class RuboCop::Cop::Style::CollectionCompact
hash.compact!
# good
hash.select! { |k, v| !v.nil? }
hash.reject! { |k, v| v.nil? }
hash.reject!(&:nil?)
# bad
array.compact
# good
array.select { |e| !e.nil? }
array.delete_if { |e| e.nil? }
array.reject { |e| e.nil? }
array.delete_if(&:nil?)
array.reject(&:nil?)
# bad
@example
when the receiver is a hash object.
and ‘[[1, 2], [3, nil]].compact` are not compatible. This will work fine
For example, `[[1, 2], [3, nil]].reject { |first, second| second.nil? }`
result in false positives as well.
we can’t know the type of the receiver object for sure, which may
`nil` check of block arguments to the receiver object. Additionally,
It is unsafe by default because false positives may occur in the
@safety
and hashes can be replaced with ‘{Array,Hash}#{compact,compact!}`.
Checks for places where custom logic on rejection nils from arrays
def good_method_name(node)
def good_method_name(node) if node.bang_method? 'compact!' else 'compact' end end
def offense_range(node)
def offense_range(node) if reject_method_with_block_pass?(node) range(node, node) else block_node = node.parent return unless block_node&.block_type? unless (args, receiver = reject_method?(block_node) || select_method?(block_node)) return end return unless args.last.source == receiver.source range(node, block_node) end end
def on_send(node)
def on_send(node) return unless (range = offense_range(node)) if (target_ruby_version <= 3.0 || node.method?(:delete_if)) && to_enum_method?(node) return end good = good_method_name(node) message = format(MSG, good: good, bad: range.source) add_offense(range, message: message) { |corrector| corrector.replace(range, good) } end
def range(begin_pos_node, end_pos_node)
def range(begin_pos_node, end_pos_node) range_between(begin_pos_node.loc.selector.begin_pos, end_pos_node.source_range.end_pos) end
def to_enum_method?(node)
def to_enum_method?(node) return false unless node.receiver.send_type? TO_ENUM_METHODS.include?(node.receiver.method_name) end