Fix jest tests by mocking i18n, and prevent future such breakages by …

…making warns and errors fatal

website/jest.setup.js

@@ -1,2 +1,37 @@
 // jest.setup.js
 import "@testing-library/jest-dom/extend-expect";
+
+
+const CONSOLE_FAIL_TYPES = ['error', 'warn'];
+
+// Throw errors when a `console.error` or `console.warn` happens
+// by overriding the functions.
+// If the warning/error is intentional, then catch it and expect for it, like:
+//
+//  jest.spyOn(console, 'warn').mockImplementation();
+//  ...
+//  expect(console.warn).toHaveBeenCalledWith(expect.stringContaining('Empty titles are deprecated.'));
+CONSOLE_FAIL_TYPES.forEach((type) => {
+  const orig_f = console[type];
+  console[type] = (...message) => {
+    orig_f(...message);
+    throw new Error(`Failing due to console.${type} while running test!\n\n${message.join(' ')}`);
+  };
+});
+
+// Mock out useTranslation hook as per https://react.i18next.com/misc/testing
+jest.mock('react-i18next', () => ({
+    // this mock makes sure any components using the translate hook can use it without a warning being shown
+    useTranslation: () => {
+      return {
+        t: (str) => str,
+        i18n: {
+          changeLanguage: () => new Promise(() => {}),
+        },
+      };
+    },
+    initReactI18next: {
+      type: '3rdParty',
+      init: () => {},
+    }
+  }));