Follow-up: revert ultimate fallback to undefined in computeEntityEntryName (#26629)

src/common/entity/compute_entity_name.ts

@@ -31,7 +31,7 @@ export const computeEntityEntryName = (
     entry.name ||
     ("original_name" in entry && entry.original_name != null
       ? String(entry.original_name)
-      : "");
+      : undefined);
 
   const device = entry.device_id ? hass.devices[entry.device_id] : undefined;
 

test/common/entity/compute_entity_name.test.ts

@@ -159,4 +159,25 @@ describe("computeEntityEntryName", () => {
     expect(computeEntityEntryName(entry as any, hass as any)).toBe("2");
     vi.restoreAllMocks();
   });
+
+  it("returns undefined when entity has device but no name or original_name", () => {
+    vi.spyOn(computeDeviceNameModule, "computeDeviceName").mockReturnValue(
+      "Kitchen Device"
+    );
+
+    const entry = {
+      entity_id: "sensor.kitchen_sensor",
+      // No name property
+      // No original_name property
+      device_id: "dev1",
+    };
+    const hass = {
+      devices: { dev1: {} },
+      states: {},
+    };
+
+    // Should return undefined to maintain function contract
+    expect(computeEntityEntryName(entry as any, hass as any)).toBeUndefined();
+    vi.restoreAllMocks();
+  });
 });