refactor: Move user-sorting code to people.js.

We also remove the blueslip check, since it is
pretty easy to audit the callers here.

frontend_tests/node_tests/people.js

@@ -372,6 +372,31 @@ test_people("basics", () => {
     );
 });
 
+test_people("sort_but_pin_current_user_on_top with me", () => {
+    people.add_active_user(maria);
+    people.add_active_user(steven);
+
+    // We need the actual object from people.js, not the
+    // "me" object we made a copy of.
+    const my_user = people.get_by_user_id(me.user_id);
+    const users = [steven, debbie, maria, my_user];
+
+    people.sort_but_pin_current_user_on_top(users);
+
+    assert.deepEqual(users, [my_user, debbie, maria, steven]);
+});
+
+test_people("sort_but_pin_current_user_on_top without me", () => {
+    people.add_active_user(maria);
+    people.add_active_user(steven);
+
+    const users = [steven, maria];
+
+    people.sort_but_pin_current_user_on_top(users);
+
+    assert.deepEqual(users, [maria, steven]);
+});
+
 test_people("check_active_non_active_users", () => {
     people.add_active_user(bot_botson);
     people.add_active_user(isaac);

frontend_tests/node_tests/stream_edit.js

@@ -127,7 +127,7 @@ test_ui("subscriber_pills", ({override, mock_template}) => {
         () => "stream_subscription_request_result",
     );
 
-    override(stream_edit, "sort_but_pin_current_user_on_top", noop);
+    override(people, "sort_but_pin_current_user_on_top", noop);
 
     const subscriptions_table_selector = "#subscriptions_table";
     const input_field_stub = $.create(".input");

static/js/people.js

@@ -1387,6 +1387,21 @@ export function is_my_user_id(user_id) {
     return user_id === my_user_id;
 }
 
+function compare_by_name(a, b) {
+    return util.strcmp(a.full_name, b.full_name);
+}
+
+export function sort_but_pin_current_user_on_top(users) {
+    const my_user = people_by_user_id_dict.get(my_user_id);
+    if (users.includes(my_user)) {
+        users.splice(users.indexOf(my_user), 1);
+        users.sort(compare_by_name);
+        users.unshift(my_user);
+    } else {
+        users.sort(compare_by_name);
+    }
+}
+
 export function initialize(my_user_id, params) {
     for (const person of params.realm_users) {
         add_active_user(person);

static/js/stream_edit.js

@@ -51,10 +51,6 @@ function setup_subscriptions_stream_hash(sub) {
     browser_history.update(hash);
 }
 
-function compare_by_name(a, b) {
-    return util.strcmp(a.full_name, b.full_name);
-}
-
 export function setup_subscriptions_tab_hash(tab_key_value) {
     if (tab_key_value === "all-streams") {
         browser_history.update("#streams/all");
@@ -341,23 +337,6 @@ export function remove_user_from_stream(user_id, sub, success, failure) {
     });
 }
 
-export function sort_but_pin_current_user_on_top(users) {
-    if (users === undefined) {
-        blueslip.error("Undefined users are passed to function sort_but_pin_current_user_on_top");
-        return;
-    }
-
-    const my_user = people.get_by_email(people.my_current_email());
-    const compare_function = compare_by_name;
-    if (users.includes(my_user)) {
-        users.splice(users.indexOf(my_user), 1);
-        users.sort(compare_function);
-        users.unshift(my_user);
-    } else {
-        users.sort(compare_function);
-    }
-}
-
 export function create_item_from_text(text, current_items) {
     const funcs = [
         stream_pill.create_item_from_stream_name,
@@ -423,7 +402,7 @@ function enable_subscriber_management({sub, parent_container}) {
 
     const user_ids = peer_data.get_subscribers(stream_id);
     const users = get_users_from_subscribers(user_ids);
-    sort_but_pin_current_user_on_top(users);
+    people.sort_but_pin_current_user_on_top(users);
 
     function get_users_for_subscriber_typeahead() {
         const potential_subscribers = peer_data.potential_subscribers(stream_id);

static/js/stream_ui_updates.js

@@ -6,6 +6,7 @@ import {$t} from "./i18n";
 import * as ListWidget from "./list_widget";
 import {page_params} from "./page_params";
 import * as peer_data from "./peer_data";
+import * as people from "./people";
 import * as stream_data from "./stream_data";
 import * as stream_edit from "./stream_edit";
 import * as stream_settings_containers from "./stream_settings_containers";
@@ -193,7 +194,7 @@ export function update_subscribers_list(sub) {
         // Perform re-rendering only when the stream settings form of the corresponding
         // stream is open.
         if (subscribers_list) {
-            stream_edit.sort_but_pin_current_user_on_top(users);
+            people.sort_but_pin_current_user_on_top(users);
             subscribers_list.replace_list_data(users);
         }
         $(".subscriber_list_settings_container").show();