Stack overflow doing IPAddress#as_json

[asomers]

The IPAddress gem abuses the Enumerable mixin. One example is the each method. That method will always yield at least one value, which causes problems for other Ruby code that assumes an Enumerable cannot contain itself. For example, the following snippet will trigger a stack overflow:

require 'ipaddress'
require 'active_support/json'
IPAddress.parse("1.2.3.4/32").as_json

The best solution would be to draw a distinction between an address and a network, like Python3's ipaddress module. If that were the case, then IPNetwork#each would yield a bunch of IPAddress objects, which would not implement #each.

A smaller change that wouldn't break compatibility with existing IPAddress users to be to define an as_json method which would simply call to_string.