From 21b0cab3d207879258ec8217cf83930fd739ac2d Mon Sep 17 00:00:00 2001
From: Tom Lienard <tom.lienrd@gmail.com>
Date: Fri, 29 Jul 2022 18:57:03 +0200
Subject: [PATCH] test: useI18n 100% coverage (#17)

---
 .../__tests__/use-i18n.test.tsx               | 69 +++++++++++++++++--
 .../src/i18n/create-i18n-provider.tsx         |  4 +-
 2 files changed, 64 insertions(+), 9 deletions(-)

diff --git a/packages/next-international/__tests__/use-i18n.test.tsx b/packages/next-international/__tests__/use-i18n.test.tsx
index b129813..7d9cdfc 100644
--- a/packages/next-international/__tests__/use-i18n.test.tsx
+++ b/packages/next-international/__tests__/use-i18n.test.tsx
@@ -6,11 +6,20 @@ import en from './utils/en';
 
 beforeEach(() => {
   vi.mock('next/router', () => ({
-    useRouter: vi.fn().mockImplementation(() => ({
-      locale: 'en',
-      defaultLocale: 'en',
-      locales: ['en', 'fr'],
-    })),
+    useRouter: vi
+      .fn()
+      .mockImplementationOnce(() => ({
+        locales: ['en', 'fr'],
+      }))
+      .mockImplementationOnce(() => ({
+        locale: 'en',
+        defaultLocale: 'en',
+      }))
+      .mockImplementation(() => ({
+        locale: 'en',
+        defaultLocale: 'en',
+        locales: ['en', 'fr'],
+      })),
   }));
 });
 
@@ -19,7 +28,55 @@ afterEach(() => {
 });
 
 describe('useI18n', () => {
-  it('should thrown if not used inside I18nProvider', () => {
+  it('should log error if locale not set in next.config.js', () => {
+    const spy = vi.spyOn(console, 'error').mockImplementation(() => null);
+    const { useI18n, I18nProvider } = createI18n<typeof import('./utils/en').default>({
+      en: () => import('./utils/en'),
+      fr: () => import('./utils/fr'),
+    });
+
+    function App() {
+      const { t } = useI18n();
+
+      return <p>{t('hello')}</p>;
+    }
+
+    render(
+      <I18nProvider locale={en}>
+        <App />
+      </I18nProvider>,
+    );
+    expect(console.error).toHaveBeenCalledWith(
+      "[next-international] 'i18n.defaultLocale' not defined in 'next.config.js'",
+    );
+
+    spy.mockReset();
+  });
+
+  it('should log error if locales not set in next.config.js', () => {
+    const spy = vi.spyOn(console, 'error').mockImplementation(() => null);
+    const { useI18n, I18nProvider } = createI18n<typeof import('./utils/en').default>({
+      en: () => import('./utils/en'),
+      fr: () => import('./utils/fr'),
+    });
+
+    function App() {
+      const { t } = useI18n();
+
+      return <p>{t('hello')}</p>;
+    }
+
+    render(
+      <I18nProvider locale={en}>
+        <App />
+      </I18nProvider>,
+    );
+    expect(console.error).toHaveBeenCalledWith("[next-international] 'i18n.locales' not defined in 'next.config.js'");
+
+    spy.mockReset();
+  });
+
+  it('should throw if not used inside I18nProvider', () => {
     const { useI18n } = createI18n<typeof import('./utils/en').default>({
       en: () => import('./utils/en'),
       fr: () => import('./utils/fr'),
diff --git a/packages/next-international/src/i18n/create-i18n-provider.tsx b/packages/next-international/src/i18n/create-i18n-provider.tsx
index ebce46d..01836bb 100644
--- a/packages/next-international/src/i18n/create-i18n-provider.tsx
+++ b/packages/next-international/src/i18n/create-i18n-provider.tsx
@@ -46,9 +46,7 @@ export function createI18nProvider<Locale extends BaseLocale>(
         return;
       }
 
-      const load = locales[locale] || locales[defaultLocale];
-
-      load().then(content => {
+      locales[locale]().then(content => {
         setClientLocale(content.default as Locale);
       });
     }, [locale, defaultLocale]);