fix(ui): keep the alarm create button disabled while the required title is empty

ui/app/manager/src/pages/page-alarms.ts

@@ -1084,7 +1084,12 @@ export class PageAlarms extends Page<AppStateKeyed> {
         .some((input) => !input.checkValidity());
     }
 
-    if (this.alarm && !this.alarm.title) {
+    // The title is required, and in the create state the model behind the button is
+    // this.creationState.alarmModel, which the edit-state guard (this.alarm) never saw.
+    // Without this check the create button stayed enabled with an empty title, and
+    // pressing it did nothing because the backend guard drops the request.
+    const model = this.alarm ?? this.creationState?.alarmModel;
+    if (!model?.title?.trim()) {
       saveBtn.disabled = true;
     }
   }

ui/app/manager/test/alarms.test.ts

@@ -95,6 +95,30 @@ test("should change the status of an existing alarm", async ({ manager, alarmsPa
   expect(stored.status).toBe(AlarmStatus.IN_PROGRESS);
 });
 
+/**
+ * @given Logged into the "master" realm as "admin"
+ * @when A new alarm is started and a property is changed before the required title is filled in
+ * @then The create button stays disabled until the title has content
+ */
+test("should keep the create button disabled while the required title is empty", async ({ manager, alarmsPage }) => {
+  await manager.goToRealmStartPage("master");
+  await alarmsPage.goto();
+  await alarmsPage.getAddButton().click();
+
+  // Changing a property fired onAlarmChanged, which used to re-enable the button even with an
+  // empty title, because the guard only looked at the model of an edited alarm and never at the
+  // model being created.
+  await alarmsPage.setStatus("Resolved");
+  await expect(alarmsPage.getSaveButton()).toBeDisabled();
+
+  // Filling in the title unlocks the button, and emptying it again locks it back down
+  await alarmsPage.getTitleInput().fill("E2E alarm with a title");
+  await expect(alarmsPage.getSaveButton()).toBeEnabled();
+
+  await alarmsPage.getTitleInput().fill("");
+  await expect(alarmsPage.getSaveButton()).toBeDisabled();
+});
+
 /**
  * @given Logged into the "master" realm as "admin"
  * @and An open alarm seeded via REST

ui/app/manager/test/fixtures/pages/alarms.ts

@@ -148,6 +148,15 @@ export class AlarmsPage implements BasePage {
     return this.page.locator("#savebtn");
   }
 
+  /** The required title field in the details panel of the single-alarm view. */
+  getTitleInput(): Locator {
+    return this.page
+      .locator("#details-panel")
+      .locator("or-vaadin-text-field")
+      .filter({ has: this.page.locator('or-translate[value="alarm.title"]') })
+      .locator("input");
+  }
+
   /** Open the single-alarm view of the (first) row containing the given text. */
   async openAlarmByText(text: string) {
     await this.getRowByText(text).first().click();