Smell-Suppression.md

Introduction

In some cases, it might be necessary to suppress one or more of Reek's smell warnings for a particular method or class.

Possible reasons for this could be:

• The code is outside of your control and you can't fix it
• Reek is not the police. You might have legit reasons why your source code is good as it is.

How to disable smell detection

There are always the Basic Smell Options you can use in your configuration file.

But in this document we would like to focus on a completely different way - via special comments.

A simple example:

# This method smells of :reek:NestedIterators
def smelly_method foo
  foo.each {|bar| bar.each {|baz| baz.qux}}
end

The method smelly_method will not be reported. The general pattern is to put the string ':reek:', followed by the smell class, in a comment before the method or class.

Extended examples

Multiple smells may be configured for the same method or class:

# :reek:LongParameterList and :reek:NestedIterators
def many_parameters_it_has foo, bar, baz, qux
  foo.each {|bar| bar.each {|baz| baz.qux(qux)}}
end

Or across several lines which is arguably more readable:

# :reek:LongParameterList
# :reek:NestedIterators
def many_parameters_it_has foo, bar, baz, qux
  foo.each {|bar| bar.each {|baz| baz.qux(qux)}}
end

It is also possible to specify options for a particular smell detector in hash-style:

# :reek:LongParameterList { max_params: 4 }
def many_parameters_it_has foo, bar, baz, qux
  # ...
end

Every configuration setting that you can pass via configuration file you can also use via comment.

E.g.:

# :reek:TooManyStatements { max_statements: 6 }
def too_many
  # ...
end

# :reek:NestedIterators { max_allowed_nesting: 2 }
def quax
  foo.each {|bar| bar.each {|baz| baz.qux(qux)}}
end

# :reek:DuplicateMethodCall { max_calls: 3 }
def quax
  foo.to_i + foo.to_i + foo.to_i
end

Keep in mind that there are also smell detectors that operate on a class or module level, e.g.:

# :reek:TooManyInstanceVariables { max_instance_variables: 8 }
class Klass
  # ...
end

To see what smell detector takes what special configuration just check out the dedicated documentation for this smell detector.