class RuboCop::Cop::Style::SafeNavigationChainLength

Enforces safe navigation chains length to not exceed the configured maximum. The longer the chain is, the harder it becomes to track what on it could be returning ‘nil`.

There is a potential interplay with ‘Style/SafeNavigation` - if both are enabled and their settings are “incompatible”, one of the cops will complain about what the other proposes.

E.g. if ‘Style/SafeNavigation` is configured with `MaxChainLength: 2` (default) and this cop is configured with `Max: 1`, then for `foo.bar.baz if foo` the former will suggest `foo&.bar&.baz`, which is an offense for the latter.

@example Max: 2 (default)

# bad
user&.address&.zip&.upcase

# good
user&.address&.zip
user.address.zip if user

Constants

MSG

Public Instance Methods

on_csend(node) click to toggle source
# File lib/rubocop/cop/style/safe_navigation_chain_length.rb, line 29
def on_csend(node)
  safe_navigation_chains = safe_navigation_chains(node)
  return if safe_navigation_chains.size < max

  add_offense(safe_navigation_chains.last, message: format(MSG, max: max))
end

Private Instance Methods

max() click to toggle source
# File lib/rubocop/cop/style/safe_navigation_chain_length.rb, line 46
def max
  cop_config['Max'] || 2
end
safe_navigation_chains(node) click to toggle source
# File lib/rubocop/cop/style/safe_navigation_chain_length.rb, line 38
def safe_navigation_chains(node)
  node.each_ancestor.with_object([]) do |parent, chains|
    break chains unless parent.csend_type?

    chains << parent
  end
end