module RuboCop::Cop::MultilineLiteralBraceLayout

def autocorrect(node) 

def autocorrect(node)
  if closing_brace_on_same_line?(node)
    lambda do |corrector|
      corrector.insert_before(node.loc.end, "\n".freeze)
    end
  else
    lambda do |corrector|
      corrector.remove(range_with_surrounding_space(node.loc.end,
                                                    :left))
      corrector.insert_after(last_element_range_with_trailing_comma(node),
                             node.loc.end.source)
    end
  end
end

def check(node) 

def check(node)
  case style
  when :symmetrical then check_symmetrical(node)
  when :new_line then check_new_line(node)
  when :same_line then check_same_line(node)
  end
end

def check_brace_layout(node) 

def check_brace_layout(node)
  return if ignored_literal?(node)
  # If the last node is or contains a conflicting HEREDOC, we don't want
  # to adjust the brace layout because this will result in invalid code.
  return if last_line_heredoc?(node.children.last)
  check(node)
end

def check_new_line(node) 

def check_new_line(node)
  return unless closing_brace_on_same_line?(node)
  add_offense(node, :end, self.class::ALWAYS_NEW_LINE_MESSAGE)
end

def check_same_line(node) 

def check_same_line(node)
  return if closing_brace_on_same_line?(node)
  add_offense(node, :end, self.class::ALWAYS_SAME_LINE_MESSAGE)
end

def check_symmetrical(node) 

def check_symmetrical(node)
  if opening_brace_on_same_line?(node)
    return if closing_brace_on_same_line?(node)
    add_offense(node, :end, self.class::SAME_LINE_MESSAGE)
  else
    return unless closing_brace_on_same_line?(node)
    add_offense(node, :end, self.class::NEW_LINE_MESSAGE)
  end
end

def children(node) 

def children(node)
  node.children
end

def closing_brace_on_same_line?(node)

against implicit and empty literals.
This method depends on the fact that we have guarded 
def closing_brace_on_same_line?(node)
  node.loc.end.line == children(node).last.loc.last_line
end

def empty_literal?(node) 

def empty_literal?(node)
  children(node).empty?
end

def ignored_literal?(node) 

def ignored_literal?(node)
  implicit_literal?(node) || empty_literal?(node) || node.single_line?
end

def implicit_literal?(node) 

def implicit_literal?(node)
  !node.loc.begin
end

def last_element_range_with_trailing_comma(node) 

def last_element_range_with_trailing_comma(node)
  trailing_comma_range = last_element_trailing_comma_range(node)
  if trailing_comma_range
    children(node).last.source_range.join(trailing_comma_range)
  else
    children(node).last.source_range
  end
end

def last_element_trailing_comma_range(node) 

def last_element_trailing_comma_range(node)
  range = range_with_surrounding_space(children(node).last.source_range,
                                       :right).end.resize(1)
  range.source == ',' ? range : nil
end

def last_line_heredoc?(node, parent = nil)

)
EOM
baz
b: <<-EOM
foo(a,
# last_line_heredoc?(node) => true
# node is `b: ...` parameter

)
}
EOM
baz
c: <<-EOM
a: 1,
b: {
foo(a,
# last_line_heredoc?(node) => false
# node is `b: ...` parameter

Example:

or on the last line of the parent node.
children, check if the node is a HEREDOC and if the HEREDOC ends below
Starting with the parent node and recursively for the parent node's 
def last_line_heredoc?(node, parent = nil)
  parent ||= node
  if node.respond_to?(:loc) &&
     node.loc.respond_to?(:heredoc_end) &&
     node.loc.heredoc_end.last_line >= parent.loc.last_line
    return true
  end
  return false unless node.respond_to?(:children)
  node.children.any? { |child| last_line_heredoc?(child, parent) }
end

def opening_brace_on_same_line?(node)

against implicit and empty literals.
This method depends on the fact that we have guarded 
def opening_brace_on_same_line?(node)
  node.loc.begin.line == children(node).first.loc.first_line
end