Install devDependencies on Heroku

Question

I would like to have Heroku build my app after I push it so that I don\'t have to push the build folder up every time I make a change. However heroku only installs the depen

Answer 1

scripts": {
  ...
  "heroku-prebuild": "npm install --only=dev"
}

This was enough for me. Thanks to PixnBits for the hint about heroku-prebuild. Also - my problem was with babel. I ended up moving babel-preset-es2015 and other presets into dependencies otherwise babel complained about presets.

Update: 8/11/2017 I've been having trouble with this. It seems like things have changed (and npm is on 5.3 now). But what I see is that the heroku-prebuild script is getting run, and then the post-install script is getting run (but I was only trying to install -dev).

So what I have been doing that works is to just run:

heroku config:set NPM_CONFIG_PRODUCTION=false

And just leave it set that way. I'd love a better solution.

Answer 2

you can use this in your build script "build": "npm install --only=dev" should in case you still want to perform more operations e.g transpiling your code with babel you can do something like this "build": "npm install --only=dev && babel src --out-dir dist --copy-files"

Answer 3

Heroku by default installs only the production dependencies, ignoring the development dependencies under devDependencies.

Setting the npm production variable to false do the trick:

heroku config:set NPM_CONFIG_PRODUCTION=false

More info are available at the Heroku Node.js Support page.

Answer 4

To unintall dependencies you need to do these

1. Update NPM_CONFIG_PRODUCTION

   heroku config variable set

   NPM_CONFIG_PRODUCTION=false

2. Add heroku-prebuild:

    scripts": {
      ...
      "heroku-prebuild": "npm install"
    }

or

    scripts": {
      ...
      "heroku-prebuild": "npm install --only=dev"
    }

Answer 5

Keeping NPM_CONFIG_PRODUCTION true, I used Heroku's script hooks:

"scripts": {
  ...
  "heroku-prebuild": "export NPM_CONFIG_PRODUCTION=false; export NODE_ENV=; NPM_CONFIG_PRODUCTION=false NODE_ENV=development npm install --only=dev --dev",
  "heroku-postbuild": "export NPM_CONFIG_PRODUCTION=true; export NODE_ENV=production;",
   ...
},

(Finally) worked for me.