46 lines
1.2 KiB
Ruby
46 lines
1.2 KiB
Ruby
# frozen_string_literal: true
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module RuboCop
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module Cop
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module Performance
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class ARCountEach < RuboCop::Cop::Base
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def message(ivar)
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"If #{ivar} is AR relation, avoid `#{ivar}.count ...; #{ivar}.each... `, this will trigger two queries. " \
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"Use `#{ivar}.load.size ...; #{ivar}.each... ` instead. If #{ivar} is an array, try to use #{ivar}.size."
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end
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def_node_matcher :count_match, <<~PATTERN
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(send (ivar $_) :count)
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PATTERN
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def_node_matcher :each_match, <<~PATTERN
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(send (ivar $_) :each)
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PATTERN
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def file_name(node)
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node.location.expression.source_buffer.name
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end
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def in_haml_file?(node)
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file_name(node).end_with?('.haml.rb')
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end
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def on_send(node)
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return unless in_haml_file?(node)
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ivar_count = count_match(node)
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return unless ivar_count
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node.each_ancestor(:begin) do |begin_node|
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begin_node.each_descendant do |n|
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ivar_each = each_match(n)
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add_offense(node, message: message(ivar_count)) if ivar_each == ivar_count
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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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end
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