Generic Types Library

Welcome to the Generic Types library! This library provides a set of generic types designed to help you work with TypeScript efficiently. Below you'll find a list of exported types, their purposes, and usage examples.

Exported Types

ArrayElement

Purpose: Extracts the type of elements within an array type. This is useful when you need to work with the individual elements of an array and want to ensure type safety.

Usage Example:

type NumberArray = number[];
type NumberElement = ArrayElement<NumberArray>; // number

const element: NumberElement = 3; // Valid assignment

Awaited

Purpose: Unwraps the type of a promise to get the resolved value type. This is useful when working with asynchronous functions to ensure type safety for the resolved values.

Usage Example:

type PromiseNumber = Promise<number>;
type ResolvedNumber = Awaited<PromiseNumber>; // number

async function getNumber(): PromiseNumber {
  return 42;
}

const number: ResolvedNumber = await getNumber(); // Valid assignment

UnionToIntersection

Purpose: Converts a union type into an intersection type. This is useful when you want to merge multiple types into a single type with all the properties of the original types.

Usage Example:

type A = { a: string };
type B = { b: number };
type C = { c: boolean };

type ABC = UnionToIntersection<A | B | C>; // { a: string } & { b: number } & { c: boolean }

const example: ABC = {
  a: "Hello",
  b: 42,
  c: true
};

Mutable

Purpose: Makes all properties of a given type mutable. This is useful when you need to modify properties of an object that are otherwise read-only.

Usage Example:

type ReadonlyObject = {
  readonly name: string;
  readonly age: number;
};

type MutableObject = Mutable<ReadonlyObject>;

let person: MutableObject = {
  name: "Alice",
  age: 30
};

person.name = "Bob"; // This is allowed because the properties are now mutable.

MutableKeys

Purpose: Extracts the keys of a type that are mutable. This can be used to determine which properties of an object can be modified.

Usage Example:

type Sample = {
  readonly id: number;
  name: string;
  age: number;
};

type MutableKeysOfSample = MutableKeys<Sample>; // "name" | "age"

const mutableKeys: MutableKeysOfSample = "name"; // Valid assignment

ReadonlyKeys

Purpose: Extracts the keys of a type that are read-only. This is useful for identifying properties that cannot be modified.

Usage Example:

type Sample = {
  readonly id: number;
  name: string;
  age: number;
};

type ReadonlyKeysOfSample = ReadonlyKeys<Sample>; // "id"

const readonlyKeys: ReadonlyKeysOfSample = "id"; // Valid assignment

Installation

To use this library, install it via npm:

npm install @bestcodetools/generic-types

Contributing

Contributions are welcome! Please open an issue or submit a pull request.

License

This project is licensed under ISC License.

Enjoy using the Generic Types library!