DEV: Move discourse-chat to the core repo. (#18776)

As part of this move, we are also renaming `discourse-chat` to `chat`.

plugins/chat/test/javascripts/components/chat-user-display-name-test.js

@@ -0,0 +1,76 @@
+import componentTest, {
+  setupRenderingTest,
+} from "discourse/tests/helpers/component-test";
+import { query } from "discourse/tests/helpers/qunit-helpers";
+import hbs from "htmlbars-inline-precompile";
+import { module } from "qunit";
+
+function displayName() {
+  return query(".chat-user-display-name").innerText.trim();
+}
+
+module(
+  "Discourse Chat | Component | chat-user-display-name | prioritize username in UX",
+  function (hooks) {
+    setupRenderingTest(hooks);
+
+    componentTest("username and no name", {
+      template: hbs`{{chat-user-display-name user=user}}`,
+
+      async beforeEach() {
+        this.siteSettings.prioritize_username_in_ux = true;
+        this.set("user", { username: "bob", name: null });
+      },
+
+      async test(assert) {
+        assert.equal(displayName(), "bob");
+      },
+    });
+
+    componentTest("username and name", {
+      template: hbs`{{chat-user-display-name user=user}}`,
+
+      async beforeEach() {
+        this.siteSettings.prioritize_username_in_ux = true;
+        this.set("user", { username: "bob", name: "Bobcat" });
+      },
+
+      async test(assert) {
+        assert.equal(displayName(), "bob — Bobcat");
+      },
+    });
+  }
+);
+
+module(
+  "Discourse Chat | Component | chat-user-display-name | prioritize name in UX",
+  function (hooks) {
+    setupRenderingTest(hooks);
+
+    componentTest("no name", {
+      template: hbs`{{chat-user-display-name user=user}}`,
+
+      async beforeEach() {
+        this.siteSettings.prioritize_username_in_ux = false;
+        this.set("user", { username: "bob", name: null });
+      },
+
+      async test(assert) {
+        assert.equal(displayName(), "bob");
+      },
+    });
+
+    componentTest("name and username", {
+      template: hbs`{{chat-user-display-name user=user}}`,
+
+      async beforeEach() {
+        this.siteSettings.prioritize_username_in_ux = false;
+        this.set("user", { username: "bob", name: "Bobcat" });
+      },
+
+      async test(assert) {
+        assert.equal(displayName(), "Bobcat — bob");
+      },
+    });
+  }
+);