Allow disabling pending migration prompt (#570)

Closes #540

Allow disabling the pending migration prompt through an addon setting. To disable, users can add this to their configuration:

```json
"rubyLsp.addonSettings": {
   "Ruby LSP Rails": {
     "enablePendingMigrationsPrompt": false
   }
 }
```

lib/ruby_lsp/ruby_lsp_rails/addon.rb

@@ -32,6 +32,12 @@ def initialize
         @rails_runner_client = T.let(NullClient.new, RunnerClient)
         @global_state = T.let(nil, T.nilable(GlobalState))
         @outgoing_queue = T.let(nil, T.nilable(Thread::Queue))
+        @settings = T.let(
+          {
+            enablePendingMigrationsPrompt: true,
+          },
+          T::Hash[Symbol, T.untyped],
+        )
         @addon_mutex = T.let(Mutex.new, Mutex)
         @client_mutex = T.let(Mutex.new, Mutex)
         @client_mutex.lock
@@ -58,6 +64,9 @@ def activate(global_state, outgoing_queue)
         @outgoing_queue = outgoing_queue
         @outgoing_queue << Notification.window_log_message("Activating Ruby LSP Rails add-on v#{VERSION}")
 
+        addon_settings = @global_state.settings_for_addon(name)
+        @settings.merge!(addon_settings) if addon_settings
+
         register_additional_file_watchers(global_state: global_state, outgoing_queue: outgoing_queue)
 
         # Start booting the real client in a background thread. Until this completes, the client will be a NullClient
@@ -258,6 +267,7 @@ def fixture_file_watcher
       def offer_to_run_pending_migrations
         return unless @outgoing_queue
         return unless @global_state&.client_capabilities&.window_show_message_supports_extra_properties
+        return unless @settings[:enablePendingMigrationsPrompt]
 
         migration_message = @rails_runner_client.pending_migrations_message
         return unless migration_message

test/ruby_lsp_rails/addon_test.rb

@@ -92,6 +92,35 @@ class AddonTest < ActiveSupport::TestCase
       ensure
         T.must(outgoing_queue).close
       end
+
+      test "migration dialog respects enabled setting" do
+        outgoing_queue = Thread::Queue.new
+        global_state = GlobalState.new
+        global_state.apply_options({
+          capabilities: { window: { showMessage: { messageActionItem: { additionalPropertiesSupport: true } } } },
+          initializationOptions: { addonSettings: { "Ruby LSP Rails": { enablePendingMigrationsPrompt: false } } },
+        })
+
+        refute(T.must(global_state.settings_for_addon("Ruby LSP Rails"))[:enablePendingMigrationsPrompt])
+
+        addon = Addon.new
+        addon.activate(global_state, outgoing_queue)
+
+        # Wait until activation is done
+        Thread.new do
+          addon.rails_runner_client
+        end.join
+
+        RunnerClient.any_instance.expects(:pending_migrations_message).never
+        addon.workspace_did_change_watched_files([
+          {
+            uri: "file://#{dummy_root}/db/migrate/20210901000000_create_foos.rb",
+            type: RubyLsp::Constant::FileChangeType::CREATED,
+          },
+        ])
+      ensure
+        T.must(outgoing_queue).close
+      end
     end
   end
 end