73 lines
2.0 KiB
Ruby
73 lines
2.0 KiB
Ruby
# typed: true
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# frozen_string_literal: true
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module RuboCop
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module Cop
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module Homebrew
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# Checks for code that can be simplified using `Object#blank?`.
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#
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# NOTE: Auto-correction for this cop is unsafe because `' '.empty?` returns `false`,
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# but `' '.blank?` returns `true`. Therefore, auto-correction is not compatible
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# if the receiver is a non-empty blank string.
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#
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# ### Example
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#
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# ```ruby
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# # bad
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# foo.nil? || foo.empty?
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# foo == nil || foo.empty?
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#
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# # good
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# foo.blank?
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# ```
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class Blank < Base
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extend AutoCorrector
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MSG = "Use `%<prefer>s` instead of `%<current>s`."
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# `(send nil $_)` is not actually a valid match for an offense. Nodes
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# that have a single method call on the left hand side
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# (`bar || foo.empty?`) will blow up when checking
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# `(send (:nil) :== $_)`.
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def_node_matcher :nil_or_empty?, <<~PATTERN
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(or
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{
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(send $_ :!)
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(send $_ :nil?)
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(send $_ :== nil)
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(send nil :== $_)
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}
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{
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(send $_ :empty?)
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(send (send (send $_ :empty?) :!) :!)
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}
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)
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PATTERN
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def on_or(node)
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nil_or_empty?(node) do |var1, var2|
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return if var1 != var2
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message = format(MSG, prefer: replacement(var1), current: node.source)
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add_offense(node, message:) do |corrector|
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autocorrect(corrector, node)
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end
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end
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end
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private
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def autocorrect(corrector, node)
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variable1, _variable2 = nil_or_empty?(node)
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range = node.source_range
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corrector.replace(range, replacement(variable1))
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end
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def replacement(node)
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node.respond_to?(:source) ? "#{node.source}.blank?" : "blank?"
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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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