From 179a5b8770e99dd468ae5e7a1eb49fcea3b411b9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Puyet?= <sebastien@puyet.fr>
Date: Mon, 9 Sep 2019 13:50:01 +0200
Subject: [PATCH] Fix folders update watcher with no folders to watch (#36163)

* boot when there is folders to watch

* raise argument error when paths are empty

* add space between curly braces

* Revert "add space between curly braces"

This reverts commit 90cff20c87c088df4e95aa2b6c4331a469da7ce7.

* Revert "raise argument error when paths are empty"

This reverts commit 349adff0f5e667c3e882909ffb950f22b13cec1c.

* stop lazy loading listem gem

* back with any?

* require listen gem at top of the file

* improve

* remove scope resolution operator
---
 .../active_support/evented_file_update_checker.rb | 15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/activesupport/lib/active_support/evented_file_update_checker.rb b/activesupport/lib/active_support/evented_file_update_checker.rb
index 6075e0a3d3..d0b8153030 100644
--- a/activesupport/lib/active_support/evented_file_update_checker.rb
+++ b/activesupport/lib/active_support/evented_file_update_checker.rb
@@ -3,6 +3,7 @@
 require "set"
 require "pathname"
 require "concurrent/atomic/atomic_boolean"
+require "listen"
 
 module ActiveSupport
   # Allows you to "listen" to changes in a file system.
@@ -55,16 +56,6 @@ module ActiveSupport
       dtw = directories_to_watch
       @dtw, @missing = dtw.partition(&:exist?)
 
-      if @dtw.any?
-        # Loading listen triggers warnings. These are originated by a legit
-        # usage of attr_* macros for private attributes, but adds a lot of noise
-        # to our test suite. Thus, we lazy load it and disable warnings locally.
-        silence_warnings do
-          require "listen"
-        rescue LoadError => e
-          raise LoadError, "Could not load the 'listen' gem. Add `gem 'listen'` to the development group of your Gemfile", e.backtrace
-        end
-      end
       boot!
     end
 
@@ -109,9 +100,7 @@ module ActiveSupport
       def boot!
         normalize_dirs!
 
-        unless @dtw.empty?
-          Listen.to(*@dtw, &method(:changed)).start
-        end
+        Listen.to(*@dtw, &method(:changed)).start if @dtw.any?
       end
 
       def shutdown!