scheduled_messages: Rerender send later options at specific time.

Fixes: #25451.

web/src/popover_menus.js

@@ -835,6 +835,11 @@ export function initialize() {
                 overlays.open_modal("send_later_modal", {
                     autoremove: true,
                     on_show() {
+                        instance._interval = setInterval(
+                            scheduled_messages.update_send_later_options,
+                            scheduled_messages.SCHEDULING_MODAL_UPDATE_INTERVAL_IN_MILLISECONDS,
+                        );
+
                         const $send_later_modal = $("#send_later_modal");
                         $send_later_modal.on("keydown", (e) => {
                             if (e.key === "Enter") {
@@ -877,6 +882,9 @@ export function initialize() {
                             },
                         );
                     },
+                    on_hide() {
+                        clearInterval(instance._interval);
+                    },
                 });
             });
         },

web/src/scheduled_messages.js

@@ -1,6 +1,7 @@
 import $ from "jquery";
 
 import render_success_message_scheduled_banner from "../templates/compose_banner/success_message_scheduled_banner.hbs";
+import render_send_later_modal_options from "../templates/send_later_modal_options.hbs";
 
 import * as channel from "./channel";
 import * as compose from "./compose";
@@ -16,6 +17,8 @@ import * as stream_data from "./stream_data";
 import * as timerender from "./timerender";
 
 export const MINIMUM_SCHEDULED_MESSAGE_DELAY_SECONDS = 5 * 60;
+export const SCHEDULING_MODAL_UPDATE_INTERVAL_IN_MILLISECONDS = 60 * 1000;
+
 export let scheduled_messages_data = [];
 
 function compute_send_times(now = new Date()) {
@@ -322,3 +325,29 @@ export function initialize(scheduled_messages_params) {
         e.stopPropagation();
     });
 }
+
+// This function is exported for unit testing purposes.
+export function should_update_send_later_options(date) {
+    const current_minute = date.getMinutes();
+    const current_hour = date.getHours();
+
+    if (current_hour === 0 && current_minute === 0) {
+        // We need to rerender the available options at midnight,
+        // since Monday could become in range.
+        return true;
+    }
+
+    // Rerender at MINIMUM_SCHEDULED_MESSAGE_DELAY_SECONDS before the
+    // hour, so we don't offer a 4:00PM send time at 3:59 PM.
+    return current_minute === 60 - MINIMUM_SCHEDULED_MESSAGE_DELAY_SECONDS / 60;
+}
+
+export function update_send_later_options() {
+    const now = new Date();
+    if (should_update_send_later_options(now)) {
+        const filtered_send_opts = get_filtered_send_opts(now);
+        $("#send_later_modal .send_later_options").replaceWith(
+            render_send_later_modal_options(filtered_send_opts),
+        );
+    }
+}

web/tests/scheduled_messages.test.js

@@ -104,6 +104,13 @@ function get_expected_send_opts(day, expecteds) {
     return modal_opts;
 }
 
+function get_minutes_to_hour(minutes) {
+    const date = new Date();
+    date.setMinutes(minutes);
+    date.setSeconds(0);
+    return date;
+}
+
 run_test("scheduled_modal_opts", () => {
     // Sunday thru Saturday
     const days = [
@@ -159,3 +166,22 @@ run_test("missing_or_expired_timestamps", () => {
         ),
     );
 });
+
+run_test("should_update_send_later_options", () => {
+    // We should rerender if it is 5 minutes before the hour
+    for (let minute = 0; minute < 60; minute += 1) {
+        const current_time = get_minutes_to_hour(minute);
+        if (minute === 55) {
+            // Should rerender
+            assert.ok(scheduled_messages.should_update_send_later_options(current_time));
+        } else {
+            // Should not rerender
+            assert.ok(!scheduled_messages.should_update_send_later_options(current_time));
+        }
+    }
+
+    // We should rerender at midnight
+    const start_of_the_day = new Date();
+    start_of_the_day.setHours(0, 0);
+    assert.ok(scheduled_messages.should_update_send_later_options(start_of_the_day));
+});