False positive of Instance Variable Assumption with Struct initialize overload

[ryym]

Hi, I found an issue about Instance Variable Assumption that occurs when a class have a Struct with its own initialize method in its block.

Example code:

class Foo
  Bar = Struct.new(:a) do
    def initialize(a)
      super
      p 'bar created'
    end
  end

  def initialize
    @foo = :foo
  end

  def foo?
    @foo == :foo
  end
end

When I run reek against this file, Reek reports a warning of Instance Variable Assumption, even though @foo in Foo class is initialized correctly.

[1]:InstanceVariableAssumption: Foo assumes too much for instance variable '@foo' [https://github.com/troessner/reek/blob/v5.4.0/docs/Instance-Variable-Assumption.md]

It looks like the cause is Bar which has a block containing an initialize method.
I confirmed that Reek did not warn if:

• Bar does not have an initialize method.
• Bar is defined by normal class syntax (class Bar ... end).
• Bar is defined after the initialize method of Foo.

Similar issue: #1137

[troessner]

Oh, good catch! Yes, that definitely looks like a bug on our side. Thank you for that detailed report, we will look into this (not sure when though).