Breaks with uglifyjs-webpack-plugin

[smoosh911]

Error: ERROR in bundle-auth.js from UglifyJs
Unexpected token: punc ()) [./node_modules/json-schema-faker/dist/index.umd.min.js:6,1852][bundle-auth.js:141,1603]

Commands ran:
npm install
npm run build ("build": webpack)

Versions:
"uglifyjs-webpack-plugin": "^1.3.0" (I've tried multiple versions
"sway": "^2.0.6" (tried multiple versions)