jest.setup.js

// jest.setup.js
import "@testing-library/jest-dom/extend-expect";

// polyfill for node
import { TextDecoderStream } from "@stardazed/streams-text-encoding";
import { TextDecoder, TextEncoder } from "util";
import { ReadableStream } from "web-streams-polyfill/es6";

global.TextEncoder = TextEncoder;
global.TextDecoderStream = TextDecoderStream;
global.TextDecoder = TextDecoder;
global.ReadableStream = ReadableStream;

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: () => {},
  },
}));