32 lines
955 B
Ruby
32 lines
955 B
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 ReadlinesEach < RuboCop::Cop::Base
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extend RuboCop::Cop::AutoCorrector
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MESSAGE = 'Avoid `IO.readlines.each`, since it reads contents into memory in full. ' \
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'Use `IO.each_line` or `IO.each` instead.'
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def_node_matcher :full_file_read_via_class?, <<~PATTERN
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(send
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(send (const nil? {:IO :File}) :readlines _) :each)
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PATTERN
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def_node_matcher :full_file_read_via_instance?, <<~PATTERN
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(... (... :readlines) :each)
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PATTERN
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def on_send(node)
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return unless full_file_read_via_class?(node) || full_file_read_via_instance?(node)
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add_offense(node.loc.selector, message: MESSAGE) do |corrector|
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corrector.replace(node.loc.expression, node.source.gsub('readlines.each', 'each_line'))
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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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