class RuboCop::Cop::Lint::RedundantSafeNavigation
Checks for redundant safe navigation calls. `instance_of?`, `kind_of?`, `is_a?`, `eql?`, `respond_to?`, and `equal?` methods are checked by default. These are customizable with `AllowedMethods` option.
The `AllowedMethods` option specifies nil-safe methods, in other words, it is a method that is allowed to skip safe navigation. Note that the `AllowedMethod` option is not an option that specifies methods for which to suppress (allow) this cop's check.
In the example below, the safe navigation operator (`&.`) is unnecessary because `NilClass` has methods like `respond_to?` and `is_a?`.
@safety
This cop is unsafe, because autocorrection can change the return type of the expression. An offending expression that previously could return `nil` will be autocorrected to never return `nil`.
@example
# bad do_something if attrs&.respond_to?(:[]) # good do_something if attrs.respond_to?(:[]) # bad while node&.is_a?(BeginNode) node = node.parent end # good while node.is_a?(BeginNode) node = node.parent end # good - without `&.` this will always return `true` foo&.respond_to?(:to_a)
@example AllowedMethods: [nil_safe_method]
# bad do_something if attrs&.nil_safe_method(:[]) # good do_something if attrs.nil_safe_method(:[]) do_something if attrs&.not_nil_safe_method(:[])
Constants
- MSG
- NIL_SPECIFIC_METHODS
Public Instance Methods
on_csend(node)
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# File lib/rubocop/cop/lint/redundant_safe_navigation.rb, line 65 def on_csend(node) return unless check?(node) && allowed_method?(node.method_name) return if respond_to_nil_specific_method?(node) range = range_between(node.loc.dot.begin_pos, node.source_range.end_pos) add_offense(range) { |corrector| corrector.replace(node.loc.dot, '.') } end
Private Instance Methods
check?(node)
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# File lib/rubocop/cop/lint/redundant_safe_navigation.rb, line 75 def check?(node) parent = node.parent return false unless parent condition?(parent, node) || parent.and_type? || parent.or_type? || (parent.send_type? && parent.negation_method?) end
condition?(parent, node)
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# File lib/rubocop/cop/lint/redundant_safe_navigation.rb, line 85 def condition?(parent, node) (parent.conditional? || parent.post_condition_loop?) && parent.condition == node end