mirror of
https://github.com/sindresorhus/type-fest.git
synced 2025-12-08 19:25:05 +00:00
681f59b36c
Co-authored-by: Sindre Sorhus <sindresorhus@gmail.com> Co-authored-by: Dimitri Benin <BendingBender@users.noreply.github.com>
109 lines
3.3 KiB
TypeScript
109 lines
3.3 KiB
TypeScript
/// <reference lib="esnext"/>
|
|
|
|
// TODO: This can just be `export type Primitive = not object` when the `not` keyword is out.
|
|
/**
|
|
Matches any [primitive value](https://developer.mozilla.org/en-US/docs/Glossary/Primitive).
|
|
*/
|
|
export type Primitive =
|
|
| null
|
|
| undefined
|
|
| string
|
|
| number
|
|
| boolean
|
|
| symbol
|
|
| bigint;
|
|
|
|
// TODO: Remove the `= unknown` sometime in the future when most users are on TS 3.5 as it's now the default
|
|
/**
|
|
Matches a [`class` constructor](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes).
|
|
*/
|
|
export type Class<T = unknown, Arguments extends any[] = any[]> = new(...arguments_: Arguments) => T;
|
|
|
|
/**
|
|
Matches any [typed array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray), like `Uint8Array` or `Float64Array`.
|
|
*/
|
|
export type TypedArray =
|
|
| Int8Array
|
|
| Uint8Array
|
|
| Uint8ClampedArray
|
|
| Int16Array
|
|
| Uint16Array
|
|
| Int32Array
|
|
| Uint32Array
|
|
| Float32Array
|
|
| Float64Array
|
|
| BigInt64Array
|
|
| BigUint64Array;
|
|
|
|
/**
|
|
Matches a JSON object.
|
|
|
|
This type can be useful to enforce some input to be JSON-compatible or as a super-type to be extended from. Don't use this as a direct return type as the user would have to double-cast it: `jsonObject as unknown as CustomResponse`. Instead, you could extend your CustomResponse type from it to ensure your type only uses JSON-compatible types: `interface CustomResponse extends JsonObject { … }`.
|
|
*/
|
|
export type JsonObject = {[key: string]: JsonValue};
|
|
|
|
/**
|
|
Matches a JSON array.
|
|
*/
|
|
export interface JsonArray extends Array<JsonValue> {}
|
|
|
|
/**
|
|
Matches any valid JSON value.
|
|
*/
|
|
export type JsonValue = string | number | boolean | null | JsonObject | JsonArray;
|
|
|
|
declare global {
|
|
interface SymbolConstructor {
|
|
readonly observable: symbol;
|
|
}
|
|
}
|
|
|
|
/**
|
|
Matches a value that is like an [Observable](https://github.com/tc39/proposal-observable).
|
|
*/
|
|
export interface ObservableLike {
|
|
subscribe(observer: (value: unknown) => void): void;
|
|
[Symbol.observable](): ObservableLike;
|
|
}
|
|
|
|
/**
|
|
Creates an opaque type, which hides its internal details from the public, and can only be created by being used explicitly.
|
|
|
|
The generic type parameter can be anything. It doesn't have to be an object.
|
|
|
|
Read more about opaque types [here](https://codemix.com/opaque-types-in-javascript/).
|
|
|
|
There have been several discussions about adding this feature to TypeScript via the `opaque type` operator, similar to how Flow does it. Unfortunately, nothing has (yet) moved forward:
|
|
1. [](https://github.com/Microsoft/TypeScript/issues/15408)
|
|
2. [](https://github.com/Microsoft/TypeScript/issues/15807)
|
|
|
|
@example
|
|
```
|
|
import {Opaque} from 'type-fest';
|
|
|
|
type AccountNumber = Opaque<number>;
|
|
type AccountBalance = Opaque<number>;
|
|
|
|
function createAccountNumber(): AccountNumber {
|
|
return 2 as AccountNumber;
|
|
}
|
|
|
|
function getMoneyForAccount(accountNumber: AccountNumber): AccountBalance {
|
|
return 4 as AccountBalance;
|
|
}
|
|
|
|
// This will compile successfully:
|
|
getMoneyForAccount(createAccountNumber());
|
|
|
|
// But this won't, because it has to be explicitly passed as an AccountNumber.
|
|
getMoneyForAccount(2);
|
|
|
|
// You can use opaque values like they aren't opaque too, like this:
|
|
const accountNumber = createAccountNumber();
|
|
|
|
// This will compile successfully:
|
|
accountNumber + 2;
|
|
```
|
|
*/
|
|
type Opaque<Type> = Type & {readonly __opaque__: unique symbol};
|