DEV: Allow passing a class to add_automation_scriptable

This commit modify's discourse-automation's add_automation_scriptable
plugin API method to allow passing a class instead of a block.
This helps with readability and separation, since then all of the
scripts do not need to be defined in plugin.rb

There are two requirements for the class:

1. It must have a `self.call` method
2. This `self.call` method must wrap its contents in `proc {}`

This way a block is returned from the class and the rest of
it is evaluated in the same way the block from add_automation_scriptable
usually is.

plugins/automation/lib/discourse_automation/plugin_instance_extension.rb

@@ -2,8 +2,8 @@
 
 module DiscourseAutomation
   module PluginInstanceExtension
-    def add_automation_scriptable(name, &block)
-      reloadable_patch { DiscourseAutomation::Scriptable.add(name, &block) }
+    def add_automation_scriptable(name, scriptable_class = nil, &block)
+      reloadable_patch { DiscourseAutomation::Scriptable.add(name, scriptable_class, &block) }
     end
 
     def add_automation_triggerable(name, &block)

plugins/automation/lib/discourse_automation/scriptable.rb

@@ -285,9 +285,13 @@ module DiscourseAutomation
       end
     end
 
-    def self.add(identifier, &block)
+    def self.add(identifier, scriptable_class = nil, &block)
       @all_scriptables = nil
-      define_method("__scriptable_#{identifier}", &block)
+      if block_given?
+        define_method("__scriptable_#{identifier}", &block)
+      else
+        define_method("__scriptable_#{identifier}", scriptable_class.call)
+      end
     end
 
     def self.remove(identifier)

plugins/automation/spec/integration/core_ext_spec.rb

@@ -26,12 +26,25 @@ describe "Core extensions" do
     end
 
     describe "#add_automation_scriptable" do
+      class MyScriptableClass
+        def self.call
+          proc { puts "Hello world" }
+        end
+      end
+
       it "adds the scriptable" do
         plugin = Plugin::Instance.new nil, "/tmp/test.rb"
         plugin.add_automation_scriptable(:foo) {}
 
         expect(DiscourseAutomation::Scriptable.all).to include(:__scriptable_foo)
       end
+
+      it "adds the scriptable using a class" do
+        plugin = Plugin::Instance.new nil, "/tmp/test.rb"
+        plugin.add_automation_scriptable(:foo, MyScriptableClass)
+
+        expect(DiscourseAutomation::Scriptable.all).to include(:__scriptable_foo)
+      end
     end
   end
 

plugins/chat/lib/chat/send_message_automation_script.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module Chat
+  class SendMessageAutomationScript
+    def self.call
+      proc do
+        field :chat_channel_id, component: :text, required: true
+        field :message, component: :message, required: true, accepts_placeholders: true
+        field :sender, component: :user
+
+        placeholder :channel_name
+
+        triggerables %i[recurring topic_tags_changed post_created_edited]
+
+        script do |context, fields, automation|
+          sender = User.find_by(username: fields.dig("sender", "value")) || Discourse.system_user
+          channel = Chat::Channel.find_by(id: fields.dig("chat_channel_id", "value"))
+          placeholders = { channel_name: channel.title(sender) }.merge(
+            context["placeholders"] || {},
+          )
+
+          creator =
+            ::Chat::CreateMessage.call(
+              chat_channel_id: channel.id,
+              guardian: sender.guardian,
+              message: utils.apply_placeholders(fields.dig("message", "value"), placeholders),
+            )
+
+          if creator.failure?
+            Rails.logger.warn "[discourse-automation] Chat message failed to send:\n#{creator.inspect_steps.inspect}\n#{creator.inspect_steps.error}"
+          end
+        end
+      end
+    end
+  end
+end

plugins/chat/plugin.rb

@@ -457,32 +457,7 @@ after_initialize do
         }
   end
 
-  add_automation_scriptable("send_chat_message") do
-    field :chat_channel_id, component: :text, required: true
-    field :message, component: :message, required: true, accepts_placeholders: true
-    field :sender, component: :user
-
-    placeholder :channel_name
-
-    triggerables %i[recurring topic_tags_changed post_created_edited]
-
-    script do |context, fields, automation|
-      sender = User.find_by(username: fields.dig("sender", "value")) || Discourse.system_user
-      channel = Chat::Channel.find_by(id: fields.dig("chat_channel_id", "value"))
-      placeholders = { channel_name: channel.title(sender) }.merge(context["placeholders"] || {})
-
-      creator =
-        ::Chat::CreateMessage.call(
-          chat_channel_id: channel.id,
-          guardian: sender.guardian,
-          message: utils.apply_placeholders(fields.dig("message", "value"), placeholders),
-        )
-
-      if creator.failure?
-        Rails.logger.warn "[discourse-automation] Chat message failed to send:\n#{creator.inspect_steps.inspect}\n#{creator.inspect_steps.error}"
-      end
-    end
-  end
+  add_automation_scriptable("send_chat_message", Chat::SendMessageAutomationScript)
 
   add_api_key_scope(
     :chat,