Speedier TypeScript Compilations with skipLibCheck

Hello, fellow coders! TypeScript has significantly shaped the way we write and think about JavaScript. It offers a sturdy safety harness with its strong type-checking system, but sometimes that safety comes at the expense of compilation speed. Fortunately, TypeScript’s tsconfig has got a neat trick up its sleeve that might just make your compile step fly.

What’s this skipLibCheck?

It’s always a good day when you can make a single config change and see a performance improvement. So, let’s unravel what skipLibCheck in tsconfig is all about.

In tsconfig.json, nestled within compilerOptions, you’ll find the option for skipLibCheck.

{
  "compilerOptions": {
    "skipLibCheck": true
  }
}

How does it work?

By default, TypeScript is diligent. It checks every nook and cranny of your codebase, ensuring type safety. This includes diving deep into your imported libraries and checking their types as well.

When you set skipLibCheck to true, you’re essentially asking TypeScript to take a chill pill when it comes to libraries. It will skip the type checking for the declaration files (*.d.ts) of your imported libraries.

And the reward for this? A potentially significant boost in compilation speed.

Advantages

1. Faster Compilation: For large projects with numerous imported libraries, not checking every library can drastically reduce compile time.
2. Less Noise: Sometimes, third-party libraries may have types that cause issues or conflicts. By skipping library checks, you bypass those potential error messages.

Trade-offs to Consider

1. Potential Type Errors: While skipping library checks can speed things up, you might miss out on some type-checking that could catch issues related to third-party libraries.
2. Dependency on Accurate Types: You’re relying on the accuracy of the library’s types. If there’s an error in their type definitions, you might not catch it.

When to Use skipLibCheck?

Deciding to use skipLibCheck really boils down to a balance between performance and safety:

• Turn it On When:

  • Your project heavily relies on numerous third-party libraries, and compile speed is essential.
  • You trust the type definitions of your imported libraries or are willing to manage potential type issues manually.

• Exercise Caution or Avoid When:

  • Type accuracy across your entire project, including libraries, is crucial.
  • You’re working in a setting where type issues from third-party libraries have caused problems in the past.

Parting Thoughts

Configurations like skipLibCheck highlight the flexibility and customization TypeScript offers. While such tweaks can provide immediate performance benefits, always weigh the pros and cons for your specific use case.

Always curious, always coding. Until our next tech deep dive, stay sharp and keep optimizing! 🚀🖖

Written by Zubin Khavarian