A Cop to detect wasteful initializations

[ashmaroli]

Is your feature request related to a problem? Please describe.

I frequently encounter non-memoized method definitions that involve generation of a constant object that doesn't depend on the state of the Class / Module.

Example

Given that there's a class with following instance methods:

def fallback_data(config)
  {
    :foo => "bar",
    :sit => "amet",
  }.merge(config)
end

def cross_over(type)
  return unless %w[lorem ipsum dolor sit amet alpha].include?(type)

  # proceed doing stuff
end

The Hash generated in :fallback_data and the intermediate array in :cross_over are both going to remain the same in any given instance of the Class. Multiple calls to these methods are going to allocate those objects unnecessarily .

Describe the solution you'd like

Flag such methods and recommend stashing the constant-value objects as "constants", or consider memoizing them as "singleton methods"

[Drenmi]

Hi, @ashmaroli!

The performance cops have recently been moved to their own repository. Please help move your issue over there. Thank you! 🙇

[ashmaroli]

@Drenmi Will you be able to transfer this issue using the GitHub UI?
https://help.github.com/en/articles/transferring-an-issue-to-another-repository

[Drenmi]

Good suggestion @ashmaroli! That's a neat feature which I was not aware of. 🙂

[ashmaroli]

You're welcome, Ted. 🙂