class RuboCop::Cop::Lint::Void

end
do_something(some_array)
some_array.sort!
def some_method(some_array)
end
some_var
do_something
def some_method(some_var)
end
some_num * 10
do_something
def some_method
# good
end
do_something(some_array)
some_array.sort
def some_method(some_array)
# bad
@example CheckForMethodsWithNoSideEffects: true
end
do_something
some_var
def some_method(some_var)
end
do_something
some_num * 10
def some_method
# bad
@example CheckForMethodsWithNoSideEffects: false (default)
methods used in void context.
Checks for operators, variables, literals, lambda, proc and nonmutating

def autocorrect_nonmutating_send(corrector, node, suggestion) 

def autocorrect_nonmutating_send(corrector, node, suggestion)
  send_node = if node.send_type?
                node
              else
                node.send_node
              end
  corrector.replace(send_node.loc.selector, suggestion)
end

def autocorrect_void_expression(corrector, node) 

def autocorrect_void_expression(corrector, node)
  corrector.remove(range_with_surrounding_space(range: node.source_range, side: :left))
end

def autocorrect_void_op(corrector, node) 

def autocorrect_void_op(corrector, node)
  if node.arguments.empty?
    corrector.replace(node, node.receiver.source)
  else
    corrector.replace(
      range_with_surrounding_space(range: node.loc.selector, side: :both,
                                   newlines: false),
      "\n"
    )
  end
end

def check_begin(node) 

def check_begin(node)
  expressions = *node
  expressions.pop unless in_void_context?(node)
  expressions.each { |expr| check_expression(expr) }
end

def check_expression(expr) 

def check_expression(expr)
  check_void_op(expr)
  check_literal(expr)
  check_var(expr)
  check_self(expr)
  check_void_expression(expr)
  return unless cop_config['CheckForMethodsWithNoSideEffects']
  check_nonmutating(expr)
end

def check_literal(node) 

def check_literal(node)
  return if !node.literal? || node.xstr_type? || node.range_type?
  add_offense(node, message: format(LIT_MSG, lit: node.source)) do |corrector|
    autocorrect_void_expression(corrector, node)
  end
end

def check_nonmutating(node) 

def check_nonmutating(node)
  return if !node.send_type? && !node.block_type? && !node.numblock_type?
  method_name = node.method_name
  return unless NONMUTATING_METHODS.include?(method_name)
  suggestion = if METHODS_REPLACEABLE_BY_EACH.include?(method_name)
                 'each'
               else
                 "#{method_name}!"
               end
  add_offense(node,
              message: format(NONMUTATING_MSG, method: method_name,
                                               suggest: suggestion)) do |corrector|
    autocorrect_nonmutating_send(corrector, node, suggestion)
  end
end

def check_self(node) 

def check_self(node)
  return unless node.self_type?
  add_offense(node, message: SELF_MSG) do |corrector|
    autocorrect_void_expression(corrector, node)
  end
end

def check_var(node) 

def check_var(node)
  return unless node.variable? || node.const_type?
  if node.const_type? && node.special_keyword?
    add_offense(node, message: format(VAR_MSG, var: node.source)) do |corrector|
      autocorrect_void_expression(corrector, node)
    end
  else
    add_offense(node.loc.name,
                message: format(VAR_MSG, var: node.loc.name.source)) do |corrector|
      autocorrect_void_expression(corrector, node)
    end
  end
end

def check_void_expression(node) 

def check_void_expression(node)
  return unless node.defined_type? || node.lambda_or_proc?
  add_offense(node, message: format(EXPRESSION_MSG, expression: node.source)) do |corrector|
    autocorrect_void_expression(corrector, node)
  end
end

def check_void_op(node) 

def check_void_op(node)
  return unless node.send_type? && OPERATORS.include?(node.method_name)
  add_offense(node.loc.selector,
              message: format(OP_MSG, op: node.method_name)) do |corrector|
    autocorrect_void_op(corrector, node)
  end
end

def in_void_context?(node) 

def in_void_context?(node)
  parent = node.parent
  return false unless parent && parent.children.last == node
  VOID_CONTEXT_TYPES.include?(parent.type) && parent.void_context?
end

def on_begin(node) 

def on_begin(node)
  check_begin(node)
end

def on_block(node) 

def on_block(node)
  return unless node.body && !node.body.begin_type?
  return unless in_void_context?(node.body)
  check_expression(node.body)
end