Uncommunicative-Parameter-Name.md

Uncommunicative Parameter Name

Introduction

An Uncommunicative Parameter Name is a parameter name that doesn't communicate its intent well enough. This code smell is a case of Uncommunicative Name.

Current Support in Reek

Uncommunicative Parameter Name checks for:

• single-character names
• any name ending with a number
• camelCaseParameterNames

Configuration

Reek's Uncommunicative Parameter Name detector supports the Basic Smell Options, plus:

Option	Value	Effect
reject	array of strings	The set of names that Reek uses to check for bad names. Defaults to single-letter names, names containing an uppercase letter, names with a number at the end and '_'.
accept	array of strings	The set of names that Reek will accept (and not report) even if they match one of the reject expressions.

An example configuration could look like this:

---
UncommunicativeParameterName:
  accept:
    - x
    - arg1
  reject:
    - foobar

Reek will convert whatever you give it as a string to the corresponding regex, so "foobar" from above will be converted to /foobar/ internally.

Applying a configuration to a source file like this:

def omg(x); x; end # Should not be reported
def omg(arg1); arg1; end # Should not be reported
def omg(foobar); foobar; end # Should be reported

Reek would report:

smelly.rb -- 1 warning:
  [3]:UncommunicativeParameterName: omg has the parameter name 'foobar'

Advanced configuration

Sometimes just strings are not enough for configuration. E.g. consider this code sample:

class Klass
  def my_method(foo, foobar); end
end

and now imagine that you want to reject the name "foo" but not "foobar". This wouldn't be possible with just using strings. For this reason Reek has a special syntax that allows you to use regexes by using a forward slash at the beginning and the end of the string. Everything within the forward slashes will be loaded as a regex.

A possible configuration that allows "foobar" but rejects "foo" could look like this:

---
UncommunicativeParameterName:
  reject:
    - "/^foo$/"

Reek 4

In Reek 4 you could also pass regexes to accept or reject, meaning this was perfectly valid as well:

UncommunicativeParameterName:
  accept:
    - !ruby/regexp /foobar/

Support for this has been scrapped with Reek 5 to make the Reek configuration more yaml standard compliant. You can still pass in regexes, you just have to wrap them into a string. Please see "Advanced configuration" above.