typedux
Version:
Slightly adjusted Redux (awesome by default) for TS
84 lines (83 loc) • 3.16 kB
TypeScript
import { State } from "../reducers";
/**
* Copyright (C) 2019-present, Rimeto, LLC.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
/**
* A generic type that cannot be `undefined`.
*/
declare type Defined<T> = Exclude<T, undefined>;
/**
* `SelectorChainObjectWrapper` gives TypeScript visibility into the properties of
* an `SelectorChainType` object at compile-time.
*/
declare type SelectorChainObjectWrapper<S extends State<string>, T> = {
[K in keyof T]-?: SelectorChainType<S, T[K]>;
};
/**
* Data accessor interface to dereference the value of the `TSOCType`.
*/
export interface SelectorChainDataAccessor<S extends State<string>, T> {
/**
* Data accessor without a default value. If no data exists,
* `undefined` is returned.
*/
(noDefaultValue?: undefined): Defined<T> | undefined;
/**
* Data accessor with default value.
*/
(defaultValue: NonNullable<T>): NonNullable<T>;
(nullDefaultValue: T extends null ? null : never): Defined<T>;
}
/**
* `SelectorChainArrayWrapper` gives TypeScript visibility into the `SelectorChainType` values of an array
* without exposing Array methods (it is problematic to attempt to invoke methods during
* the course of an optional chain traversal).
*/
export interface SelectorChainArrayWrapper<S extends State<string>, T> {
length: SelectorChainType<S, number>;
[K: number]: SelectorChainType<S, T>;
}
/**
* Data accessor interface to dereference the value of an `any` type.
* @extends SelectorChainDataAccessor<any>
*/
export interface SelectorChainAny extends SelectorChainDataAccessor<any, any> {
[K: string]: SelectorChainAny;
}
/**
* `SelectorChainDataWrapper` selects between `SelectorChainArrayWrapper`, `SelectorChainObjectWrapper`, and `SelectorChainDataAccessor`
* to wrap Arrays, Objects and all other types respectively.
*/
export declare type SelectorChainDataWrapper<S extends State<string>, T> = 0 extends (1 & T) ? SelectorChainAny : T extends any[] ? SelectorChainArrayWrapper<S, T[number]> : T extends object ? SelectorChainObjectWrapper<S, T> : SelectorChainDataAccessor<S, T>;
/**
* An object that supports optional chaining
*/
export declare type SelectorChainType<S extends State<string>, T> = SelectorChainDataAccessor<S, T> & SelectorChainDataWrapper<S, NonNullable<T>>;
/**
* Optional chaining with default values. To inspect a property value in
* a tree-like structure, invoke it as a function, optionally passing a default value.
*
* @example
* // Given:
* const x = oc<T>({
* a: 'hello',
* b: { d: 'world' },
* c: [-100, 200, -300],
* });
*
* // Then:
* x.a() === 'hello'
* x.b.d() === 'world'
* x.c[0]() === -100
* x.c[100]() === undefined
* x.c[100](1234) === 1234
* x.c.map((e) => e()) === [-100, 200, -300]
* x.d.e() === undefined
* x.d.e('optional default value') === 'optional default value'
* (x as any).y.z.a.b.c.d.e.f.g.h.i.j.k() === undefined
*/
export declare function selector<S extends State<string>, T>(data?: T): SelectorChainType<S, T>;
export {};