Heroku deploy a sub directory?

Heroku requires a package.json and a lockfile in the root of the repository or they will fail the deploy.

However you can set up a package.json in the root of the repo which installs dependencies for the subdirectories and runs their related commands.

Using yarn for example, in your case you could put an empty yarn.lock in the root and a package.json like:

{
  "name": "my-project",
  "version": "0.1.0",
  "private": true,
  "scripts": {
    "postinstall": "yarn --cwd server --production=false install",
    "build": "yarn --cwd server serve"
  }
}

The --production=false ensures that devDependencies will be installed, which otherwise wouldn't happen since NODE_ENV is set to production in Heroku's environment.

I think git-subtree should work:

git subtree push --prefix server heroku master

Additional resources:

• How can I deploy/push only a subdirectory of my git repo to Heroku?
• https://coderwall.com/p/ssxp5q

Alternatively, you can use git subtree to create a heroku branch on GitHub:

git subtree push --prefix server origin heroku

which you can then deploy to Heroku using a Heroku Button. Just add an app.json and a README.md with the button to your server directory:

[![Deploy](https://www.herokucdn.com/deploy/button.png)](https://heroku.com/deploy)

and let Heroku take care of the rest.