class RuboCop::Cop::RSpec::OverwritingSetup

let!(:other) { other }
let(:baz) { baz }
let(:foo) { bar }
subject(:test) { something }
# good
let!(:foo) { baz }
let(:foo) { bar }
let(:foo) { baz }
subject(:foo) { bar }
let(:foo) { baz }
let(:foo) { bar }
# bad
@example
Checks if there is a let/subject that overwrites an existing one.

def find_duplicates(node) 

def find_duplicates(node)
  setup_expressions = Set.new
  node.each_child_node do |child|
    setup?(child) do |name|
      yield child, name unless setup_expressions.add?(name)
    end
  end
end

def on_block(node) 

def on_block(node)
  return unless example_group_with_body?(node)
  find_duplicates(node.body) do |duplicate, name|
    add_offense(
      duplicate,
      location: :expression,
      message: format(MSG, name: name)
    )
  end
end