FIX: allows to change sound when no sound was ever set (#19136)

It fixes a bug which was only allowing users with a sound to change it. Users with `none` could not change it again after a full page reset.

plugins/chat/test/javascripts/acceptance/chat-preferences-test.js

@@ -0,0 +1,34 @@
+import { acceptance } from "discourse/tests/helpers/qunit-helpers";
+import { visit } from "@ember/test-helpers";
+import { test } from "qunit";
+import { chatChannels } from "discourse/plugins/chat/chat-fixtures";
+import selectKit from "discourse/tests/helpers/select-kit-helper";
+import { CHAT_SOUNDS } from "discourse/plugins/chat/discourse/services/chat-audio-manager";
+
+function preferencesPretender(server, helper) {
+  server.get("/u/eviltrout/activity.json", () => helper.response({}));
+  server.get("/chat/chat_channels.json", () => helper.response(chatChannels));
+}
+
+acceptance("Discourse Chat | User Preferences", function (needs) {
+  needs.user({ can_chat: true, has_chat_enabled: true });
+  needs.settings({ chat_enabled: true });
+  needs.pretender(preferencesPretender);
+
+  test("when user has not chat sound set", async function (assert) {
+    const sounds = Object.keys(CHAT_SOUNDS);
+    await visit("/u/eviltrout/preferences/chat");
+    const dropdown = selectKit("#user_chat_sounds");
+
+    assert.strictEqual(dropdown.header().value(), null, "it displays no sound");
+
+    await dropdown.expand();
+    await dropdown.selectRowByValue(sounds[1]);
+
+    assert.strictEqual(
+      dropdown.header().value(),
+      sounds[1],
+      "it selects the sound"
+    );
+  });
+});