Record all players as leaving on server exit

In the case of shutdown the Factorio server will not notify the
currently online players as leaving the game.  Notify the master server
that all remaining online players quit the game in this case.

packages/lib/plugin.js

@@ -210,7 +210,8 @@ class BaseInstancePlugin {
 	 * @param {string} event.name - Name of the player that joined/left.
 	 * @param {string=} event.reason -
 	 *     Only present for type "leave". Reason for player leaving the
-	 *     game, one of the possible reasons in defines.disconnect_reason.
+	 *     game, one of the possible reasons in defines.disconnect_reason
+	 *     or "server_quit" if the server exits while the player is online.
 	 */
 	async onPlayerEvent(event) { }
 
@@ -505,7 +506,8 @@ class BaseMasterPlugin {
 	 * @param {string} event.name - Name of the player that joined/left.
 	 * @param {string=} event.reason -
 	 *     Only present for type "leave". Reason for player leaving the
-	 *     game, one of the possible reasons in defines.disconnect_reason.
+	 *     game, one of the possible reasons in defines.disconnect_reason
+	 *     or "server_quit" if the server exits while the player is online.
 	 */
 	async onPlayerEvent(instance, event) { }
 

packages/slave/src/Instance.js

@@ -483,6 +483,9 @@ class Instance extends libLink.Link {
 			pluginInstance.onExit();
 		}
 
+		for (let player of left) {
+			this._recordPlayerLeave(player, "server_quit");
+		}
 		this._saveStats().catch(err => this.logger.error(`Error saving stats:\n${err.stack}`));
 	}