submessage: Send only relevant 'event' array data.

We sent entire 'events' array to 'widgetize.activate' and then
removed its first element(using .shift()); instead we should
send only relevant data ie. the entire array after the first element.

This also helps us avoid an extra check in node tests.

web/src/submessage.js

@@ -50,9 +50,10 @@ export function do_process_submessages(in_opts) {
     if (!events) {
         return;
     }
+    const [widget_event, ...inbound_events] = events;
 
-    if (events[0].sender_id !== message.sender_id) {
-        blueslip.warn(`User ${events[0].sender_id} tried to hijack message ${message.id}`);
+    if (widget_event.sender_id !== message.sender_id) {
+        blueslip.warn(`User ${widget_event.sender_id} tried to hijack message ${message.id}`);
         return;
     }
 
@@ -60,7 +61,7 @@ export function do_process_submessages(in_opts) {
 
     // Right now, our only use of submessages is widgets.
 
-    const data = events[0].data;
+    const data = widget_event.data;
 
     if (data === undefined) {
         return;
@@ -77,7 +78,7 @@ export function do_process_submessages(in_opts) {
     widgetize.activate({
         widget_type,
         extra_data: data.extra_data,
-        events,
+        events: inbound_events,
         $row,
         message,
         post_to_server,

web/src/widgetize.ts

@@ -58,8 +58,6 @@ export function activate(in_opts: WidgetOptions): void {
     const message = in_opts.message;
     const post_to_server = in_opts.post_to_server;
 
-    events.shift();
-
     if (!widgets.has(widget_type)) {
         if (widget_type === "tictactoe") {
             return; // don't warn for deleted legacy widget

web/tests/widgetize.test.js

@@ -46,8 +46,6 @@ const fake_poll_widget = {
         assert.ok($widget_elem.hasClass("widget-content"));
         $widget_elem.handle_events = (e) => {
             is_event_handled = true;
-            assert.notDeepStrictEqual(e, events);
-            events.shift();
             assert.deepStrictEqual(e, events);
         };
         data.callback("test_data");