class RuboCop::Cop::Style::Alias
This cop finds uses of `alias` where `alias_method` would be more appropriate (or is simply preferred due to configuration), and vice versa. It also finds uses of `alias :symbol` rather than `alias bareword`.
Constants
- MSG_ALIAS
- MSG_ALIAS_METHOD
- MSG_SYMBOL_ARGS
Public Instance Methods
autocorrect(node)
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# File lib/rubocop/cop/style/alias.rb, line 42 def autocorrect(node) if node.send_type? correct_alias_method_to_alias(node) elsif scope_type(node) == :dynamic || style == :prefer_alias_method correct_alias_to_alias_method(node) else correct_alias_with_symbol_args(node) end end
on_alias(node)
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# File lib/rubocop/cop/style/alias.rb, line 26 def on_alias(node) # alias_method can't be used with global variables return if node.children.any?(&:gvar_type?) if scope_type(node) == :dynamic || style == :prefer_alias_method add_offense(node, :keyword, MSG_ALIAS) elsif node.children.none? { |arg| bareword?(arg) } existing_args = node.children.map(&:source).join(' ') preferred_args = node.children.map { |a| a.source[1..-1] }.join(' ') arg_ranges = node.children.map(&:source_range) msg = format(MSG_SYMBOL_ARGS, preferred_args, existing_args) add_offense(node, arg_ranges.reduce(&:join), msg) end end
on_send(node)
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# File lib/rubocop/cop/style/alias.rb, line 17 def on_send(node) return unless node.method_name == :alias_method && node.receiver.nil? return if style == :prefer_alias_method return if scope_type(node) == :dynamic msg = format(MSG_ALIAS_METHOD, lexical_scope_type(node)) add_offense(node, :selector, msg) end
Private Instance Methods
bareword?(sym_node)
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# File lib/rubocop/cop/style/alias.rb, line 77 def bareword?(sym_node) sym_node.source[0] != ':' end
correct_alias_method_to_alias(node)
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# File lib/rubocop/cop/style/alias.rb, line 81 def correct_alias_method_to_alias(node) lambda do |corrector| new, old = *node.method_args replacement = "alias #{new.children.first} #{old.children.first}" corrector.replace(node.source_range, replacement) end end
correct_alias_to_alias_method(node)
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# File lib/rubocop/cop/style/alias.rb, line 89 def correct_alias_to_alias_method(node) lambda do |corrector| new, old = *node replacement = "alias_method :#{new.children.first}, " ":#{old.children.first}" corrector.replace(node.source_range, replacement) end end
correct_alias_with_symbol_args(node)
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# File lib/rubocop/cop/style/alias.rb, line 98 def correct_alias_with_symbol_args(node) lambda do |corrector| new, old = *node corrector.replace(new.source_range, new.children.first.to_s) corrector.replace(old.source_range, old.children.first.to_s) end end
lexical_scope_type(node)
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# File lib/rubocop/cop/style/alias.rb, line 70 def lexical_scope_type(node) node.each_ancestor(:class, :module) do |ancestor| return ancestor.class_type? ? 'in a class body' : 'in a module body' end 'at the top level' end
scope_type(node)
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In this expression, will `self` be the same as the innermost enclosing class or module block (:lexical)? Or will it be something else (:dynamic)?
# File lib/rubocop/cop/style/alias.rb, line 57 def scope_type(node) while (parent = node.parent) case parent.type when :class, :module return :lexical when :def, :defs, :block return :dynamic end node = parent end :lexical end