class RuboCop::Cop::Naming::ConstantName

INCH_IN_CM = 2.54
# good
Inch_In_Cm = 2.54
INCHinCM = 2.54
InchInCm = 2.54
# bad
@example
for certain the type of value that would be assigned to a constant.
To avoid false positives, it ignores cases in which we cannot know
SCREAMING_SNAKE_CASE.
This cop checks whether constant names are written using

def allowed_assignment?(value) 

def allowed_assignment?(value)
  value && %i[block const casgn].include?(value.type) ||
    allowed_method_call_on_rhs?(value) ||
    class_or_struct_return_method?(value) ||
    allowed_conditional_expression_on_rhs?(value)
end

def allowed_conditional_expression_on_rhs?(node) 

def allowed_conditional_expression_on_rhs?(node)
  node&.if_type? && contains_contant?(node)
end

def allowed_method_call_on_rhs?(node) 

def allowed_method_call_on_rhs?(node)
  node&.send_type? &&
    (node.receiver.nil? || !literal_receiver?(node))
end

def contains_contant?(node) 

def contains_contant?(node)
  node.branches.any?(&:const_type?)
end

def on_casgn(node) 

def on_casgn(node)
  if node.parent&.or_asgn_type?
    lhs, value = *node.parent
    _scope, const_name = *lhs
  else
    _scope, const_name, value = *node
  end
  # We cannot know the result of method calls like
  # NewClass = something_that_returns_a_class
  # It's also ok to assign a class constant another class constant,
  # `Class.new(...)` or `Struct.new(...)`
  # SomeClass = SomeOtherClass
  # SomeClass = Class.new(...)
  # SomeClass = Struct.new(...)
  return if allowed_assignment?(value)
  return if SNAKE_CASE.match?(const_name)
  add_offense(node.loc.name)
end