How to test `alias_method`?

Question

I have a class as follows:

class User
  alias_method :nickname, :username

  def username
    self.name.split(' ').first.downcase
  end
end

I would like to test that the method :nickname is an alias for :username.

Both the following don't work:

user = User.new
User.instance_method(:nick_name) == User.instance_method(:username)
user.method(:nick_name) == user.method(:username)

A similar discussion happened at How to test method alias ruby , but the answers stated there don't work.

Works for me, the `alias_method` needs to be after the username definition though. — Ho Man, Jul 15 '17 at 13:45

score 1 · Accepted Answer · answered Jul 15 '17 at 13:45

1

The answer you shared the link for discusses about class methods, here you have instance methods. and yes, as correctly pointed out by @HoMan in the comments, following should work..

class User
  def username
    self.name.split(' ').first.downcase
  end

  alias nickname, username
end

In you testcases,

user = User.last
user.nick_name == user.username

answered Jul 15 '17 at 13:45

Md. Farhan Memon

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This only works if the method being aliased does not have side effects. – Arie Xiao Jul 15 '17 at 15:41

How to test `alias_method`?

1 Answers1