Buildpack

Buildpacks are responsible for transforming deployed code into a slug, which can then be executed on a dyno. Buildpacks are composed of a set of scripts, and depending on the programming language, the scripts will retrieve dependencies, output generated assets or compiled code, and more. This output is assembled into a slug by the slug compiler.

https://devcenter.heroku.com/articles/buildpacks

buildpacks are responsible for transforming an app’s source code into an executable package that is compatible with that stack.

HerokuのStack

Herokuでpackage.lockがRoot directoryにあると依存性解決をやってくれるのは、Node.jsのBuildpackが入っているから

デフォルトだと勝手に検知されるが、PHPとNode.jsの両方を使いたい、などというときには手動で追加する必要がある

https://devcenter.heroku.com/articles/buildpacks#using-multiple-buildpacks

参考：Herokuでyarnをつかう

コマンド一覧 heroku buildpacks --help

今使っているBuildpackを確認する

https://devcenter.heroku.com/articles/using-multiple-buildpacks-for-an-app#viewing-buildpacks

code:zsh

$ heroku buildpacks