class RuboCop::Cop::Lint::SelfAssignment

Checks for self-assignments.

@example

# bad
foo = foo
foo, bar = foo, bar
Foo = Foo

# good
foo = bar
foo, bar = bar, foo
Foo = Bar

Constants

ASSIGNMENT_TYPE_TO_RHS_TYPE
MSG

Public Instance Methods

on_and_asgn(node)
Alias for: on_or_asgn
on_casgn(node) click to toggle source
# File lib/rubocop/cop/lint/self_assignment.rb, line 41
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_cvasgn(node)
Alias for: on_lvasgn
on_gvasgn(node)
Alias for: on_lvasgn
on_ivasgn(node)
Alias for: on_lvasgn
on_lvasgn(node) click to toggle source
# File lib/rubocop/cop/lint/self_assignment.rb, line 29
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
Also aliased as: on_ivasgn, on_cvasgn, on_gvasgn
on_masgn(node) click to toggle source
# File lib/rubocop/cop/lint/self_assignment.rb, line 49
def on_masgn(node)
  add_offense(node) if multiple_self_assignment?(node)
end
on_or_asgn(node) click to toggle source
# File lib/rubocop/cop/lint/self_assignment.rb, line 53
def on_or_asgn(node)
  lhs, rhs = *node
  add_offense(node) if rhs_matches_lhs?(rhs, lhs)
end
Also aliased as: on_and_asgn

Private Instance Methods

multiple_self_assignment?(node) click to toggle source
# File lib/rubocop/cop/lint/self_assignment.rb, line 61
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) click to toggle source
# File lib/rubocop/cop/lint/self_assignment.rb, line 71
def rhs_matches_lhs?(rhs, lhs)
  rhs.type == ASSIGNMENT_TYPE_TO_RHS_TYPE[lhs.type] &&
    rhs.children.first == lhs.children.first
end