Follow up to #2552.

Author: myronmarston

Changelog.md

@@ -19,6 +19,8 @@ Enhancements:
   Specification](https://specifications.freedesktop.org/basedir-spec/latest/)
   for the global options file. `~/.rspec` is still supported when no
   options file is found in `$XDG_CONFIG_HOME/rspec/options` (Magnus Bergmark, #2538)
+* Extract `RSpec.world.prepare_example_filtering` that sets up the
+  example filtering for custom RSpec runners. (Oleg Pudeyev, #2552)
 
 Bug Fixes:
 

lib/rspec/core/world.rb

@@ -26,10 +26,11 @@ def initialize(configuration=RSpec.configuration)
 
       # @api public
       #
-      # Creates the list of filtered examples given current configuration.
+      # Prepares filters so that they apply to example groups when they run.
       #
       # This is a separate method so that filters can be modified/replaced and
-      # examples refiltered during a process's lifetime.
+      # examples refiltered during a process's lifetime, which can be useful for
+      # a custom runner.
       def prepare_example_filtering
         @filtered_examples = Hash.new do |hash, group|
           hash[group] = filter_manager.prune(group.examples)