test: add i18n test

jest/setupFiles.js

@@ -2,6 +2,7 @@
 import "react-native-gesture-handler/jestSetup";
 
 import mockClipboard from "@react-native-clipboard/clipboard/jest/clipboard-mock.js";
+import mockBackHandler from "react-native/Libraries/Utilities/__mocks__/BackHandler.js";
 
 // include this section and the NativeAnimatedHelper section for mocking react-native-reanimated
 jest.mock("react-native-reanimated", () => {
@@ -50,6 +51,17 @@ jest.mock("react-i18next", () => ({
 	},
 }));
 
+jest.mock("i18next", () => ({
+	changeLanguage: jest.fn(),
+	use: jest.fn().mockReturnThis(), // Add this line to mock the use method
+	init: jest.fn().mockReturnThis(), // Add this line to mock the init method
+}));
+
+jest.mock(
+	"react-native/Libraries/Utilities/BackHandler",
+	() => mockBackHandler
+);
+
 jest.mock("react-native-responsive-fontsize", () => ({
 	RFValue: jest.fn().mockImplementation(() => 10),
 	RFPercentage: jest.fn().mockImplementation(() => 10),

src/utils/__tests__/translations/i18n.test.ts

@@ -0,0 +1,124 @@
+import AsyncStorage from "@react-native-async-storage/async-storage";
+
+import i18n from "../../translations/i18n";
+
+describe("i18n", () => {
+	beforeEach(() => {
+		jest.clearAllMocks();
+		AsyncStorage.clear();
+	});
+
+	afterEach(() => {
+		jest.resetAllMocks();
+	});
+	it("should throw an error if no locales are found", () => {
+		jest.resetModules();
+
+		jest.mock("react-native-localize", () => ({
+			getLocales: jest.fn(),
+		}));
+
+		expect(() => {
+			require("../../translations/i18n");
+		}).toThrow("No locales found");
+	});
+
+	const resources = {
+		en: {},
+		ru: {},
+		ptBR: {},
+		sk: {},
+		sl: {},
+		srLatn: {},
+		sr: {},
+		sv: {},
+		sw: {},
+		th: {},
+		tr: {},
+		uk: {},
+		ur: {},
+		vi: {},
+		zh: {},
+		zhHans: {},
+		zhHant: {},
+		klingon: {},
+	};
+
+	it("should return languageWithoutHyphen if it exists in resources", () => {
+		const languageWithoutHyphen = "ptBR";
+
+		const languageCode = "pt";
+
+		const result = Object.keys(resources).includes(languageWithoutHyphen)
+			? languageWithoutHyphen
+			: languageCode !== null && Object.keys(resources).includes(languageCode)
+			? languageCode
+			: "en";
+
+		expect(result).toBe(languageWithoutHyphen);
+	});
+
+	it('should return "en" if languageWithoutHyphen does not exist in resources and languageCode is null', () => {
+		const languageWithoutHyphen = "nonexistent";
+		const languageCode = null;
+
+		const result = Object.keys(resources).includes(languageWithoutHyphen)
+			? languageWithoutHyphen
+			: languageCode !== null && Object.keys(resources).includes(languageCode)
+			? languageCode
+			: "en";
+
+		expect(result).toBe("en");
+	});
+
+	it("should return languageCode if languageWithoutHyphen does not exist in resources but languageCode does", () => {
+		const languageWithoutHyphen = "nonexistent";
+
+		const languageCode = "ru";
+
+		const result = Object.keys(resources).includes(languageWithoutHyphen)
+			? languageWithoutHyphen
+			: languageCode !== null && Object.keys(resources).includes(languageCode)
+			? languageCode
+			: "en";
+
+		expect(result).toBe(languageCode);
+	});
+
+	it("should change language to stored language", async () => {
+		jest.mock("react-native-localize", () => ({
+			getLocales: () => [
+				{ languageCode: "en", languageTag: "en-US", countryCode: "US" },
+			],
+		}));
+
+		const storedLanguageMock = "es"; // idioma armazenado simulado
+		(AsyncStorage.getItem as jest.Mock).mockResolvedValue(storedLanguageMock);
+
+		await (async () => {
+			const storedLanguage = await AsyncStorage.getItem("selectedLanguage");
+			storedLanguage && i18n.changeLanguage(storedLanguage);
+		})();
+
+		expect(AsyncStorage.getItem).toHaveBeenCalledWith("selectedLanguage");
+		expect(i18n.changeLanguage).toHaveBeenCalledWith(storedLanguageMock);
+	});
+
+	it("should not change language if no stored language", async () => {
+		jest.mock("react-native-localize", () => ({
+			getLocales: () => [
+				{ languageCode: "en", languageTag: "en-US", countryCode: "US" },
+			],
+		}));
+
+		(AsyncStorage.getItem as jest.Mock).mockResolvedValue(null);
+
+		await (async () => {
+			const storedLanguage = await AsyncStorage.getItem("selectedLanguage");
+			storedLanguage && i18n.changeLanguage(storedLanguage);
+		})();
+
+		expect(AsyncStorage.getItem).toHaveBeenCalledWith("selectedLanguage");
+		expect(i18n.changeLanguage).not.toHaveBeenCalled();
+	});
+});

src/utils/translations/i18n.ts

@@ -121,7 +121,7 @@ const resources = {
 
 const lngChecked = Object.keys(resources).includes(languageWithoutHyphen)
 	? languageWithoutHyphen
-	: Object.keys(resources).includes(languageCode)
+	: languageCode !== null && Object.keys(resources).includes(languageCode)
 	? languageCode
 	: "en";