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How TypeScript Type Predicates Enhance Code Safety

Sachin Chaurasiya on May 18, 2024

TypeScript's type predicates are a powerful feature that improves type safety and makes code more reliable. They help confirm what a variable reall...
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Alexander Opalic •

I think with TypeScript 5.5, you don't need the is syntax anymore.

See devblogs.microsoft.com/typescript/...

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Benny Code •

Doesn't this only apply to arrays?

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Alexander Opalic •

nope luckily not

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Sachin Chaurasiya •

Thanks @alexanderop for sharing this

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Visakh Vijayan •

seems like a lot to type for small an achievement.

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Sachin Chaurasiya •

Yes, but it can save you from a lot of issues

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Benny Code •

True, that's why I would recommend using assertion functions over type predicates.

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Sachin Chaurasiya •

It would be great if you can share some examples, thanks

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Alex Gonzalez •

Incredibly useful! It’s super important to know this type validations to reuse types and avoid code duplication

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Sachin Chaurasiya •

Yeah, thanks for reading @algorodev

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Vu Tung Lam •

In fact if you want to check whether an object matches a type/interface, you could use the TypeBox library, that would make the whole process faster and less error-prone.

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Benny Code •

Schema validation with Zod is another helpful library. Makes your code robust and easy to develop: youtube.com/watch?v=V1HWH6FuTMc

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Sachin Chaurasiya •

Thanks, I will check it out.

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Asela •

Useful article!, Thank you for sharing.

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Sachin Chaurasiya •

Thanks @zaselalk

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redirect.pizza •

it turned out cool