refactor: Call peer_data.get_subscriber_count().

We are trying to move away from having the
subscriber count on the sub.

This commit handles the easy one-liners
in the JS code.

frontend_tests/node_tests/stream_pill.js

@@ -5,6 +5,7 @@ const {strict: assert} = require("assert");
 const {zrequire} = require("../zjsunit/namespace");
 const {run_test} = require("../zjsunit/test");
 
+const peer_data = zrequire("peer_data");
 zrequire("stream_data");
 zrequire("stream_pill");
 
@@ -12,24 +13,25 @@ const denmark = {
     stream_id: 1,
     name: "Denmark",
     subscribed: true,
-    subscriber_count: 10,
 };
 const sweden = {
     stream_id: 2,
     name: "Sweden",
     subscribed: false,
-    subscriber_count: 30,
 };
 
+peer_data.set_subscribers(denmark.stream_id, [1, 2, 3]);
+peer_data.set_subscribers(sweden.stream_id, [1, 2, 3, 4, 5]);
+
 const denmark_pill = {
     stream_name: denmark.name,
     stream_id: denmark.stream_id,
-    display_value: "#" + denmark.name + ": " + denmark.subscriber_count + " users",
+    display_value: "#Denmark: 3 users",
 };
 const sweden_pill = {
     stream_name: sweden.name,
     stream_id: sweden.stream_id,
-    display_value: "#" + sweden.name + ": " + sweden.subscriber_count + " users",
+    display_value: "#Sweden: 5 users",
 };
 
 const subs = [denmark, sweden];

static/js/message_view_header.js

@@ -2,15 +2,10 @@
 
 const render_message_view_header = require("../templates/message_view_header.hbs");
 
+const peer_data = require("./peer_data");
 const rendered_markdown = require("./rendered_markdown");
 
-function get_sub_count(current_stream) {
-    const sub_count = current_stream.subscriber_count;
-    return sub_count;
-}
-
-function get_formatted_sub_count(current_stream) {
-    let sub_count = get_sub_count(current_stream);
+function get_formatted_sub_count(sub_count) {
     if (sub_count >= 1000) {
         // parseInt() is used to floor the value of division to an integer
         sub_count = Number.parseInt(sub_count / 1000, 10) + "k";
@@ -42,8 +37,9 @@ function make_message_view_header(filter) {
         // the current user can access.
         const current_stream = filter._sub;
         message_view_header.rendered_narrow_description = current_stream.rendered_description;
-        message_view_header.sub_count = get_sub_count(current_stream);
-        message_view_header.formatted_sub_count = get_formatted_sub_count(current_stream);
+        const sub_count = peer_data.get_subscriber_count(current_stream.stream_id);
+        message_view_header.sub_count = sub_count;
+        message_view_header.formatted_sub_count = get_formatted_sub_count(sub_count);
         // the "title" is passed as a variable and doesn't get translated (nor should it)
         message_view_header.sub_count_tooltip_text = i18n.t(
             "__count__ users are subscribed to #__title__",

static/js/stream_pill.js

@@ -3,7 +3,8 @@
 const peer_data = require("./peer_data");
 
 function display_pill(sub) {
-    return "#" + sub.name + ": " + sub.subscriber_count + " users";
+    const sub_count = peer_data.get_subscriber_count(sub.stream_id);
+    return "#" + sub.name + ": " + sub_count + " users";
 }
 
 exports.create_item_from_stream_name = function (stream_name, current_items) {

static/js/stream_ui_updates.js

@@ -174,16 +174,22 @@ exports.update_subscribers_count = function (sub, just_subscribed) {
         // If the streams overlay isn't open, we don't need to rerender anything.
         return;
     }
+
     const stream_row = subs.row_for_stream_id(sub.stream_id);
+    const sub_count = peer_data.get_subscriber_count(sub.stream_id);
+
     if (
         !sub.can_access_subscribers ||
         (just_subscribed && sub.invite_only) ||
         page_params.is_guest
     ) {
-        const rendered_sub_count = render_subscription_count(sub);
+        const rendered_sub_count = render_subscription_count({
+            can_access_subscribers: sub.can_access_subscribers,
+            subscriber_count: sub_count,
+        });
         stream_row.find(".subscriber-count").expectOne().html(rendered_sub_count);
     } else {
-        stream_row.find(".subscriber-count-text").expectOne().text(sub.subscriber_count);
+        stream_row.find(".subscriber-count-text").expectOne().text(sub_count);
     }
 };