Add i18n test

Now the util folder has 100% coverage.

Signed-off-by: Mcat12 <newtoncat12@yahoo.com>

src/util/__tests__/i18n.test.tsx

@@ -0,0 +1,29 @@
+/* Pi-hole: A black hole for Internet advertisements
+ * (c) 2019 Pi-hole, LLC (https://pi-hole.net)
+ * Network-wide ad blocking via your own hardware.
+ *
+ * Web Interface
+ * Test internationalization setup
+ *
+ * This file is copyright under the latest version of the EUPL.
+ * Please see LICENSE file for your rights under this license. */
+
+import { setupI18n } from "../i18n";
+
+// Mock react-i18next, as it does not properly export the i18next module during
+// testing.
+// https://github.com/i18next/react-i18next/issues/434
+jest.mock("react-i18next", () => ({
+  reactI18nextModule: {
+    type: "3rdParty",
+    init: () => {}
+  }
+}));
+
+it("configures i18n successfully", async () => {
+  // Provide a mock ajax function to the XHR backend
+  const fakeAjax = (url: any, options: any, callback: any) => callback("", {});
+
+  // Make sure i18n initializes without error
+  await setupI18n(fakeAjax);
+});

src/util/i18n.tsx

@@ -15,8 +15,13 @@ import { reactI18nextModule } from "react-i18next";
 import config from "../config";
 import languages from "../languages.json";
 
-export function setupI18n() {
-  i18n
+/**
+ * Set up the internationalization service
+ *
+ * @param ajax An optional ajax function to use when fetching translations
+ */
+export function setupI18n(ajax?: any) {
+  return i18n
     .use(XHR)
     .use(LanguageDetector)
     .use(reactI18nextModule)
@@ -46,7 +51,8 @@ export function setupI18n() {
         escapeValue: false
       },
       backend: {
-        loadPath: process.env.PUBLIC_URL + "/i18n/{{lng}}/{{ns}}.json"
+        loadPath: process.env.PUBLIC_URL + "/i18n/{{lng}}/{{ns}}.json",
+        ajax
       },
       react: {
         // Wait until translations are loaded before rendering