TypeScript 5.5 makes arrays better!
This episode is about TypeScript 5.5. This update focuses primarily on improved inferred type predicates. The type system can now much better understand, for example, if I remove undefined elements from a list. More convenience for us! Great!
Dear viewers!
Today we're taking a look at the TypeScript 5.5 beta. At first glance, it boasts rather cumbersome feature descriptions. But there's much more to it than that!
And as you may have noticed, we're trying out a different recording setup. Remote recordings, even at Papperlapapp. New Work, so to speak. We like it, what do you think?
TypeScript 5.5:
Two features in particular stand out, both dealing with improved type inference:
Even if you didn't know it: We've all worked with type predicates before. Checking whether an element in a list is undefined is most likely such a type predicate.
And until now, there have been many situations where such a type predicate was not understood by the type system, or only with difficulty. This changes with TypeScript 5.5.
Type-safe access to records has also been improved.
Regular expressions are now parsed by TypeScript, and the compiler offers better support in this area as well. Very handy.
The last major section deals with groundwork for improving the generation of declaration files. We can look forward to improved tooling soon.
If this piques your interest, take a look!
What about you? Which feature interests you? Have you ever encountered a problem where you wished for improved type inference?
Let us know in the comments! We're very curious and look forward to hearing from you!
Don't forget to like, subscribe, and hit the bell icon.
With that said: Nonsense - fun with brackets!
Thanks for watching, enjoy, and we look forward to your feedback!
Stefan and Holger
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Links:
The link to our survey: https://forms.gle/fc53DKCmm8Ytarju5
The TypeScript 5.5 Beta announcement: https://devblogs.microsoft.com/typesc...
The source code for this episode: https://github.com/holgergp/typescrip...
Our episode on Awaited Type: • TypeScript 4.5 - Der neue Awaited Typ im D...
▬ Video Contents ▬▬▬▬▬▬▬▬▬▬
00:00 Intro
00:23 Inferred Type Predicates
09:51 Control Flow Narrowing for Constant Indexed Accesses
11:56 Type Imports in JSDoc
14:59 Regular Expression Syntax Checking
17:47 Isolated declarations
19:09 Conclusion