Node.js now installs `devDependencies` by default

Change effective on 01 March 2018

Many users getting started with Node.js on Heroku run a build step with webpack, ng-cli, or another build tool only to find that it’s in their devDependencies and therefore not installed by default on Heroku.

We’ve updated the default behavior to install all dependencies listed in package.json during build, and to strip out the developer dependencies before the app is deployed.

Visit Dev Center to learn how you can customize this behavior

You will see a new section in your logs where we prune the devDependencies:

$ git push heroku master
...
-----> Pruning devDependencies
       removed 24 packages in 0.241s
...