In this module we're going to start looking at a practical application of ASTs when needing to maintain and refactor a codebase. Specifically, we want to create a new Button component that will handle all of the button styles and functionality. It will make buttons consistent and allow making global button changes in a single component. However, there are already many usages of button elements.

This module will cover performing a code audit to understand the existing usages of button elements so we can create a Button component that handles all existing functionality.

The following modules will cover how to transform those existing button elements into Button components, and then how to prevent future usages of button elements.

For the remainder of this course we'll work with the codebase of a small sample app. We can then apply AST-based tooling to refactor it.

Intro to a sample codebase#