support for license (singular)

[pdehaan]

Steps to reproduce:

1. On http://package-json-validator.com/ enter the URL: https://github.com/isaacs/node-tap

Actual results:

{
  "valid": false,
  "errors": [
    "Type for field license, was expected to be string, not object",
    "Type for field repository, was expected to be object, not string"
  ],
  "warnings": [
    "Missing recommended field: bugs"
  ],
  "recommendations": [
    "Missing optional field: homepage"
  ]
}

Expected results:

We should support the singular version of license. I figure @isaacs knows a thing or two about package.json and license is valid. I found https://www.npmjs.org/doc/files/package.json.html#license but it only mentions the shorthand version of the license as a strong, not as an object. And makes no mention of licenses[] plural.

[pdehaan]

Not sure about the repository error. I cant find a definitive answer on https://www.npmjs.org/doc/files/package.json.html#repository as that only lists the object form and not the string form (and doesn't mention the shorthand for github of :user/:repo at all).

I'm not sure how accurate the npm docs are, honestly. I don't know if there is a more definitive place to get answers on what is and isn't allowed and what are the latest formats.

[JoshuaKGoldberg]

Looks like license (singular) has since been given support, so I'm going to go ahead and close this out as resolved. Cheers! 🧡

As for repository, the shorthand string is now deprecated in favor of the full object: npm/cli#7299 (comment)