Leverage more node extensions

[Drenmi]

This change makes our InternalAffairs/NodeDestructuring a bit more picky. Before, it accepted splat destructuring, e.g.:

receiver, method_name, arguments = send_node

but with this change, it enforces the use of node extension methods for all use cases.

I hope to use this to guide me in adding more node extensions.

This change already comes with a slew of fixes where existing node extensions could be used in place of splat destructuring.

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[bbatsov]

Great work! 🙇

[bbuchalter]

@Drenmi I'm trying to make some custom cops comply with this new rule, but I'm not familiar with node extensions. I don't see anything about it on the README or the wiki. Same examples:

option_node, value_node = *node
name, args, = *node
_name, superclass, _body = *node

Based on the message I see from Rubocop, I tried changing to this shape:

option_node = node.option_node
value_node = node.value_node

But I get errors like this:

undefined method `option_node' for #<RuboCop::AST::PairNode:0x007f80342d84d8>

Could you please advise?

[Drenmi]

@bbuchalter You can find documentation for the node extension decorators in RubyDoc.

For example, if you have a PairNode, you can do node.key and node.value. (Provided by HashElementNode.)

If you have a SendNode, you can do node.method_name and node.arguments.

Etc.

Note that we don't have node extensions for all node types yet, but I'm working on it.