[ruby] Correctly Handle . versus :: Syntax

[DavidBakerEffendi]

Context

When a receiver is explicitly specified in a method invocation, it may be separated from the method name using either a period (.) or two colons (::). The only difference between these two forms occurs if the method name starts with an uppercase letter. In this case, Ruby will assume that a receiver::Thing method call is actually an attempt to access a constant called Thing in the receiver unless the method invocation has a parameter list between parentheses.

• https://stackoverflow.com/questions/2276905/what-does-double-colon-mean-in-ruby

Example:

irb(main):021:0> module A
irb(main):022:1>   CONST = 0
irb(main):023:1>   def foo
irb(main):024:2>     puts "hhelo"
irb(main):025:2>   end
irb(main):026:1> end
=> :foo
irb(main):027:0> A::CONST
=> 0
irb(main):028:0> 
irb(main):029:0> A::foo
Traceback (most recent call last):
        4: from /usr/bin/irb:23:in `<main>'
        3: from /usr/bin/irb:23:in `load'
        2: from /Library/Ruby/Gems/2.6.0/gems/irb-1.0.0/exe/irb:11:in `<top (required)>'
        1: from (irb):29
NoMethodError (undefined method `foo' for A:Module)

However

irb(main):030:0> module B
irb(main):031:1>   foo = 0
irb(main):032:1> end
=> 0
irb(main):033:0> B::foo
Traceback (most recent call last):
        4: from /usr/bin/irb:23:in `<main>'
        3: from /usr/bin/irb:23:in `load'
        2: from /Library/Ruby/Gems/2.6.0/gems/irb-1.0.0/exe/irb:11:in `<top (required)>'
        1: from (irb):33
NoMethodError (undefined method `foo' for B:Module)

But

irb(main):064:0> module B
irb(main):065:1>   def self.foo
irb(main):066:2>     puts "helo"
irb(main):067:2>   end
irb(main):068:1> end
=> :foo
irb(main):069:0> B::foo
helo
=> nil

Right now we approximate all of the above as calls, which is largely fine, except in the case of the constant access.

Problem

We are not testing include as an inheritance operation, nor are we making use of the heuristic that the capitalization of the member has any significance and can instead be a simple field access.