Method: YARD::Handlers::Ruby::ClassConditionHandler#parse_condition

Defined in:
lib/yard/handlers/ruby/class_condition_handler.rb

#parse_condition ⇒ true, ... (protected)

Parses the condition part of the if/unless statement

Returns:

  • (true, false, nil) —

    true if the condition can be definitely parsed to true, false if not, and nil if the condition cannot be parsed with certainty (it’s dynamic)



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# File 'lib/yard/handlers/ruby/class_condition_handler.rb', line 36

def parse_condition
  condition = nil

  # Right now we can handle very simple unary conditions like:
  #   if true
  #   if false
  #   if 0
  #   if 100 (not 0)
  #   if defined? SOME_CONSTANT
  #
  # The last case will do a lookup in the registry and then one
  # in the Ruby world (using eval).
  case statement.condition.type
  when :int
    condition = statement.condition[0] != "0"
  when :defined
    # defined? keyword used, let's see if we can look up the name
    # in the registry, then we'll try using Ruby's powers. eval() is not
    # *too* dangerous here since code is not actually executed.
    arg = statement.condition.first

    if arg.type == :var_ref
      name = arg.source
      obj = YARD::Registry.resolve(namespace, name, true)

      begin
        condition = true if obj || (name && Object.instance_eval("defined? #{name}"))
      rescue SyntaxError, NameError
        condition = false
      end
    end
  when :var_ref
    var = statement.condition[0]
    if var == s(:kw, "true")
      condition = true
    elsif var == s(:kw, "false")
      condition = false
    end
  end

  # Invert an unless condition
  if statement.type == :unless || statement.type == :unless_mod
    condition = !condition unless condition.nil?
  end
  condition
end