Merge pull request #507 from walf443/improve_rspec_config_pattern

Improve performance when user does not override default RSpec Pattern config

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Master (Unreleased)
 
+* Improve performance when user does not override default RSpec Pattern config. ([@walf443][])
+
 ## 1.20.1 (2017-11-15)
 
 * Add "without" to list of default allowed prefixes for `RSpec/ContextWording`. ([@bquorning][])

lib/rubocop/cop/rspec/cop.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module RuboCop
  module Cop # rubocop:disable Style/Documentation
  WorkaroundCop = Cop.dup
@@ -42,6 +44,11 @@ class Cop < WorkaroundCop
  DEFAULT_CONFIGURATION =
  RuboCop::RSpec::CONFIG.fetch('AllCops').fetch('RSpec')
 
+ DEFAULT_PATTERN_RE = Regexp.union(
+ DEFAULT_CONFIGURATION.fetch('Patterns')
+ .map(&Regexp.public_method(:new))
+ )
+
  # Invoke the original inherited hook so our cops are recognized
  def self.inherited(subclass)
  RuboCop::Cop::Cop.inherited(subclass)
@@ -58,12 +65,25 @@ def relevant_rubocop_rspec_file?(file)
  end
 
  def rspec_pattern
- Regexp.union(rspec_pattern_config.map(&Regexp.public_method(:new)))
+ if rspec_pattern_config?
+ Regexp.union(rspec_pattern_config.map(&Regexp.public_method(:new)))
+ else
+ DEFAULT_PATTERN_RE
+ end
  end
 
- def rspec_pattern_config
+ def all_cops_config
  config
  .for_all_cops
+ end
+
+ def rspec_pattern_config?
+ return unless all_cops_config.key?('RSpec')
+ all_cops_config.fetch('RSpec').key?('Patterns')
+ end
+
+ def rspec_pattern_config
+ all_cops_config
  .fetch('RSpec', DEFAULT_CONFIGURATION)
  .fetch('Patterns')
  end