Resolving MX & NS Records

[gophry]

Implement message body parsing for types #31 partial implementation. MX AND NS Records.

1. function resolve() in Resolver Class now takes a type argument and defaults to A Record if none is passed.
2. Query for MX and NS records returns an array.
3. For MX queries priority is not captured in the current pull request.

[marcvdm]

I was just trying to figure out why the parser did not give me back all the nameservers. Would be much appreciated if this was to be merged.

[gophry]

Feedback appreciated.
nameservers for igor.io, facebook.com, google.com, linode.com work perfectly as sample. cross checked against dig output too.

[clue]

Thanks for the PR @gophry, I like this feature, but I'm not so sure about the current interface 👍

What does resolve() return for A records and how does this differ for other record types?

[gophry]

@clue apologies. i am under medical treatment for some time so was unavailable.
resolve() returns a string for A records and an array for NS and MX.

[clue]

No worries, there's no need to hurry these things, I hope you're alright :)

resolve() returns a string for A records and an array for NS and MX.

What's the reasoning for this? I have to admit I'm not sold on the idea of using a single method that returns a different data structure depending on an input parameter. As an alternative, does it make sense to move this to separate methods instead?

[gophry]

I was in sense not comfortable myself with the idea. but the current resolve() returns a string. it will make sense to make them as separate methods.

[clue]

FWIW, Node.js also has separate methods for each query type, for example https://nodejs.org/api/dns.html#dns_dns_resolvens_hostname_callback. Its resolve() method does in fact resolve with different types of values, I'm not sure this is something we want to do here.

[zainengineer]

any estimate on when it will be merged ?

[clue]

@gophry Thank you for your patience!

Support for NS records has been merged via #104.
Support for MX record has been merged via #106.