From bc0c83691a74ca85768bd5ab488c3184319ca51a Mon Sep 17 00:00:00 2001
From: Maciej Mensfeld <maciej@mensfeld.pl>
Date: Sun, 20 Nov 2022 21:00:44 +0100
Subject: [PATCH] Make the state hash fully thread safe

Fixes issue described here: https://github.com/ruby-concurrency/concurrent-ruby/issues/970
---
 lib/finite_machine/hooks.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/finite_machine/hooks.rb b/lib/finite_machine/hooks.rb
index 5007671..26732e5 100644
--- a/lib/finite_machine/hooks.rb
+++ b/lib/finite_machine/hooks.rb
@@ -18,7 +18,7 @@ class Hooks
     def initialize
       @hooks_map = Concurrent::Map.new do |events_hash, hook_event|
         events_hash[hook_event] = Concurrent::Map.new do |state_hash, name|
-          state_hash[name] = []
+          state_hash.compute_if_absent(name) { [] }
         end
       end
     end