Utility Function

A Utility Function is any instance method that has no dependency on the state of the instance.

Current Support in Reek

Currently Utility Function will warn about any method that:

• is non-empty
• does not override an inherited method
• calls at least one method on another object
• doesn’t use any of self’s instance variables
• doesn’t use any of self’s methods

Configuration

Reek’s Utility Function detector supports the Basic Smell Options, plus:

Earlier versions of the UtilityFunction detector were too strict for some cases. In particular, a simple helper method of the form:

def lookup(key)
  TOKENS[key]
end

would always be reported as a UtilityFunction in early versions of Reek. The option max_helper_calls now (since v1.1.3.16) by default requires a method to make at least two calls out of the current object in order to be considered a UtilityFunction.