Class: RuboCop::Cop::Lint::Void

# File 'lib/rubocop/cop/lint/void.rb', line 321

def all_values_entirely_literal?(node)
  node.each_value.all? { |value| entirely_literal?(value) }
end

# File 'lib/rubocop/cop/lint/void.rb', line 298

def autocorrect_nonmutating_send(corrector, node, suggestion)
  send_node = node.call_type? ? node : node.send_node

  corrector.replace(send_node.loc.selector, suggestion)
end

# File 'lib/rubocop/cop/lint/void.rb', line 280

def autocorrect_void_expression(corrector, node)
  # Referencing a constant can trigger autoloading side effects (e.g. forcing a file
  # to load before a monkey-patch), so removing it may change behavior. Flag but don't
  # autocorrect, leaving it to the user.
  return if node.const_type? && !node.special_keyword?
  return if node.parent.type?(:if, :case, :when, :case_match, :in_pattern)
  return if (def_node = node.each_ancestor(:any_def).first) && def_node.assignment_method?

  range = range_with_surrounding_space(range: void_expression_range(node), side: :left)
  corrector.remove(range)
end

# File 'lib/rubocop/cop/lint/void.rb', line 267

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

# File 'lib/rubocop/cop/lint/void.rb', line 113

def check_begin(node)
  expressions = *node
  inside_each_block = node.each_ancestor(:any_block).first&.method?(:each)
  expressions.pop if !in_void_context?(node) || inside_each_block || setter_method?(node)
  expressions.each do |expr|
    check_void_op(expr) { inside_each_block }
    check_expression(expr)
  end
end

# File 'lib/rubocop/cop/lint/void.rb', line 145

def check_case_expression(case_node)
  case_node.each_when { |when_node| check_expression(when_node.body) if when_node.body }
  check_expression(case_node.else_branch) if case_node.else_branch
end

# File 'lib/rubocop/cop/lint/void.rb', line 150

def check_case_match_expression(case_node)
  case_node.each_in_pattern do |in_pattern_node|
    check_expression(in_pattern_node.body) if in_pattern_node.body
  end
  check_expression(case_node.else_branch) if case_node.else_branch
end

# File 'lib/rubocop/cop/lint/void.rb', line 248

def check_ensure(node)
  return unless (body = node.branch)
  # NOTE: the `begin` node case is already handled via `on_begin`
  return if body.begin_type?

  check_expression(body)
end

# File 'lib/rubocop/cop/lint/void.rb', line 123

def check_expression(expr)
  return check_if_expression(expr) if expr.if_type?
  return check_case_expression(expr) if expr.case_type?
  return check_case_match_expression(expr) if expr.case_match_type?

  check_void_expression_nodes(expr)
end

# File 'lib/rubocop/cop/lint/void.rb', line 141

def check_if_expression(if_node)
  check_void_expression_nodes(if_node.body) if if_node.body
end

# File 'lib/rubocop/cop/lint/void.rb', line 202

def check_literal(node)
  if !entirely_literal?(node) || node.xstr_type? || node.range_type? || node.nil_type?
    return
  end

  add_offense(node, message: format(LIT_MSG, lit: node.source)) do |corrector|
    next if node.each_descendant(:begin).any?

    autocorrect_void_expression(corrector, node)
  end
end

# File 'lib/rubocop/cop/lint/void.rb', line 230

def check_nonmutating(node)
  return unless node.type?(:call, :any_block)

  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

# File 'lib/rubocop/cop/lint/void.rb', line 214

def check_self(node)
  return unless node.self_type?

  add_offense(node, message: SELF_MSG) do |corrector|
    autocorrect_void_expression(corrector, node)
  end
end

# File 'lib/rubocop/cop/lint/void.rb', line 184

def check_var(node)
  return unless node.variable? || node.const_type?

  if node.const_type?
    template = node.special_keyword? ? VAR_MSG : CONST_MSG

    offense_range = node
    message = format(template, var: node.source)
  else
    offense_range = node.loc.name
    message = format(VAR_MSG, var: node.loc.name.source)
  end

  add_offense(offense_range, message: message) do |corrector|
    autocorrect_void_expression(corrector, node)
  end
end

# File 'lib/rubocop/cop/lint/void.rb', line 222

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

# File 'lib/rubocop/cop/lint/void.rb', line 131

def check_void_expression_nodes(expr)
  check_literal(expr)
  check_var(expr)
  check_self(expr)
  check_void_expression(expr)
  return unless cop_config['CheckForMethodsWithNoSideEffects']

  check_nonmutating(expr)
end

# File 'lib/rubocop/cop/lint/void.rb', line 158

def check_void_op(node, &block)
  node = node.children.first while node&.begin_type?
  return unless node&.call_type? && OPERATORS.include?(node.method_name)
  return unless operation?(node)

  return if block && yield(node)

  add_offense(node.loc.selector,
              message: format(OP_MSG, op: node.method_name)) do |corrector|
    autocorrect_void_op(corrector, node)
  end
end

# File 'lib/rubocop/cop/lint/void.rb', line 304

def entirely_literal?(node)
  case node.type
  when :array
    all_values_entirely_literal?(node)
  when :hash
    all_keys_entirely_literal?(node) && all_values_entirely_literal?(node)
  when :send, :csend
    node.method?(:freeze) && node.receiver && entirely_literal?(node.receiver)
  else
    node.literal?
  end
end

# File 'lib/rubocop/cop/lint/void.rb', line 256

def in_void_context?(node)
  parent = node.parent
  return false unless parent && parent.children.last == node

  parent.respond_to?(:void_context?) && parent.void_context?
end

# File 'lib/rubocop/cop/lint/void.rb', line 102

def on_begin(node)
  check_begin(node)
end

# File 'lib/rubocop/cop/lint/void.rb', line 91

def on_block(node)
  return unless node.body && !node.body.begin_type?
  return unless in_void_context?(node.body)
  return if node.method?(:each)

  check_void_op(node.body)
  check_expression(node.body)
end

# File 'lib/rubocop/cop/lint/void.rb', line 107

def on_ensure(node)
  check_ensure(node)
end

# File 'lib/rubocop/cop/lint/void.rb', line 100

alias on_itblock on_block

# File 'lib/rubocop/cop/lint/void.rb', line 105

alias on_kwbegin on_begin

# File 'lib/rubocop/cop/lint/void.rb', line 99

alias on_numblock on_block

# File 'lib/rubocop/cop/lint/void.rb', line 171

def operation?(node)
  return UNARY_OPERATORS.include?(node.method_name) || !node.loc.dot if node.arguments.none?
  return false if !node.arguments.one? || trailing_comma?(node)

  argument = node.first_argument

  argument.hash_type? ? argument.braces? : !argument.type?(*NON_VALUE_ARGUMENT_TYPES)
end

# File 'lib/rubocop/cop/lint/void.rb', line 263

def setter_method?(node)
  node.parent&.any_def_type? && node.parent.assignment_method?
end

# File 'lib/rubocop/cop/lint/void.rb', line 180

def trailing_comma?(node)
  node.last_argument.source_range.end.join(node.source_range.end).source.include?(',')
end

# File 'lib/rubocop/cop/lint/void.rb', line 292

def void_expression_range(node)
  return node.source_range unless node.respond_to?(:heredoc?) && node.heredoc?

  node.source_range.join(node.loc.heredoc_end)
end