diff --git a/test/common/entity/compute_area_name.test.ts b/test/common/entity/compute_area_name.test.ts
new file mode 100644
index 0000000000..cd02371ad2
--- /dev/null
+++ b/test/common/entity/compute_area_name.test.ts
@@ -0,0 +1,29 @@
+import { describe, expect, it } from "vitest";
+import { computeAreaName } from "../../../src/common/entity/compute_area_name";
+import type { AreaRegistryEntry } from "../../../src/data/area_registry";
+
+describe("computeAreaName", () => {
+  it("returns the trimmed name if present", () => {
+    const area: AreaRegistryEntry = {
+      name: "Living Room",
+    } as AreaRegistryEntry;
+    expect(computeAreaName(area)).toBe("Living Room");
+  });
+
+  it("trims whitespace from the name", () => {
+    const area: AreaRegistryEntry = {
+      name: "  Kitchen  ",
+    } as AreaRegistryEntry;
+    expect(computeAreaName(area)).toBe("Kitchen");
+  });
+
+  it("returns undefined if name is missing", () => {
+    const area: AreaRegistryEntry = {} as AreaRegistryEntry;
+    expect(computeAreaName(area)).toBeUndefined();
+  });
+
+  it("returns empty string if name is only whitespace", () => {
+    const area: AreaRegistryEntry = { name: "   " } as AreaRegistryEntry;
+    expect(computeAreaName(area)).toBe("");
+  });
+});
diff --git a/test/common/entity/compute_device_name.test.ts b/test/common/entity/compute_device_name.test.ts
new file mode 100644
index 0000000000..459374e047
--- /dev/null
+++ b/test/common/entity/compute_device_name.test.ts
@@ -0,0 +1,130 @@
+import { describe, expect, it, vi } from "vitest";
+import {
+  computeDeviceName,
+  computeDeviceNameDisplay,
+  fallbackDeviceName,
+  getDuplicatedDeviceNames,
+} from "../../../src/common/entity/compute_device_name";
+
+describe("computeDeviceName", () => {
+  it("returns name_by_user if present", () => {
+    expect(
+      computeDeviceName({
+        name_by_user: "User Name",
+        name: "Device Name",
+      } as any)
+    ).toBe("User Name");
+  });
+
+  it("returns name if name_by_user is not present", () => {
+    expect(computeDeviceName({ name: "Device Name" } as any)).toBe(
+      "Device Name"
+    );
+    expect(
+      computeDeviceName({ name_by_user: "", name: "Device Name" } as any)
+    ).toBe("Device Name");
+  });
+
+  it("returns undefined if neither name_by_user nor name is present", () => {
+    expect(computeDeviceName({} as any)).toBeUndefined();
+  });
+
+  it("trims whitespace", () => {
+    expect(computeDeviceName({ name_by_user: "  User Name  " } as any)).toBe(
+      "User Name"
+    );
+  });
+});
+
+describe("computeDeviceNameDisplay", () => {
+  const hass = {
+    localize: vi.fn((key, params) => {
+      if (key === "ui.panel.config.devices.unnamed_device") {
+        return `Unnamed (${params?.type})`;
+      }
+      if (key.startsWith("ui.panel.config.devices.type.")) {
+        return key.split(".").pop();
+      }
+      return key;
+    }),
+    states: {
+      "light.test": {
+        entity_id: "light.test",
+        attributes: { friendly_name: "Test Light" },
+      },
+    },
+  } as any;
+
+  it("returns device name if present", () => {
+    expect(computeDeviceNameDisplay({ name: "Device" } as any, hass)).toBe(
+      "Device"
+    );
+  });
+
+  it("returns fallback name from entities if device name not present", () => {
+    const entities: any = [{ entity_id: "light.test" }];
+    expect(computeDeviceNameDisplay({} as any, hass, entities)).toBe(
+      "Test Light"
+    );
+  });
+
+  it("returns localized unnamed device if no name or entities", () => {
+    expect(
+      computeDeviceNameDisplay({ entry_type: "router" } as any, hass)
+    ).toBe("Unnamed (router)");
+  });
+});
+
+describe("fallbackDeviceName", () => {
+  const hass = {
+    states: {
+      "sensor.temp": {
+        entity_id: "sensor.temp",
+        attributes: { friendly_name: "Temperature" },
+      },
+      "light.lamp": {
+        entity_id: "light.lamp",
+        attributes: { friendly_name: "Lamp" },
+      },
+    },
+  } as any;
+
+  it("returns the first entity's friendly name", () => {
+    const entities: any = [
+      { entity_id: "sensor.temp" },
+      { entity_id: "light.lamp" },
+    ];
+    expect(fallbackDeviceName(hass, entities)).toBe("Temperature");
+  });
+
+  it("returns undefined if no entities have state", () => {
+    expect(
+      fallbackDeviceName({ states: {} } as any, [{ entity_id: "none" } as any])
+    ).toBeUndefined();
+  });
+
+  it("works with string entity ids", () => {
+    expect(fallbackDeviceName(hass, ["light.lamp"])).toBe("Lamp");
+  });
+});
+
+describe("getDuplicatedDeviceNames", () => {
+  it("returns a set of duplicated device names", () => {
+    const devices: any = {
+      a: { name: "Device" },
+      b: { name: "Device" },
+      c: { name: "Unique" },
+    };
+    const result = getDuplicatedDeviceNames(devices);
+    expect(result.has("Device")).toBe(true);
+    expect(result.has("Unique")).toBe(false);
+  });
+
+  it("returns empty set if no duplicates", () => {
+    const devices = {
+      a: { name: "A" },
+      b: { name: "B" },
+    };
+    expect(getDuplicatedDeviceNames(devices as any).size).toBe(0);
+  });
+});
diff --git a/test/common/entity/compute_entity_name.test.ts b/test/common/entity/compute_entity_name.test.ts
new file mode 100644
index 0000000000..978e009dc3
--- /dev/null
+++ b/test/common/entity/compute_entity_name.test.ts
@@ -0,0 +1,137 @@
+import { describe, expect, it, vi } from "vitest";
+import * as computeDeviceNameModule from "../../../src/common/entity/compute_device_name";
+import {
+  computeEntityEntryName,
+  computeEntityName,
+} from "../../../src/common/entity/compute_entity_name";
+import * as computeStateNameModule from "../../../src/common/entity/compute_state_name";
+import * as stripPrefixModule from "../../../src/common/entity/strip_prefix_from_entity_name";
+
+describe("computeEntityName", () => {
+  it("returns state name if entity not in registry", () => {
+    vi.spyOn(computeStateNameModule, "computeStateName").mockReturnValue(
+      "Kitchen Light"
+    );
+    const stateObj = {
+      entity_id: "light.kitchen",
+      attributes: { friendly_name: "Kitchen Light" },
+      state: "on",
+    };
+    const hass = {
+      entities: {},
+      devices: {},
+      states: {
+        "light.kitchen": stateObj,
+      },
+    };
+    expect(computeEntityName(stateObj as any, hass as any)).toBe(
+      "Kitchen Light"
+    );
+    vi.restoreAllMocks();
+  });
+
+  it("returns entity entry name if present", () => {
+    const stateObj = {
+      entity_id: "light.kitchen",
+      attributes: {},
+      state: "on",
+    };
+    const hass = {
+      entities: {
+        "light.kitchen": {
+          entity_id: "light.kitchen",
+          name: "Ceiling Light",
+        },
+      },
+      devices: {},
+      states: {
+        "light.kitchen": stateObj,
+      },
+    };
+    expect(computeEntityName(stateObj as any, hass as any)).toBe(
+      "Ceiling Light"
+    );
+  });
+});
+
+describe("computeEntityEntryName", () => {
+  it("returns entry.name if no device", () => {
+    const entry = { entity_id: "light.kitchen", name: "Ceiling Light" };
+    const hass = { devices: {}, states: {} };
+    expect(computeEntityEntryName(entry as any, hass as any)).toBe(
+      "Ceiling Light"
+    );
+  });
+
+  it("returns device-stripped name if device present", () => {
+    vi.spyOn(computeDeviceNameModule, "computeDeviceName").mockReturnValue(
+      "Kitchen"
+    );
+    vi.spyOn(stripPrefixModule, "stripPrefixFromEntityName").mockImplementation(
+      (name, prefix) => name.replace(prefix + " ", "")
+    );
+    const entry = {
+      entity_id: "light.kitchen",
+      name: "Kitchen Light",
+      device_id: "dev1",
+    };
+    const hass = {
+      devices: { dev1: {} },
+      states: {},
+    };
+    expect(computeEntityEntryName(entry as any, hass as any)).toBe("Light");
+    vi.restoreAllMocks();
+  });
+
+  it("returns undefined if device name equals entity name", () => {
+    vi.spyOn(computeDeviceNameModule, "computeDeviceName").mockReturnValue(
+      "Kitchen Light"
+    );
+    const entry = {
+      entity_id: "light.kitchen",
+      name: "Kitchen Light",
+      device_id: "dev1",
+    };
+    const hass = {
+      devices: { dev1: {} },
+      states: {},
+    };
+    expect(computeEntityEntryName(entry as any, hass as any)).toBeUndefined();
+    vi.restoreAllMocks();
+  });
+
+  it("falls back to state name if no name and no device", () => {
+    vi.spyOn(computeStateNameModule, "computeStateName").mockReturnValue(
+      "Fallback Name"
+    );
+    const entry = { entity_id: "light.kitchen" };
+    const hass = {
+      devices: {},
+      states: {
+        "light.kitchen": { entity_id: "light.kitchen" },
+      },
+    };
+    expect(computeEntityEntryName(entry as any, hass as any)).toBe(
+      "Fallback Name"
+    );
+    vi.restoreAllMocks();
+  });
+
+  it("returns original_name if present", () => {
+    const entry = { entity_id: "light.kitchen", original_name: "Old Name" };
+    const hass = {
+      devices: {},
+      states: {},
+    };
+    expect(computeEntityEntryName(entry as any, hass as any)).toBe("Old Name");
+  });
+
+  it("returns undefined if no name, original_name, or device", () => {
+    const entry = { entity_id: "light.kitchen" };
+    const hass = {
+      devices: {},
+      states: {},
+    };
+    expect(computeEntityEntryName(entry as any, hass as any)).toBeUndefined();
+  });
+});
diff --git a/test/common/entity/compute_floor_name.test.ts b/test/common/entity/compute_floor_name.test.ts
new file mode 100644
index 0000000000..6cdd78f147
--- /dev/null
+++ b/test/common/entity/compute_floor_name.test.ts
@@ -0,0 +1,25 @@
+import { describe, expect, it } from "vitest";
+import { computeFloorName } from "../../../src/common/entity/compute_floor_name";
+import type { FloorRegistryEntry } from "../../../src/data/floor_registry";
+
+describe("computeFloorName", () => {
+  it("returns the trimmed name if present", () => {
+    const floor: FloorRegistryEntry = { name: "Living Room" } as any;
+    expect(computeFloorName(floor)).toBe("Living Room");
+  });
+
+  it("trims whitespace from the name", () => {
+    const floor: FloorRegistryEntry = { name: "  Upstairs  " } as any;
+    expect(computeFloorName(floor)).toBe("Upstairs");
+  });
+
+  it("returns empty string if name is empty", () => {
+    const floor: FloorRegistryEntry = { name: "" } as any;
+    expect(computeFloorName(floor)).toBe("");
+  });
+
+  it("returns undefined if name is undefined", () => {
+    const floor: FloorRegistryEntry = { name: undefined } as any;
+    expect(computeFloorName(floor)).toBeUndefined();
+  });
+});