"All Rights Reserved" license in package.json

According to the new npm specification you can use { "license": "UNLICENSED"} if you do not wish to grant others the right to use a private or unpublished package under any terms.

Please refer the full details here

So you might not get the error you mentioned.

According to the latest docs for package.json:

If you are using a license that hasn't been assigned an SPDX identifier, or if you are using a custom license, use the following valid SPDX expression:

{ "license" : "SEE LICENSE IN <filename>" }

Then include a file named <filename> at the top level of the package.