class RuboCop::Cop::Lint::DuplicateMethods
Checks for duplicated instance (or singleton) method definitions.
@example
# bad def foo 1 end def foo 2 end
@example
# bad def foo 1 end alias foo bar
@example
# good def foo 1 end def bar 2 end
@example
# good def foo 1 end alias bar foo
Constants
- MSG
- RESTRICT_ON_SEND
Public Class Methods
new(config = nil, options = nil)
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Calls superclass method
RuboCop::Cop::Base::new
# File lib/rubocop/cop/lint/duplicate_methods.rb, line 57 def initialize(config = nil, options = nil) super @definitions = {} end
Public Instance Methods
on_alias(node)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 88 def on_alias(node) return unless (name = method_alias?(node)) return if node.ancestors.any?(&:if_type?) return if possible_dsl?(node) found_instance_method(node, name) end
on_def(node)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 62 def on_def(node) # if a method definition is inside an if, it is very likely # that a different definition is used depending on platform, etc. return if node.ancestors.any?(&:if_type?) return if possible_dsl?(node) found_instance_method(node, node.method_name) end
on_defs(node)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 71 def on_defs(node) return if node.ancestors.any?(&:if_type?) return if possible_dsl?(node) if node.receiver.const_type? _, const_name = *node.receiver check_const_receiver(node, node.method_name, const_name) elsif node.receiver.self_type? check_self_receiver(node, node.method_name) end end
on_send(node)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 103 def on_send(node) if (name = alias_method?(node)) return if node.ancestors.any?(&:if_type?) return if possible_dsl?(node) found_instance_method(node, name) elsif (attr = node.attribute_accessor?) on_attr(node, *attr) end end
Private Instance Methods
check_const_receiver(node, name, const_name)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 116 def check_const_receiver(node, name, const_name) qualified = lookup_constant(node, const_name) return unless qualified found_method(node, "#{qualified}.#{name}") end
check_self_receiver(node, name)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 123 def check_self_receiver(node, name) enclosing = node.parent_module_name return unless enclosing found_method(node, "#{enclosing}.#{name}") end
found_attr(node, args, readable: false, writable: false)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 188 def found_attr(node, args, readable: false, writable: false) args.each do |arg| name = sym_name(arg) next unless name found_instance_method(node, name) if readable found_instance_method(node, "#{name}=") if writable end end
found_instance_method(node, name)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 135 def found_instance_method(node, name) return found_sclass_method(node, name) unless (scope = node.parent_module_name) # Humanize the scope scope = scope.sub( /(?:(?<name>.*)::)#<Class:\k<name>>|#<Class:(?<name>.*)>(?:::)?/, '\k<name>.' ) scope << '#' unless scope.end_with?('.') found_method(node, "#{scope}#{name}") end
found_method(node, method_name)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 158 def found_method(node, method_name) if @definitions.key?(method_name) loc = case node.type when :def, :defs node.loc.keyword.join(node.loc.name) else node.loc.expression end message = message_for_dup(node, method_name) add_offense(loc, message: message) else @definitions[method_name] = node end end
found_sclass_method(node, name)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 148 def found_sclass_method(node, name) singleton_ancestor = node.each_ancestor.find(&:sclass_type?) return unless singleton_ancestor singleton_receiver_node = singleton_ancestor.children[0] return unless singleton_receiver_node.send_type? found_method(node, "#{singleton_receiver_node.method_name}.#{name}") end
lookup_constant(node, const_name)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 198 def lookup_constant(node, const_name) # this method is quite imperfect and can be fooled # to do much better, we would need to do global analysis of the whole # codebase node.each_ancestor(:class, :module, :casgn) do |ancestor| namespace, mod_name = *ancestor.defined_module loop do if mod_name == const_name return qualified_name(ancestor.parent_module_name, namespace, mod_name) end break if namespace.nil? namespace, mod_name = *namespace end end end
message_for_dup(node, method_name)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 130 def message_for_dup(node, method_name) format(MSG, method: method_name, defined: source_location(@definitions[method_name]), current: source_location(node)) end
on_attr(node, attr_name, args)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 174 def on_attr(node, attr_name, args) case attr_name when :attr writable = args.size == 2 && args.last.true_type? found_attr(node, [args.first], readable: true, writable: writable) when :attr_reader found_attr(node, args, readable: true) when :attr_writer found_attr(node, args, writable: true) when :attr_accessor found_attr(node, args, readable: true, writable: true) end end
possible_dsl?(node)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 230 def possible_dsl?(node) # DSL methods may evaluate a block in the context of a newly created # class or module # Assume that if a method definition is inside any block call which # we can't identify, it could be a DSL node.each_ancestor(:block).any? do |ancestor| ancestor.method_name != :class_eval && !ancestor.class_constructor? end end
qualified_name(enclosing, namespace, mod_name)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 216 def qualified_name(enclosing, namespace, mod_name) if enclosing != 'Object' if namespace "#{enclosing}::#{namespace.const_name}::#{mod_name}" else "#{enclosing}::#{mod_name}" end elsif namespace "#{namespace.const_name}::#{mod_name}" else mod_name end end
source_location(node)
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# File lib/rubocop/cop/lint/duplicate_methods.rb, line 240 def source_location(node) range = node.location.expression path = smart_path(range.source_buffer.name) "#{path}:#{range.line}" end