/through2/node_modules/readable-stream/lib/_stream_writable.js:327:5)
at DestroyableTransform.Writable.write (/Users/Mistwalker/Desktop/gurupu/node_modules/through2/node_modules/readable-stream/lib/_stream_writable.js:264:11)
at DestroyableTransform.ondata (stream.js:31:26)