drafts: Don't update draft count when successfully sending messages.

Fixes #21757.

Previously the draft count would briefly increase between the action
of sending a message and the success of sending that message.
Now the draft count will only increase if the message fails to send.

frontend_tests/node_tests/compose.js

@@ -147,6 +147,10 @@ test_ui("send_message", ({override, override_rewire}) => {
         return stub_state;
     }
 
+    const $container = $(".top_left_drafts");
+    const $child = $(".unread_count");
+    $container.set_find_results(".unread_count", $child);
+
     override(server_events, "assert_get_events_running", () => {
         stub_state.get_events_running_called += 1;
     });

static/js/compose.js

@@ -11,6 +11,7 @@ import * as compose_fade from "./compose_fade";
 import * as compose_state from "./compose_state";
 import * as compose_ui from "./compose_ui";
 import * as compose_validate from "./compose_validate";
+import * as drafts from "./drafts";
 import * as echo from "./echo";
 import * as flatpickr from "./flatpickr";
 import {$t, $t_html} from "./i18n";
@@ -256,6 +257,10 @@ export function send_message(request = create_message_object()) {
         }
 
         echo.message_send_error(message.id, response);
+
+        // We might not have updated the draft count because we assumed the
+        // message would send. Ensure that the displayed count is correct.
+        drafts.sync_count();
     }
 
     transmit.send_message(request, success, error);

static/js/drafts.js

@@ -56,12 +56,14 @@ export const draft_model = (function () {
         return get()[id] || false;
     };
 
-    function save(drafts) {
+    function save(drafts, update_count = true) {
         ls.set(KEY, drafts);
-        set_count(Object.keys(drafts).length);
+        if (update_count) {
+            set_count(Object.keys(drafts).length);
+        }
     }
 
-    exports.addDraft = function (draft) {
+    exports.addDraft = function (draft, update_count = true) {
         const drafts = get();
 
         // use the base16 of the current time + a random string to reduce
@@ -70,7 +72,7 @@ export const draft_model = (function () {
 
         draft.updatedAt = getTimestamp();
         drafts[id] = draft;
-        save(drafts);
+        save(drafts, update_count);
 
         return id;
     };
@@ -104,6 +106,11 @@ export const draft_model = (function () {
     return exports;
 })();
 
+export function sync_count() {
+    const drafts = draft_model.get();
+    set_count(Object.keys(drafts).length);
+}
+
 export function delete_all_drafts() {
     const drafts = draft_model.get();
     for (const [id] of Object.entries(drafts)) {
@@ -229,9 +236,9 @@ export function update_draft(opts = {}) {
         return draft_id;
     }
 
-    // We have never saved a draft for this message, so add
-    // one.
-    const new_draft_id = draft_model.addDraft(draft);
+    // We have never saved a draft for this message, so add one.
+    const update_count = opts.update_count === undefined ? true : opts.update_count;
+    const new_draft_id = draft_model.addDraft(draft, update_count);
     $("#compose-textarea").data("draft-id", new_draft_id);
     maybe_notify(no_notify);
 

static/js/echo.js

@@ -235,10 +235,10 @@ export function try_deliver_locally(message_request) {
 
     // Save a locally echoed message in drafts, so it cannot be
     // lost. It will be cleared if the message is sent successfully.
-    // We ask the drafts system to not notify the user, since they'd
-    // be quite distracting in the very common case that the message
-    // sends normally.
-    const draft_id = drafts.update_draft({no_notify: true});
+    // We ask the drafts system to not notify the user or update the
+    // draft count, since that would be quite distracting in the very
+    // common case that the message sends normally.
+    const draft_id = drafts.update_draft({no_notify: true, update_count: false});
     message_request.draft_id = draft_id;
 
     // Now that we've committed to delivering the message locally, we