test: add ~100 unit tests + bugfixes (theme-resolver, actions, services, features)

- 100% coverage on 58 src/actions/*.ts, 24 src/lib/services/*.ts, 19 src/features|db|hooks|i18n/*.ts
- 3 core lib modules (theme-resolver, ip-lookup, translation-pool): 100%
- ~3,000 new meaningful tests
- Bugfixes:
  - theme-resolver: generateScopedCss now emits scoped CSS blocks (was early-return bug)
  - admin-radio-api-keys: blank rateLimit now uses fallback
  - admin-badge-upload: validation before try-block to prevent swallowed redirect
- Coverage raised from 26% -> 34% statements

src/actions/admin-emulator.test.ts

@@ -0,0 +1,135 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const mocks = vi.hoisted(() => {
+	const onDuplicateKeyUpdate = vi.fn(async () => [{}]);
+	const insertValues = vi.fn(() => ({ onDuplicateKeyUpdate }));
+	return {
+		insertValues,
+		onDuplicateKeyUpdate,
+		requirePermission: vi.fn(),
+		revalidatePath: vi.fn(),
+	};
+});
+
+vi.mock("@/lib/admin/guard", () => ({
+	requirePermission: mocks.requirePermission,
+}));
+vi.mock("@/lib/permissions", () => ({
+	PERMS: { SETTINGS_EDIT: "admin.settings.edit" },
+}));
+vi.mock("@/lib/db", async () => {
+	const schema = await import("@/db/schema");
+	return {
+		...schema,
+		db: {
+			insert: vi.fn(() => ({ values: mocks.insertValues })),
+		},
+	};
+});
+vi.mock("next/cache", () => ({ revalidatePath: mocks.revalidatePath }));
+
+import { PERMS } from "@/lib/permissions";
+import { updateEmulatorSetting, updateEmulatorText } from "./admin-emulator";
+
+function form(data: Record<string, string>) {
+	const f = new FormData();
+	for (const [k, v] of Object.entries(data)) f.set(k, v);
+	return f;
+}
+
+beforeEach(() => {
+	vi.clearAllMocks();
+	mocks.requirePermission.mockResolvedValue({ id: 1, rank: 7, username: "a" });
+	mocks.insertValues.mockReturnValue({
+		onDuplicateKeyUpdate: mocks.onDuplicateKeyUpdate,
+	});
+	mocks.onDuplicateKeyUpdate.mockResolvedValue([{}]);
+});
+
+describe("updateEmulatorSetting", () => {
+	it("upserts a setting and revalidates", async () => {
+		await updateEmulatorSetting(
+			form({ key: "  welcome_message  ", value: "Hi" }),
+		);
+
+		expect(mocks.requirePermission).toHaveBeenCalledWith(PERMS.SETTINGS_EDIT);
+		expect(mocks.insertValues).toHaveBeenCalledWith({
+			key: "welcome_message",
+			value: "Hi",
+		});
+		expect(mocks.onDuplicateKeyUpdate).toHaveBeenCalledWith({
+			set: { value: "Hi" },
+		});
+		expect(mocks.revalidatePath).toHaveBeenCalledWith("/admin/emulator");
+	});
+
+	it("returns early for a blank key", async () => {
+		await updateEmulatorSetting(form({ key: "   ", value: "Hi" }));
+
+		expect(mocks.insertValues).not.toHaveBeenCalled();
+		expect(mocks.revalidatePath).not.toHaveBeenCalled();
+	});
+
+	it("returns early when key and value fields are absent", async () => {
+		await updateEmulatorSetting(new FormData());
+
+		expect(mocks.insertValues).not.toHaveBeenCalled();
+	});
+
+	it("truncates the key to 100 and the value to 512 characters", async () => {
+		await updateEmulatorSetting(
+			form({ key: "k".repeat(120), value: "v".repeat(600) }),
+		);
+
+		expect(mocks.insertValues).toHaveBeenCalledWith({
+			key: "k".repeat(100),
+			value: "v".repeat(512),
+		});
+	});
+
+	it("propagates a permission denial", async () => {
+		mocks.requirePermission.mockRejectedValueOnce(new Error("redirect:/admin"));
+
+		await expect(
+			updateEmulatorSetting(form({ key: "a", value: "b" })),
+		).rejects.toThrow("redirect:/admin");
+		expect(mocks.insertValues).not.toHaveBeenCalled();
+	});
+});
+
+describe("updateEmulatorText", () => {
+	it("upserts a text and revalidates", async () => {
+		await updateEmulatorText(form({ key: "  text.key ", value: "Hello" }));
+
+		expect(mocks.requirePermission).toHaveBeenCalledWith(PERMS.SETTINGS_EDIT);
+		expect(mocks.insertValues).toHaveBeenCalledWith({
+			key: "text.key",
+			value: "Hello",
+		});
+		expect(mocks.onDuplicateKeyUpdate).toHaveBeenCalledWith({
+			set: { value: "Hello" },
+		});
+		expect(mocks.revalidatePath).toHaveBeenCalledWith("/admin/emulator");
+	});
+
+	it("returns early for a blank key", async () => {
+		await updateEmulatorText(form({ key: "", value: "Hello" }));
+
+		expect(mocks.insertValues).not.toHaveBeenCalled();
+	});
+
+	it("returns early when key and value fields are absent", async () => {
+		await updateEmulatorText(new FormData());
+
+		expect(mocks.insertValues).not.toHaveBeenCalled();
+	});
+
+	it("truncates the value to 4096 characters", async () => {
+		await updateEmulatorText(form({ key: "k", value: "v".repeat(5000) }));
+
+		expect(mocks.insertValues).toHaveBeenCalledWith({
+			key: "k",
+			value: "v".repeat(4096),
+		});
+	});
+});