Change Rails/RootPathnameMethods to detect offenses on Dir.[]

changelog/change_rails_root_pathname_methods_to_detect_offenses_on_dir_index.md

@@ -0,0 +1 @@
+* [#1003](https://github.com/rubocop/rubocop-rails/pull/1003): Change `Rails/RootPathnameMethods` to detect offenses on `Dir.[]`. ([@r7kamura][])

lib/rubocop/cop/rails/root_pathname_methods.rb

@@ -38,7 +38,7 @@ class RootPathnameMethods < Base # rubocop:disable Metrics/ClassLength
 
  MSG = '`%<rails_root>s` is a `Pathname` so you can just append `#%<method>s`.'
 
- DIR_GLOB_METHODS = %i[glob].to_set.freeze
+ DIR_GLOB_METHODS = %i[[] glob].to_set.freeze
 
  DIR_NON_GLOB_METHODS = %i[
  children
@@ -171,7 +171,7 @@ class RootPathnameMethods < Base # rubocop:disable Metrics/ClassLength
 
  def_node_matcher :dir_glob?, <<~PATTERN
  (send
- (const {cbase nil?} :Dir) :glob ...)
+ (const {cbase nil?} :Dir) DIR_GLOB_METHODS ...)
  PATTERN
 
  def_node_matcher :rails_root_pathname?, <<~PATTERN
@@ -190,7 +190,7 @@ def on_send(node)
  evidence(node) do |method, path, args, rails_root|
  add_offense(node, message: format(MSG, method: method, rails_root: rails_root.source)) do |corrector|
  replacement = if dir_glob?(node)
- build_path_glob_replacement(path, method)
+ build_path_glob_replacement(path)
  else
  build_path_replacement(path, method, args)
  end
@@ -217,12 +217,12 @@ def pathname_method(node)
  end
  end
 
- def build_path_glob_replacement(path, method)
+ def build_path_glob_replacement(path)
  receiver = range_between(path.source_range.begin_pos, path.children.first.loc.selector.end_pos).source
 
  argument = path.arguments.one? ? path.first_argument.source : join_arguments(path.arguments)
 
- "#{receiver}.#{method}(#{argument})"
+ "#{receiver}.glob(#{argument})"
  end
 
  def build_path_replacement(path, method, args)

spec/rubocop/cop/rails/root_pathname_methods_spec.rb

@@ -2,15 +2,13 @@
 
 RSpec.describe RuboCop::Cop::Rails::RootPathnameMethods, :config do
  {
- Dir: described_class::DIR_METHODS,
+ Dir: described_class::DIR_NON_GLOB_METHODS,
  File: described_class::FILE_METHODS,
  FileTest: described_class::FILE_TEST_METHODS,
  FileUtils: described_class::FILE_UTILS_METHODS,
  IO: described_class::FILE_METHODS
  }.each do |receiver, methods|
  methods.each do |method|
- next if method == :glob
-
  it "registers an offense when using `#{receiver}.#{method}(Rails.public_path)` (if arity exists)" do
  expect_offense(<<~RUBY, receiver: receiver, method: method)
  %{receiver}.%{method}(Rails.public_path)
@@ -143,6 +141,19 @@
  end
  end
 
+ context 'when using Dir.[] on Ruby 2.5 or higher', :ruby25 do
+ it 'registers offense when using `Dir[Rails.root.join(...)]`' do
+ expect_offense(<<~RUBY)
+ Dir[Rails.root.join('spec/support/**/*.rb')]
+ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `Rails.root` is a `Pathname` so you can just append `#[]`.
+ RUBY
+
+ expect_correction(<<~RUBY)
+ Rails.root.glob('spec/support/**/*.rb')
+ RUBY
+ end
+ end
+
  # This is handled by `Rails/RootJoinChain`
  it 'does not register an offense when using `File.read(Rails.root.join(...).join(...))`' do
  expect_no_offenses(<<~RUBY)