Feature request: Support .node-version to specify the version

[karszawa]

I'm using nodenv to handle a lot of versions of node binaries on my computer. It provides a .node-version file to change node version based on the current directory. So, I specify the local node version by .node-version as well as setup-node input in GitHub Actions.

In this case, I want to make a .node-version file the only place where the node version is notated. To achieve this, I sometimes read .node-version and provide the result to setup-node like this:

	steps:
	  - uses: actions/checkout@v1

      - name: Read .node-version
        run: echo ::set-output name=NODE_VERSION::$(cat .node-version | cut -c 2-)
        id: nvm

      - name: Setup Node.js
        uses: actions/setup-node@v2
        with:
          node-version: ${{ steps.nvm.outputs.NODE_VERSION }}

This is acceptable, but I think it is a better option for setup-node to have node-version-file as another way to specify the node version like this:

	steps:
	  - uses: actions/checkout@v1

      - name: Setup Node.js
        uses: actions/setup-node@v2-beta
        with:
          node-version-path: '.node-version' # it should be configurable for something like monorepo project which does not have .node-version on the root

I'm willing to implement this feature if the team accepts the idea. Thanks for reading my proposal 😄

[jasonkarns]

FWIW, nodenv has an action that will read the .node-version file for you specifically to enable passing that version to setup-node: https://github.com/nodenv/actions-node-version

[ruscon]

this solution is better
#239

[jasonkarns]

@ruscon what, in your opinion, makes it "better"? I personally think a version-manager agnostic implementation (using a file that isn't version-manager specific) should be preferred.

[ruscon]

@jasonkarns "better" => "generic"