Class: RuboCop::Cop::Modularization::ClassMethodsAsPublicApis

Inherits:
Base
  • Object
show all
Extended by:
T::Sig
Defined in:
lib/rubocop/cop/modularization/class_methods_as_public_apis.rb

Overview

This cop states that public API should live on class methods, which are more easily statically analyzable, searchable, and typically hold less state.

Examples:


# bad
# packs/foo/app/public/foo.rb
module Foo
  def blah
  end
end

# good
# packs/foo/app/public/foo.rb
module Foo
  def self.blah
  end
end

AcceptableParentClasses: [T::Enum, T::Struct, Struct, OpenStruct] (default)

You can define `AcceptableParentClasses` which are a list of classes that, if inherited from, non-class methods are permitted.
This is useful when value objects are a part of your public API.

# good
# packs/foo/app/public/foo.rb
class Foo < T::Enum
  const :blah
end

Instance Method Summary collapse

Instance Method Details

#on_def(node) ⇒ Object 



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# File 'lib/rubocop/cop/modularization/class_methods_as_public_apis.rb', line 45

def on_def(node)
  # This cop only applies for ruby files in `app/public`
  return if !processed_source.file_path.include?('app/public')

  # Looked at https://www.rubydoc.info/gems/rubocop/RuboCop/Cop/Lint/MissingSuper source code as inspiration for htis part.
  class_node = node.each_ancestor(:class).first
  module_node = node.each_ancestor(:module).first
  parent_class = class_node&.parent_class || module_node&.parent

  acceptable_parent_classes = cop_config['AcceptableParentClasses'] || []

  # Used this PR as inspiration to check if we're within a `class << self` block
  uses_implicit_static_methods = node.each_ancestor(:sclass).first&.identifier&.source == 'self'
  class_is_allowed_to_have_instance_methods = acceptable_parent_classes.include?(parent_class&.const_name)
  return if uses_implicit_static_methods || class_is_allowed_to_have_instance_methods

  add_offense(
    node.source_range,
    message: format(
      'Top-level files in the public/ folder may only define class methods.'
    )
  )
end

#support_autocorrect? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/modularization/class_methods_as_public_apis.rb', line 40

def support_autocorrect?
  false
end