Episode 384: Boris Cherny on TypeScript.mp3

Compatibility

TypeScript's compatibility with JavaScript is a significant advantage for developers working with mixed codebases. Boris Cherny explains that TypeScript was designed to support the common practice of using both first-party and third-party JavaScript packages, which often include TypeScript code. This interoperability allows developers to benefit from type checking and auto-completion features without needing to rewrite existing JavaScript code.

The way TypeScript works is you can use JavaScript from TypeScript, and by default when you import a JavaScript module in TypeScript, it's any.

--- Boris Cherny

Marcus Blankenship highlights that this seamless integration is crucial for maintaining flexibility and functionality in modern JavaScript programs 1 2.

   

Migration

Migrating from JavaScript to TypeScript can be a gradual process, allowing teams to adopt TypeScript's benefits without disrupting existing workflows. Boris Cherny describes a common strategy where developers start by renaming JavaScript files with a TS extension, enabling them to opt into TypeScript's strong safety guarantees incrementally. This approach is particularly useful for large codebases, as it allows for a smooth transition while maintaining compatibility with JavaScript.

You might even start with JavaScript code and then gradually migrate the code base to TypeScript.

--- Boris Cherny

Marcus Blankenship notes that TypeScript's design, originating from Microsoft, incorporates familiar syntax for developers experienced with languages like C#, easing the learning curve 3 4.