What is a Source Map?

Source Map is a file that maps the compiled, minified, or transpiled JavaScript code back to the original source code (for example, written in TypeScript, CoffeeScript, or modern JavaScript using new features).

This allows developer tools (DevTools) in browsers to display the original source code during debugging, even though the browser has loaded the transformed code.

For example, if you have a file app.min.js and a corresponding app.min.js.map, the browser can show the original app.ts or app.js with the original lines and columns, making it much easier to find and fix errors.

Thus, Source Map improves the debugging experience and understanding of code in production.