type-fest VS proposal-class-fields

Related: https://github.com/sindresorhus/type-fest/blob/main/source/o...

Typescript doesn’t natively provide an Opaque type that we can use to define a string that has already been localized. If the data looks like a string, Typescript will consider it a string. We can however use utility types that simulate opaque types, like the Opaque definition in type-fest:

With these powerful features, you can create dynamic and expressive types. One last thing I want to mention before moving on, is that you can install libraries with which you can add more types to your project like type-fest or utility-types. These libraries contain a lot of useful types that you can use in your project.

Also, it’s not as restrictive as mutability tools — if you know what you are doing and want to ignore this limitation for a particular case, you can apply the -readonly modifier or the Writeable type from type-fest or ts-essentials.

Remember you can derive one type from another type so you can make sure they don't diverge. SetOptional type util

Some folks have built whole SQL databases and DSL compilers in the TS type system. These tend to be toy projects with disclaimers not to use them. But the type system being Turing complete[0] (for better or worse), pretty much whatever you can imagine. This project[1] is one I actually return to frequently for practical ideas.

0: https://github.com/microsoft/TypeScript/issues/14833

1: https://github.com/sindresorhus/type-fest

Have a look at SetRequired and SetOptional in type-fest

Try the Exact method provided by Type Fest, looks like it does what you're looking for

This is a fairly common scenario and available via libraries like type-fest or implementable with a couple lines of code.

Private methods: Pretty simple to explain, private methods and fields straight up do not work with ES6 proxies, its a known issue https://github.com/tc39/proposal-class-fields/issues/106

The #x syntax is ugly and many people don't like it. But if you understand how JavaScript works, you'll see that private x is not possible. Some comments on the proposal suggested private #x and there were plenty of other suggestions as well, it may be interesting to read through those discussions.

> - # private... not sure why they didn't just use the "private" keyword, but I don't care. I almost always use TypeScript anyways

One of the reasons was to allow private and public fields of the same name, so that subclasses are free to add own public fields without accidentally discovering private fields. There were many more considerations that went into the design: https://github.com/tc39/proposal-class-fields/blob/main/PRIV....

There was a heated debate about this and the choice of the # sigil back in 2015 at the time private fields were being designed: https://github.com/tc39/proposal-private-fields/issues/14.

Private class fieldlari va nihoyat classlarda access modifierlarni (private,static) qo'llash imkonini beruvchi sintaksis.

class App extends React.Component { constructor(props) { super(props); this.state = { counter: 0 }; }} but due to Babel's class-field support, I don't use it anymore

I am using ReactJS with Babel and Webpack and using ES6 as well as the proposed class fields for arrow functions. I understand that arrow functions make things more efficient by not recreating the functions each render similar to how binding in the constructor works. However, I am not 100% sure if I am using them correctly. The following is a simplified section of my code in three different files.

Working with constructor and calling super() before we can set state. Although this has been solved with the introduction of class fields in JavaScript, Hooks still provide a simpler API