From 1dfa04238bb4d8659702770858c14355223dd9ef Mon Sep 17 00:00:00 2001
From: Stefan Magnuson <styrmis@gmail.com>
Date: Wed, 19 Apr 2023 16:37:35 +0100
Subject: [PATCH] Allow tasks to be loaded from nested task directories (#809)

Co-authored-by: Masa (Aileron inc) <masa@aileron.cc>
---
 README.md                                     | 20 +++++++++++++++++++
 app/models/maintenance_tasks/task.rb          |  8 +++++++-
 .../nested/nested_more/nested_more_task.rb    | 15 ++++++++++++++
 .../tasks/maintenance/nested/nested_task.rb   | 13 ++++++++++++
 .../maintenance_tasks/task_data_index_test.rb |  2 ++
 test/models/maintenance_tasks/task_test.rb    |  2 ++
 test/system/maintenance_tasks/tasks_test.rb   |  2 ++
 7 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 test/dummy/app/tasks/maintenance/nested/nested_more/nested_more_task.rb
 create mode 100644 test/dummy/app/tasks/maintenance/nested/nested_task.rb

diff --git a/README.md b/README.md
index 2e350c58..a3661564 100644
--- a/README.md
+++ b/README.md
@@ -696,6 +696,26 @@ MaintenanceTasks.tasks_module = "TaskModule"
 
 If no value is specified, it will default to `Maintenance`.
 
+#### Organizing tasks using namespaces
+
+Tasks may be nested arbitrarily deeply under `app/tasks/maintenance`, for example given a
+task file `app/tasks/maintenance/team_name/service_name/update_posts_task.rb` we
+can define the task as:
+
+```ruby
+module Maintenance
+  module TeamName
+    module ServiceName
+      class UpdatePostsTask < MaintenanceTasks::Task
+        def process(rows)
+          # ...
+        end
+      end
+    end
+  end
+end
+```
+
 #### Customizing the underlying job class
 
 `MaintenanceTasks.job` can be configured to define a Job class for your tasks to
diff --git a/app/models/maintenance_tasks/task.rb b/app/models/maintenance_tasks/task.rb
index 3784dc52..049db9ed 100644
--- a/app/models/maintenance_tasks/task.rb
+++ b/app/models/maintenance_tasks/task.rb
@@ -175,7 +175,13 @@ def load_constants
         namespace = MaintenanceTasks.tasks_module.safe_constantize
         return unless namespace
 
-        namespace.constants.map { |constant| namespace.const_get(constant) }
+        load_const = lambda do |root|
+          root.constants.each do |name|
+            object = root.const_get(name)
+            load_const.call(object) if object.instance_of?(Module)
+          end
+        end
+        load_const.call(namespace)
       end
     end
 
diff --git a/test/dummy/app/tasks/maintenance/nested/nested_more/nested_more_task.rb b/test/dummy/app/tasks/maintenance/nested/nested_more/nested_more_task.rb
new file mode 100644
index 00000000..e56ce6ed
--- /dev/null
+++ b/test/dummy/app/tasks/maintenance/nested/nested_more/nested_more_task.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module Maintenance
+  module Nested
+    module NestedMore
+      class NestedMoreTask < MaintenanceTasks::Task
+        no_collection
+
+        def process
+          # Task only exists to verify correct loading of tasks within subfolders
+        end
+      end
+    end
+  end
+end
diff --git a/test/dummy/app/tasks/maintenance/nested/nested_task.rb b/test/dummy/app/tasks/maintenance/nested/nested_task.rb
new file mode 100644
index 00000000..3b27f8a3
--- /dev/null
+++ b/test/dummy/app/tasks/maintenance/nested/nested_task.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module Maintenance
+  module Nested
+    class NestedTask < MaintenanceTasks::Task
+      no_collection
+
+      def process
+        # Task only exists to verify correct loading of tasks within subfolders
+      end
+    end
+  end
+end
diff --git a/test/models/maintenance_tasks/task_data_index_test.rb b/test/models/maintenance_tasks/task_data_index_test.rb
index c600ac7c..c51357dc 100644
--- a/test/models/maintenance_tasks/task_data_index_test.rb
+++ b/test/models/maintenance_tasks/task_data_index_test.rb
@@ -12,6 +12,8 @@ class TaskDataIndexTest < ActiveSupport::TestCase
         "Maintenance::EnqueueErrorTask",
         "Maintenance::ErrorTask",
         "Maintenance::ImportPostsTask",
+        "Maintenance::Nested::NestedMore::NestedMoreTask",
+        "Maintenance::Nested::NestedTask",
         "Maintenance::NoCollectionTask",
         # duplicate due to fixtures containing two active runs of this task
         "Maintenance::NoCollectionTask",
diff --git a/test/models/maintenance_tasks/task_test.rb b/test/models/maintenance_tasks/task_test.rb
index 27cfac9e..f36b2333 100644
--- a/test/models/maintenance_tasks/task_test.rb
+++ b/test/models/maintenance_tasks/task_test.rb
@@ -12,6 +12,8 @@ class TaskTest < ActiveSupport::TestCase
         "Maintenance::EnqueueErrorTask",
         "Maintenance::ErrorTask",
         "Maintenance::ImportPostsTask",
+        "Maintenance::Nested::NestedMore::NestedMoreTask",
+        "Maintenance::Nested::NestedTask",
         "Maintenance::NoCollectionTask",
         "Maintenance::ParamsTask",
         "Maintenance::TestTask",
diff --git a/test/system/maintenance_tasks/tasks_test.rb b/test/system/maintenance_tasks/tasks_test.rb
index 6a9f7f82..d392b4b2 100644
--- a/test/system/maintenance_tasks/tasks_test.rb
+++ b/test/system/maintenance_tasks/tasks_test.rb
@@ -27,6 +27,8 @@ class TasksTest < ApplicationSystemTestCase
         "Maintenance::CancelledEnqueueTask\nNew",
         "Maintenance::EnqueueErrorTask\nNew",
         "Maintenance::ErrorTask\nNew",
+        "Maintenance::Nested::NestedMore::NestedMoreTask\nNew",
+        "Maintenance::Nested::NestedTask\nNew",
         "Maintenance::ParamsTask\nNew",
         "Maintenance::TestTask\nNew",
         "Maintenance::UpdatePostsInBatchesTask\nNew",