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TypeScript 4.9 Is A Game Changer
The newest 4.9 TypeScript version is just around the corner, and new features are mind-blowing. You will learn about them from this article.
Types Hodor
The new keyword satisfies is a way to make sure your variable fits into a definition of a type. Comparing to casting, satisfies won’t cast the variable to a specific type.
It is useful in so many scenarios, it will surely become a default way of validating type. For example:
Better type narrowing
Sometimes TypeScript went nuts when we have tried to narrow data for example from an API. Now it is easier because “in” operator recognizes better what we are trying to achieve:
Improved NaN interview experience
Trivia about NaN became so popular, TypeScript developers decided to throw some swords from eager interviewers. As we all know, we shouldn’t compare anything with NaN because NaN is not a number, and really — it is nothing specific at all. Now TypeScript will show an error if you will try to compare to NaN by accident.
The mind-blowing thing about this feature is that TypeScript will actually propose a proper way to fix it! A real game changer:
Ultra-fast file change detection
TypeScript's developers were working for years on a performance improvement that will kick everyone lower backs. Compared to polling that basically checks files once and then, file watching is a game changer. The system will notify TypeScript if a file in a project changed. No need to burst that CPU anymore! With TypeScript 4.9 the file watching mechanism is mature enough to become the default way of watching for changes. It will improve build time!
Are you excited with new TypeScript features? I can’t wait to install it, and try all of these goodies myself. TypeScript is amazing!
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