class RuboCop::Cop::Lint::SelfAssignment
Checks for self-assignments.
@example
# bad foo = foo foo, bar = foo, bar Foo = Foo hash['foo'] = hash['foo'] obj.attr = obj.attr # good foo = bar foo, bar = bar, foo Foo = Bar hash['foo'] = hash['bar'] obj.attr = obj.attr2 # good (method calls possibly can return different results) hash[foo] = hash[foo]
Constants
- ASSIGNMENT_TYPE_TO_RHS_TYPE
- MSG
Public Instance Methods
on_casgn(node)
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# File lib/rubocop/cop/lint/self_assignment.rb, line 57 def on_casgn(node) lhs_scope, lhs_name, rhs = *node return unless rhs&.const_type? rhs_scope, rhs_name = *rhs add_offense(node) if lhs_scope == rhs_scope && lhs_name == rhs_name end
on_lvasgn(node)
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# File lib/rubocop/cop/lint/self_assignment.rb, line 45 def on_lvasgn(node) lhs, rhs = *node return unless rhs rhs_type = ASSIGNMENT_TYPE_TO_RHS_TYPE[node.type] add_offense(node) if rhs.type == rhs_type && rhs.source == lhs.to_s end
on_masgn(node)
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# File lib/rubocop/cop/lint/self_assignment.rb, line 65 def on_masgn(node) add_offense(node) if multiple_self_assignment?(node) end
on_or_asgn(node)
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# File lib/rubocop/cop/lint/self_assignment.rb, line 69 def on_or_asgn(node) lhs, rhs = *node add_offense(node) if rhs_matches_lhs?(rhs, lhs) end
Also aliased as: on_and_asgn
on_send(node)
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# File lib/rubocop/cop/lint/self_assignment.rb, line 36 def on_send(node) if node.method?(:[]=) handle_key_assignment(node) if node.arguments.size == 2 elsif node.assignment_method? handle_attribute_assignment(node) if node.arguments.size == 1 end end
Also aliased as: on_csend
Private Instance Methods
handle_attribute_assignment(node)
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# File lib/rubocop/cop/lint/self_assignment.rb, line 103 def handle_attribute_assignment(node) first_argument = node.first_argument return unless first_argument.respond_to?(:arguments) && first_argument.arguments.empty? if first_argument.call_type? && node.receiver == first_argument.receiver && first_argument.method_name.to_s == node.method_name.to_s.delete_suffix('=') add_offense(node) end end
handle_key_assignment(node)
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# File lib/rubocop/cop/lint/self_assignment.rb, line 92 def handle_key_assignment(node) value_node = node.arguments[1] if value_node.send_type? && value_node.method?(:[]) && node.receiver == value_node.receiver && !node.first_argument.call_type? && node.first_argument == value_node.first_argument add_offense(node) end end
multiple_self_assignment?(node)
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# File lib/rubocop/cop/lint/self_assignment.rb, line 77 def multiple_self_assignment?(node) lhs, rhs = *node return false unless rhs.array_type? return false unless lhs.children.size == rhs.children.size lhs.children.zip(rhs.children).all? do |lhs_item, rhs_item| rhs_matches_lhs?(rhs_item, lhs_item) end end
rhs_matches_lhs?(rhs, lhs)
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# File lib/rubocop/cop/lint/self_assignment.rb, line 87 def rhs_matches_lhs?(rhs, lhs) rhs.type == ASSIGNMENT_TYPE_TO_RHS_TYPE[lhs.type] && rhs.children.first == lhs.children.first end