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What’s new with TypeScript 3.9
TypeScript keeps going at lightning speed. My book about TS 3.x has been released in December and now 3.9 is already out! Phew!
Let’s look at what this new release has in store for us!
Speed!
As stated in the release notes, 3.9 is coming with many performance improvements. The TypeScript team and various contributors have fixed multiple issues around this.
They’ve resolved issues with large unions/intersections/conditional types as well as with mapped types. Check out the release notes for a small list of the related pull requests (unsurprisingly many of those were initiated by Anders himself :p).
Daniel Rosenwasser, the program manager for TypeScript, announces a ~40% reduction in compile times for material-ui, which is a rather large project that was experiencing slow build times. I don’t know about you, but this sounds awesome.
Daniel also mentions that TS 3.9 addresses a problem with file renaming. Previously, it took quite a long time to determine which import statements had to be updated after file rename operations. I’ve witnessed this quite a few times and it was indeed annoying; one less problem to worry about!
Having switched to the beta recently, I can indeed confirm that the compilation times are better now; even though my project is not that big!
