add output parameter

src/logic.js

@@ -103,6 +103,9 @@ const read_previous_events = (path) => {
   return Promise.resolve([]);
 };
 
+const write_events = (path, events) =>
+  fs.writeFile(path, JSON.stringify(events));
+
 const map_event = ({ node: event }) => {
   const ticket_url = pathOr('', ['event_buy_ticket_url'], event);
   const city = get_city_name(event);
@@ -162,4 +165,5 @@ module.exports = {
   parse_args,
   read_previous_events,
   to_unique_events,
+  write_events,
 };

src/scrape.js

@@ -4,6 +4,7 @@ const {
   parse_args,
   read_previous_events,
   to_unique_events,
+  write_events,
 } = require('./logic');
 const { get_page_events } = require('./browse');
 
@@ -28,4 +29,12 @@ const options = parse_args(process.argv.slice(2));
     console.log(JSON.stringify(events));
     process.exit();
   }
+
+  try {
+    await write_events(options.output, events);
+    process.exit();
+  } catch (e) {
+    console.error(e);
+    process.exit(1);
+  }
 })();