You will learn the best practices to follow to write useful and lasting tests and how to write effective end-to-end tests (E2E).

React App Testing

This module will provide you with requisite information, principles, and experience-based advice that you need to enter the world of testing methodologies.

You will learn the best practices to follow to write useful and lasting tests, how to test different user flows without a working back-end, how to write effective end-to-end tests (E2E), and finally, how to integrate tests into development and Continuous Integration pipelines.

At the end of the module, you will be able to apply the fundamental principles of the test methodologies to understand what to test and how do it effectively.

Front-end Testing 101: Integration and End-to-end Testing

Cypress has a [dedicated CI page](https://docs.cypress.io/guides/continuous-integration/introduction) on its site with configurations for different providers. Cypress can be run with its UI (`npx cypress open`) or in headless mode (`npx cypress run`).The only thing you need to do islaunch the front-end server, and when the server is up and running, launch Cypress in headless mode.


The most used package is start-server-and-test which allows you to “Start, serve, and test.” Take a look at the test script:
```json
"scripts": {
  "test": "start-server-and-test realworld:start http://localhost:4100 cy:run"
}
```

Run the `realworld:start` script and, when the `http://localhost:4100` endpoint becomes available, launch the `cy:run` script.

Cypress has its own Dashboard product that allows for easy navigation between all test runs,  single tests, and test results. This allows you to parallelize the test runs and host the test videos.


Let's learn about continuous integration in Cypress.

Introduction

E2E Testing

The First E2E Test

Polishing the E2E test

Ajax Requests

Custom Commands

UI Integration Tests

Other Best Practices

Bonus Section

Appendix

Conclusion

Continuous Integration