wrstudios/frodata

Classes and modules are the units of reuse and release. It is therefore considered good practice to annotate every class and module with a brief comment outlining its responsibilities.

Example

Given

class Dummy
  # Do things...
end

Reek would emit the following warning:

test.rb -- 1 warning:
  [1]:Dummy has no descriptive comment (IrresponsibleModule)

Fixing this is simple - just an explaining comment:

# The Dummy class is responsible for ...
class Dummy
  # Do things...
end

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

This cop checks for private or protected access modifiers which are applied to a singleton method. These access modifiers do not make singleton methods private/protected. private_class_method can be used for that.

Example:

# bad

class C
  private

  def self.method
    puts 'hi'
  end
end

Example:

# good

class C
  def self.method
    puts 'hi'
  end

  private_class_method :method
end

Example:

# good

class C
  class << self
    private

    def method
      puts 'hi'
    end
  end
end

This cop checks for redundant access modifiers, including those with no code, those which are repeated, and leading public modifiers in a class or module body. Conditionally-defined methods are considered as always being defined, and thus access modifiers guarding such methods are not redundant.

Example:

class Foo
  public # this is redundant (default access is public)

  def method
  end

  private # this is not redundant (a method is defined)
  def method2
  end

  private # this is redundant (no following methods are defined)
end

Example:

class Foo
  # The following is not redundant (conditionally defined methods are
  # considered as always defining a method)
  private

  if condition?
    def method
    end
  end

  protected # this is not redundant (method is defined)

  define_method(:method2) do
  end

  protected # this is redundant (repeated from previous modifier)

  [1,2,3].each do |i|
    define_method("foo#{i}") do
    end
  end

  # The following is redundant (methods defined on the class'
  # singleton class are not affected by the public modifier)
  public

  def self.method3
  end
end

Example:

# Lint/UselessAccessModifier:
#   ContextCreatingMethods:
#     - concerning
require 'active_support/concern'
class Foo
  concerning :Bar do
    def some_public_method
    end

    private

    def some_private_method
    end
  end

  # this is not redundant because `concerning` created its own context
  private

  def some_other_private_method
  end
end

Example:

# Lint/UselessAccessModifier:
#   MethodCreatingMethods:
#     - delegate
require 'active_support/core_ext/module/delegation'
class Foo
  # this is not redundant because `delegate` creates methods
  private

  delegate :method_a, to: :method_b
end

This cop checks for missing top-level documentation of classes and modules. Classes with no body are exempt from the check and so are namespace modules - modules that have nothing in their bodies except classes, other modules, or constant definitions.

The documentation requirement is annulled if the class or module has a "#:nodoc:" comment next to it. Likewise, "#:nodoc: all" does the same for all its children.

Example:

# bad
class Person
  # ...
end

# good
# Description/Explanation of Person class
class Person
  # ...
end