How to automate testing for a React application with GitLab

What this post added

This post details how to configure GitLab CI/CD to automate the testing of a React application. It covers setting up a React app with Create React App, running Jest tests locally, and configuring a `.gitlab-ci.yml` file to execute tests in a CI pipeline. Key technical details include using `jest-junit` to generate JUnit reports, configuring the `test:ci` script in `package.json` for CI environments with coverage collection, and defining a CI job to run tests, upload coverage artifacts, and report JUnit results.