Add input validation for toLong

[eritikass]

This pull request is adding input validation for toLong method as for example it is possible to only get long values from ipv4 addresses.

NB: ci tests are failing, it is because mocha deps are not compatible with older nodes anymore (and the project has no lock file)... happy to resolve in separate in a separate pull, but I see there is already few open pull that tackles that issue.

[glensc]

you forgot to add link to your mentioned pull request

[glensc]

what's the current behavior? as 0 is also valid ip (0.0.0.0), it's not correct to return wrong value because you can't parse it.

maybe more accurate is to raise an error instead?

[glensc]

what is the scenario where express returns null?

[eritikass]

@glensc - you have probably right here, this function should throw an error if the input is invalid, check code there is already at least one other function who does it also. So updated my changes, so now it throws error if not valid ipv4

[eritikass]

and there can be one more issue - ipv4 aadresses embeded into ipv6 ... in our case few examples
::ffff:192.128.24.214 or ::ffff:10.132.71.0

for those .isV4Format is false and .isV6Format is true

http://www.tcpipguide.com/free/t_IPv6IPv4AddressEmbedding.htm

[glensc]

::ffff:192.128.24.214 is ipv6 address (term is afaik ipv4 translated/mapped address 1). and the method should throw an error if you attempt to get UINT4 out of it.

hint: disable ipv6 listen in your express application (listen to ipv4_all: 0.0.0.0)

[glensc]

false, empty string '', Function ? :)

[eritikass]

I would end up testing here this .isV4Format more as in the end this will be used to validated input - so just added few possible values that can perhaps happens as bad input other than ipv6