Adonis.js is a rapidly growing Node.js framework that supports test-driven development (TDD) by incorporating a specialized testing framework. The tutorial explains how to automate testing for an Adonis.js API using continuous integration with CircleCI, ensuring that tests run automatically whenever the codebase changes. It guides users through prerequisites, such as having Node.js and Adonis.js CLI installed, and setting up a CircleCI and GitHub account. The tutorial includes steps to clone the API project, configure the environment, set up a database, and run migrations. It demonstrates how to create and test user-related API endpoints using Postman and the built-in Japa API client plugin. Users are instructed on writing and running tests to verify the functionality of the API, and then integrating the project with CircleCI by creating a configuration file that automates the testing process. The tutorial emphasizes the benefits of TDD in streamlining development workflows and concludes by highlighting how Adonis.js and CircleCI facilitate the adoption of TDD practices.