parseValues fails on long numbers

[mlarcher]

The parseValues option of .env method doesn't return the expected value on long numbers (greater than Number.MAX_SAFE_INTEGER).
For example, '123456123456123456', will return 123456123456123460.
This is due to javascript handling and not nconf.

To prevent this kind of problems, wouldn't it be a good thing to make sure that a numeric like env variable can be cast back to its original string value ?
i.e. in

nconf/lib/nconf/common.js

Line 134 in b9321b2

val = JSON.parse(value);

do something like:

common.parseValues = function (value) {
  var val = value;
  
  try {
    const castValue = JSON.parse(value);
    if (JSON.stringify(castValue) !== value) {
      throw "ignored";
    }
    val = castValue;
  } catch (ignore) {
    // Check for any other well-known strings that should be "parsed"
    if (value === 'undefined'){
      val = void 0;
    }
  }

  return val;
};

What do you think ?

[mhamann]

Looks like a decent proposal. Submit a PR with tests ;-)