4 files changed, 20 insertions, 16 deletions
diff --git a/railties/lib/rails/api/generator.rb b/railties/lib/rails/api/generator.rb
index 3405560b74..126d4d0438 100644
--- a/railties/lib/rails/api/generator.rb
+++ b/railties/lib/rails/api/generator.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "sdoc"
+require "active_support/core_ext/array/extract"
 
 class RDoc::Generator::API < RDoc::Generator::SDoc # :nodoc:
   RDoc::RDoc.add_generator self
@@ -11,7 +12,7 @@ class RDoc::Generator::API < RDoc::Generator::SDoc # :nodoc:
     # since they aren't nested under a definition of the `ActiveStorage` module.
     if visited.empty?
       classes = classes.reject { |klass| active_storage?(klass) }
-      core_exts, classes = classes.partition { |klass| core_extension?(klass) }
+      core_exts = classes.extract! { |klass| core_extension?(klass) }
 
       super.unshift([ "Core extensions", "", "", build_core_ext_subtree(core_exts, visited) ])
     else
diff --git a/railties/lib/rails/backtrace_cleaner.rb b/railties/lib/rails/backtrace_cleaner.rb
index 0e78959966..b1e3c923b7 100644
--- a/railties/lib/rails/backtrace_cleaner.rb
+++ b/railties/lib/rails/backtrace_cleaner.rb
@@ -16,19 +16,7 @@ module Rails
       add_filter { |line| line.sub(@root, EMPTY_STRING) }
       add_filter { |line| line.sub(RENDER_TEMPLATE_PATTERN, EMPTY_STRING) }
       add_filter { |line| line.sub(DOT_SLASH, SLASH) } # for tests
-
-      add_gem_filters
       add_silencer { |line| !APP_DIRS_PATTERN.match?(line) }
     end
-
-    private
-      def add_gem_filters
-        gems_paths = (Gem.path | [Gem.default_dir]).map { |p| Regexp.escape(p) }
-        return if gems_paths.empty?
-
-        gems_regexp = %r{(#{gems_paths.join('|')})/gems/([^/]+)-([\w.]+)/(.*)}
-        gems_result = '\2 (\3) \4'.freeze
-        add_filter { |line| line.sub(gems_regexp, gems_result) }
-      end
   end
 end
diff --git a/railties/lib/rails/commands/dev/dev_command.rb b/railties/lib/rails/commands/dev/dev_command.rb
new file mode 100644
index 0000000000..820dc4db9e
--- /dev/null
+++ b/railties/lib/rails/commands/dev/dev_command.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+require "rails/dev_caching"
+
+module Rails
+  module Command
+    class DevCommand < Base # :nodoc:
+      desc "Toggle development mode caching on/off"
+      def cache
+        Rails::DevCaching.enable_by_file
+      end
+    end
+  end
+end
diff --git a/railties/lib/rails/tasks/dev.rake b/railties/lib/rails/tasks/dev.rake
index 5aea6f7dc5..8d75965294 100644
--- a/railties/lib/rails/tasks/dev.rake
+++ b/railties/lib/rails/tasks/dev.rake
@@ -1,10 +1,11 @@
 # frozen_string_literal: true
 
-require "rails/dev_caching"
+require "rails/command"
+require "active_support/deprecation"
 
 namespace :dev do
-  desc "Toggle development mode caching on/off"
   task :cache do
-    Rails::DevCaching.enable_by_file
+    ActiveSupport::Deprecation.warn("Using `bin/rake dev:cache` is deprecated and will be removed in Rails 6.1. Use `bin/rails dev:cache` instead.\n")
+    Rails::Command.invoke "dev:cache"
   end
 end