From c2e5d68252b098821e96d442b4948360d1e00d38 Mon Sep 17 00:00:00 2001
From: wintan1418 <wintan1418@gmail.com>
Date: Thu, 30 Jul 2026 11:51:37 +0100
Subject: [PATCH] Reschedule dynamic recurring tasks when they are updated

The scheduler's polling cycle only handled created and deleted dynamic
tasks. A task whose schedule, class, arguments or any other attribute
changed fell through both checks, so the scheduler kept firing on the
old definition until the process was restarted.

Keep the previously loaded snapshot of dynamic tasks and compare each
reloaded task's updated_at against it, cancelling and rescheduling any
task that changed.

Fixes rails/solid_queue#738
---
 .../scheduler/recurring_schedule.rb           | 12 +++++++++++
 test/unit/scheduler_test.rb                   | 20 +++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/lib/solid_queue/scheduler/recurring_schedule.rb b/lib/solid_queue/scheduler/recurring_schedule.rb
index 526a8edc..36cdc231 100644
--- a/lib/solid_queue/scheduler/recurring_schedule.rb
+++ b/lib/solid_queue/scheduler/recurring_schedule.rb
@@ -48,8 +48,10 @@ def task_keys
 
     def reschedule_dynamic_tasks
       wrap_in_app_executor do
+        previous_tasks = dynamic_tasks.index_by(&:key)
         reload_dynamic_tasks
         schedule_created_dynamic_tasks
+        reschedule_updated_dynamic_tasks(previous_tasks)
         unschedule_deleted_dynamic_tasks
       end
     end
@@ -75,6 +77,16 @@ def schedule_created_dynamic_tasks
         end
       end
 
+      def reschedule_updated_dynamic_tasks(previous_tasks)
+        dynamic_tasks.each do |task|
+          previous_task = previous_tasks[task.key]
+          next if previous_task.nil? || previous_task.updated_at == task.updated_at
+
+          scheduled_tasks[task.key]&.cancel
+          schedule_task(task)
+        end
+      end
+
       def unschedule_deleted_dynamic_tasks
         (scheduled_tasks.keys - RecurringTask.pluck(:key)).each do |key|
           scheduled_tasks[key].cancel
diff --git a/test/unit/scheduler_test.rb b/test/unit/scheduler_test.rb
index e914a23c..241501e9 100644
--- a/test/unit/scheduler_test.rb
+++ b/test/unit/scheduler_test.rb
@@ -131,6 +131,26 @@ class SchedulerTest < ActiveSupport::TestCase
     scheduler&.stop
   end
 
+  test "picks up updates to dynamic tasks post-start" do
+    task = SolidQueue::RecurringTask.create!(
+      key: "updatable_task", static: false, class_name: "AddToBufferJob", schedule: "every hour", arguments: [ 42 ]
+    )
+
+    scheduler = SolidQueue::Scheduler.new(recurring_tasks: {}, dynamic_tasks_enabled: true, polling_interval: 0.1).tap(&:start)
+
+    wait_for_registered_processes(1, timeout: 1.second)
+
+    task.update!(schedule: "every second")
+
+    wait_while_with_timeout(3.seconds) { SolidQueue::Job.count < 1 }
+
+    skip_active_record_query_cache do
+      assert SolidQueue::Job.count >= 1, "Expected the updated schedule to enqueue jobs without a scheduler restart"
+    end
+  ensure
+    scheduler&.stop
+  end
+
   test "updates metadata after removing dynamic task post-start" do
     old_dynamic_task = SolidQueue::RecurringTask.create!(
       key: "old_dynamic_task",