Utilities

This page lists utility APIs re-exported by the public amos package.

import { arrayEqual, isAmosObject, shallowEqual, toJS, type ValueOrFunc } from 'amos';

Amos Objects

interface AmosObject<T extends string> {
  readonly id: string;
  readonly key: string;
}

function isAmosObject<S extends AmosObject<any>>(obj: any, key: string): obj is S;

Amos objects are tagged objects used for boxes, mutations, selectors, actions, and signals.

isAmosObject checks whether a value is an Amos object with the requested kind, such as box, selector, or action.

Equality

function shallowEqual<T>(a: T, b: T): boolean;
function arrayEqual<T extends ArrayLike<any>>(a: T, b: T): boolean;

shallowEqual compares own enumerable keys and strict property values.

arrayEqual compares length and strict item values.

JSON Conversion

function toJS<T>(v: T): JSONState<T>;

toJS recursively converts arrays, toJSON objects, and plain object properties to JSON-like state.

JSONState<T> is the compile-time JSON representation of T. If T has a toJSON() method, JSONState<T> uses that return type recursively.

Enhancers

type Enhancer<A extends any[], V> = (next: (...args: A) => V) => (...args: A) => V;

An enhancer wraps a factory or function with additional behavior. Amos uses this type for store enhancers and for factory enhancers such as action and selector enhancement.

Common Types

type ID = string | number;
type Unsubscribe = () => void;
type AnyFunc = (...args: any[]) => any;
type ValueOrArray<T> = T | T[];
type ValueOrReadonlyArray<T> = T | readonly T[];
type ValueOrPromise<T> = T | Promise<T>;
type ValueOrFunc<V, A extends any[] = []> = V | ((...args: A) => V);
type ValueOrConstructor<V, A extends any[] = []> = V | (new (...args: A) => V);

Other exported type utilities include IsAny, IsNever, IsNoType, and IsUnknown.