40 lines
1,010 B
Ruby
40 lines
1,010 B
Ruby
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module RuboCop
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module Cop
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module Gitlab
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class PredicateMemoization < RuboCop::Cop::Cop
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MSG = <<~EOL.freeze
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Avoid using `@value ||= query` inside predicate methods in order to
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properly memoize `false` or `nil` values.
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https://docs.gitlab.com/ee/development/utilities.html#strongmemoize
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EOL
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def on_def(node)
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return unless predicate_method?(node)
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select_offenses(node).each do |offense|
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add_offense(offense, location: :expression)
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end
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end
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private
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def predicate_method?(node)
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node.method_name.to_s.end_with?('?')
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end
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def or_ivar_assignment?(or_assignment)
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lhs = or_assignment.each_child_node.first
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lhs.ivasgn_type?
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end
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def select_offenses(node)
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node.each_descendant(:or_asgn).select do |or_assignment|
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or_ivar_assignment?(or_assignment)
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end
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end
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end
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end
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end
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end
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