stream: Allow non-admins to create channel without subscribing to it.

Fixes #33125.
We now add a creator pill on the channel create screen. For the rule to
not allow non admins to create a channel without subscribing to it, the
rule was most probably introduced to prevent creating a private channel
that you can't access and creating a public channel and then not being
able to find it. Those concerns aren't valid anymore with the new group
permissions system and UX changes respectively.
See
https://chat.zulip.org/#narrow/channel/101-design/topic/Rework.20UX.20for.20adding.20everyone.20to.20a.20channel.20or.20group.20.2333127/near/2064926
for more details.

web/src/stream_create.ts

@@ -12,7 +12,6 @@ import {$t, $t_html} from "./i18n.ts";
 import * as keydown_util from "./keydown_util.ts";
 import * as loading from "./loading.ts";
 import * as onboarding_steps from "./onboarding_steps.ts";
-import * as people from "./people.ts";
 import * as settings_components from "./settings_components.ts";
 import * as settings_data from "./settings_data.ts";
 import {current_user, realm} from "./state_data.ts";
@@ -84,16 +83,6 @@ class StreamSubscriptionError {
         $("#stream_subscription_error").show();
     }
 
-    cant_create_stream_without_subscribing(): void {
-        $("#stream_subscription_error").text(
-            $t({
-                defaultMessage:
-                    "You must be an organization administrator to create a channel without subscribing.",
-            }),
-        );
-        $("#stream_subscription_error").show();
-    }
-
     clear_errors(): void {
         $("#stream_subscription_error").hide();
     }
@@ -596,11 +585,6 @@ export function set_up_handlers(): void {
             return;
         }
 
-        if (!principals.includes(people.my_current_user_id()) && !current_user.is_admin) {
-            stream_subscription_error.cant_create_stream_without_subscribing();
-            return;
-        }
-
         if (principals.length >= 50) {
             const html_body = render_subscription_invites_warning_modal({
                 channel_name: stream_name,

web/src/stream_create_subscribers.ts

@@ -11,6 +11,7 @@ import {current_user} from "./state_data.ts";
 import * as stream_create_subscribers_data from "./stream_create_subscribers_data.ts";
 import type {CombinedPillContainer} from "./typeahead_helper.ts";
 import * as user_groups from "./user_groups.ts";
+import * as user_pill from "./user_pill.ts";
 import * as user_sort from "./user_sort.ts";
 
 export let pill_widget: CombinedPillContainer;
@@ -113,7 +114,6 @@ export function build_widgets(): void {
                 user_id: user.user_id,
                 full_name: user.full_name,
                 is_current_user: user.user_id === current_user_id,
-                disabled: stream_create_subscribers_data.must_be_subscribed(user.user_id),
                 img_src: people.small_avatar_url_for_person(user),
                 soft_removed: stream_create_subscribers_data.user_id_in_soft_remove_list(
                     user.user_id,
@@ -137,6 +137,8 @@ export function build_widgets(): void {
             return $(`#${CSS.escape("user_checkbox_" + user.user_id)}`);
         },
     });
+    const current_person = people.get_by_user_id(current_user.user_id);
+    user_pill.append_user(current_person, pill_widget);
 }
 
 export function add_user_id_to_new_stream(user_id: number): void {

web/src/stream_create_subscribers_data.ts

@@ -35,11 +35,6 @@ export function get_potential_subscribers(): User[] {
     const potential_subscribers = people.get_realm_users();
     return potential_subscribers.filter((user) => !user_id_set.has(user.user_id));
 }
-
-export function must_be_subscribed(user_id: number): boolean {
-    return !current_user.is_admin && user_id === current_user.user_id;
-}
-
 export function add_user_ids(user_ids: number[]): void {
     for (const user_id of user_ids) {
         if (!user_id_set.has(user_id)) {
@@ -62,12 +57,6 @@ export function remove_user_ids(user_ids: number[]): void {
 }
 
 export function sync_user_ids(user_ids: number[]): void {
-    // Current user does not have their pill in their input
-    // box, so we need to make sure that we don't delete
-    // it unnecessarily while syncing.
-    if (user_id_set.has(current_user.user_id)) {
-        user_ids.push(current_user.user_id);
-    }
     user_id_set = new Set(user_ids);
 }
 

web/templates/stream_settings/new_stream_user.hbs

@@ -11,7 +11,7 @@
         {{#if soft_removed}}
             <button data-user-id="{{user_id}}" class="undo_soft_removed_potential_subscriber button small rounded white">{{t 'Add' }}</button>
         {{else}}
-            <button {{#if disabled}} disabled="disabled"{{/if}} data-user-id="{{user_id}}" class="remove_potential_subscriber button small rounded white">{{t 'Remove' }}</button>
+            <button data-user-id="{{user_id}}" class="remove_potential_subscriber button small rounded white">{{t 'Remove' }}</button>
         {{/if}}
     </td>
 </tr>

web/tests/stream_create_subscribers_data.test.cjs

@@ -68,33 +68,11 @@ test("basics", () => {
         test_user101,
         test_user103,
     ]);
-
-    assert.ok(stream_create_subscribers_data.must_be_subscribed(me.user_id));
-    assert.ok(!stream_create_subscribers_data.must_be_subscribed(test_user101.user_id));
-});
-
-test("must_be_subscribed", ({override}) => {
-    override(current_user, "is_admin", false);
-    assert.ok(stream_create_subscribers_data.must_be_subscribed(me.user_id));
-    assert.ok(!stream_create_subscribers_data.must_be_subscribed(test_user101.user_id));
-    override(current_user, "is_admin", true);
-    assert.ok(!stream_create_subscribers_data.must_be_subscribed(me.user_id));
-    assert.ok(!stream_create_subscribers_data.must_be_subscribed(test_user101.user_id));
 });
 
 test("sync_user_ids", () => {
-    // sync_user_ids should not remove current user if already present.
     stream_create_subscribers_data.initialize_with_current_user();
     stream_create_subscribers_data.sync_user_ids([test_user101.user_id, test_user102.user_id]);
-    assert.deepEqual(stream_create_subscribers_data.sorted_user_ids(), [
-        me.user_id,
-        test_user101.user_id,
-        test_user102.user_id,
-    ]);
-
-    // sync_user_ids should not add current user if already not present.
-    stream_create_subscribers_data.remove_user_ids([me.user_id]);
-    stream_create_subscribers_data.sync_user_ids([test_user101.user_id, test_user102.user_id]);
     assert.deepEqual(stream_create_subscribers_data.sorted_user_ids(), [
         test_user101.user_id,
         test_user102.user_id,