takethefake

import { useEffect, useReducer } from "react";

export interface QueryArgs<T> {
  url: string;
  options: RequestInit;
  deserialize?: (res: Response) => Promise<T>;
}

export interface QueryAction<T> {
  type: string;

takethefake

// src/__mocks_axios.js

const mockAxios = jest.genMockFromModule('axios')

// this is the key to fix the axios.create() undefined error!
mockAxios.create = jest.fn(() => mockAxios)

export default mockAxios

// example test class which uses axios mock

takethefake

it('will check the matchers and pass', () => {
  const user = {
    createdAt: new Date(),
    id: Math.floor(Math.random() * 20),
    name: 'LeBron James',
  };

  expect(user).toMatchSnapshot({
    createdAt: expect.any(Date),
    id: expect.any(Number),

takethefake

it('renders correctly', () => {
  const tree = renderer
    .create(<Link page="https://prettier.io">Prettier</Link>)
    .toJSON();
  expect(tree).toMatchInlineSnapshot();
});

// Will be changed after one Jest run into: 

it('renders correctly', () => {

takethefake

import React from 'react';
import Link from '../Link.react';
import renderer from 'react-test-renderer';

it('renders correctly', () => {
  const tree = renderer
    .create(<Link page="http://www.facebook.com">Facebook</Link>)
    .toJSON();
  expect(tree).toMatchSnapshot();
});

takethefake

import * as React from "react";
import ReactDOM from "react-dom";
import { Input } from "../";

test("it initializes with a defaultValue", () => {
  const defaultValue = "DefaultValue";
  const wrapper = mount(<Input initialValue={defaultValue} />);
  const input = wrapper.find("input");

  expect(input.instance().value).toBe(defaultValue);

takethefake

/* @flow */
function foo(x: ?number): string {
  if (x) {
    return x;
  }
  return "default string";
}

takethefake

function foo(x: number): string {
  if (x) {
    return x;
  }
  return "default string";
}

takethefake

// posible test
describe("what is the unit under test?", () => {
  it("define a test scenario that should be tested", () => {
    //write your test here
  });
  it("define an other test scenario that should be tested", () => {
    //write your test here
  });
});

takethefake

describe('Vehicle color function',()=>{
  it('should return blue for car',()=>{
    expect(vehicleColor('car')).toBe('blue');
  });
});