javascript - How can I run multiple npm scripts in parallel?

#short
#javascript
#build
"scripts": {
"wp-server": "webpack-dev-server",
}

"dev": "npm run start-watch && npm run wp-server"

... but that will wait for start-watch to finish before running wp-server.
How can I run these in parallel? Please keep in mind that I need to see the output of these commands. Also, if your solution involves a build tool, I'd rather use gulp instead of grunt because I already use it in another project.