Jest has clearly addressed how to mock a module in this link https://jestjs.io/docs/en/manual-mocks#mocking-node-modules. It has an important note as following: Note: In order to mock properly, Jest needs jest.mock(‘moduleName’) to be in the same scope as the require/import statement. On the other hand, Most of use cases jest.mock is supposed to be called at the … Read more
File that exports a constant value that I want to mock: // utils/deviceTypeUtils file import DeviceInfo from ‘react-native-device-info’; export const isTablet = DeviceInfo.isTablet(); In my test file, I use this code to mock the constant isTablet: // file: deviceTypeUtils.spec const DeviceTypeUtilsMock = jest.requireMock(‘../utils/deviceTypeUtils’); jest.mock(‘../utils/deviceTypeUtils’, () => ({ isTablet: false, })); describe(‘mock const example’, () => … Read more
There are multiple mistakes in your test. Passing component type instead of component instance to render // this is wrong, passing component type baseDom = render(cardComponent); // this is right, passing component instance created with JSX baseDom = render(<cardComponent />); Using mouseMove instead of mouseOver event Searching element by title and passing text instead of … Read more
The react hooks testing library docs go more into depth on this. However, what we essentially are missing is the provider which we can obtain by creating a wrapper. First we declare a component which will be our provider: import { Provider } from ‘react-redux’ const ReduxProvider = ({ children, reduxStore }) => ( <Provider … Read more
If you have const x = “Some string” To test for x using regex, getByText(new RegExp(x, “i”))
It looks like you are wanting to verify that handleError gets called when build runs. Private methods are compiled to normal JavaScript prototype methods, so you can use the any type to let the spy creation pass through the TypeScript type checking. Here is a highly simplified example: class OrderBuilder { public build() { this.handleError() … Read more
Those helped me get started: React TDD Guide Using Test Driven Development with React.js to Add Multi-Select to the Drag and Drop Component React TDD Example: Unit Testing and Building a React Component With Jest, Gulp and React Test Utils Testing Flux Applications Awesome React – testing Also worth looking at Shallow Rendering
as @Giorgio mentioned: fireEvent.click(document) //or userEvent.click(document.body);
if you have a line of code that says var x= 10; console.log(x); that’s one line and 2 statements. Statement coverage has each statement in the program been executed. Line coverage has each executable line in the source file been executed.