insomnia/packages/insomnia-app/app/__jest__/setup.ts

const localStorageMock: Storage = (function() {
  let store: Record<string, string> = {};
  return {
    get length() {
      return Object.keys(store).length;
    },

    clear() {
      store = {};
    },

    getItem(key: string) {
      return store[key];
    },

    key() {
      return null;
    },

    removeItem(key: string) {
      delete store[key];
    },

    setItem(key: string, value: string) {
      store[key] = value.toString();
    },
  };
})();

global.__DEV__ = false;
global.localStorage = localStorageMock;

global.requestAnimationFrame = (callback: FrameRequestCallback) => {
  process.nextTick(callback);
  // note: the spec indicates that the return of this function (the request id) is a non-zero number.  hopefully returning 0 here will indicate that this is a mock if the return is ever to be used accidentally.
  return 0;
};

global.require = require;
// Don't console log real logs that start with a tag (eg. [db] ...). It's annoying
const log = console.log;

global.console.log = (...args) => {
  if (!(typeof args[0] === 'string' && args[0][0] === '[')) {
    log(...args);
  }
};