react-redux/src/types.ts

Official React bindings for Redux

/* eslint-disable no-unused-vars */
// TODO Ignoring all unused variables for now

import {
  ClassAttributes,
  Component,
  ComponentClass,
  ComponentType,
  StatelessComponent,
  Context,
  NamedExoticComponent,
} from 'react'

import { Action, ActionCreator, AnyAction, Dispatch, Store } from 'redux'

// import hoistNonReactStatics = require('hoist-non-react-statics');
import type { NonReactStatics } from 'hoist-non-react-statics'

export type FixTypeLater = any

export type EqualityFn<T> = (a: T | undefined, b: T | undefined) => boolean

/**
 * This interface can be augmented by users to add default types for the root state when
 * using `react-redux`.
 * Use module augmentation to append your own type definition in a your_custom_type.d.ts file.
 * https://www.typescriptlang.org/docs/handbook/declaration-merging.html#module-augmentation
 */
// tslint:disable-next-line:no-empty-interface
export interface DefaultRootState {}

export type AnyIfEmpty<T extends object> = keyof T extends never ? any : T
export type RootStateOrAny = AnyIfEmpty<DefaultRootState>

// Omit taken from https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-8.html
export type Omit<T, K extends keyof T> = Pick<T, Exclude<keyof T, K>>

export type DistributiveOmit<T, K extends keyof T> = T extends unknown
  ? Omit<T, K>
  : never

export interface DispatchProp<A extends Action = AnyAction> {
  dispatch: Dispatch<A>
}

export type AdvancedComponentDecorator<TProps, TOwnProps> = (
  component: ComponentType<TProps>
) => ComponentType<TOwnProps>

/**
 * A property P will be present if:
 * - it is present in DecorationTargetProps
 *
 * Its value will be dependent on the following conditions
 * - if property P is present in InjectedProps and its definition extends the definition
 *   in DecorationTargetProps, then its definition will be that of DecorationTargetProps[P]
 * - if property P is not present in InjectedProps then its definition will be that of
 *   DecorationTargetProps[P]
 * - if property P is present in InjectedProps but does not extend the
 *   DecorationTargetProps[P] definition, its definition will be that of InjectedProps[P]
 */
export type Matching<InjectedProps, DecorationTargetProps> = {
  [P in keyof DecorationTargetProps]: P extends keyof InjectedProps
    ? InjectedProps[P] extends DecorationTargetProps[P]
      ? DecorationTargetProps[P]
      : InjectedProps[P]
    : DecorationTargetProps[P]
}

/**
 * a property P will be present if :
 * - it is present in both DecorationTargetProps and InjectedProps
 * - InjectedProps[P] can satisfy DecorationTargetProps[P]
 * ie: decorated component can accept more types than decorator is injecting
 *
 * For decoration, inject props or ownProps are all optionally
 * required by the decorated (right hand side) component.
 * But any property required by the decorated component must be satisfied by the injected property.
 */
export type Shared<InjectedProps, DecorationTargetProps> = {
  [P in Extract<
    keyof InjectedProps,
    keyof DecorationTargetProps
  >]?: InjectedProps[P] extends DecorationTargetProps[P]
    ? DecorationTargetProps[P]
    : never
}

// Infers prop type from component C
export type GetProps<C> = C extends ComponentType<infer P>
  ? C extends ComponentClass<P>
    ? ClassAttributes<InstanceType<C>> & P
    : P
  : never

// Applies LibraryManagedAttributes (proper handling of defaultProps
// and propTypes), as well as defines WrappedComponent.
export type ConnectedComponent<
  C extends ComponentType<any>,
  P
> = ComponentType<P> &
  NonReactStatics<C> & {
    WrappedComponent: C
  }

// Injects props and removes them from the prop requirements.
// Will not pass through the injected props if they are passed in during
// render. Also adds new prop requirements from TNeedsProps.
// Uses distributive omit to preserve discriminated unions part of original prop type
export type InferableComponentEnhancerWithProps<TInjectedProps, TNeedsProps> = <
  C extends ComponentType<Matching<TInjectedProps, GetProps<C>>>
>(
  component: C
) => ConnectedComponent<
  C,
  DistributiveOmit<GetProps<C>, keyof Shared<TInjectedProps, GetProps<C>>> &
    TNeedsProps
>

// Injects props and removes them from the prop requirements.
// Will not pass through the injected props if they are passed in during
// render.
export type InferableComponentEnhancer<TInjectedProps> =
  InferableComponentEnhancerWithProps<TInjectedProps, {}>

export type InferThunkActionCreatorType<
  TActionCreator extends (...args: any[]) => any
> = TActionCreator extends (
  ...args: infer TParams
) => (...args: any[]) => infer TReturn
  ? (...args: TParams) => TReturn
  : TActionCreator

export type HandleThunkActionCreator<TActionCreator> = TActionCreator extends (
  ...args: any[]
) => any
  ? InferThunkActionCreatorType<TActionCreator>
  : TActionCreator

// redux-thunk middleware returns thunk's return value from dispatch call
// https://github.com/reduxjs/redux-thunk#composition
export type ResolveThunks<TDispatchProps> = TDispatchProps extends {
  [key: string]: any
}
  ? {
      [C in keyof TDispatchProps]: HandleThunkActionCreator<TDispatchProps[C]>
    }
  : TDispatchProps

// the conditional type is to support TypeScript 3.0, which does not support mapping over tuples and arrays;
// once the typings are updated to at least TypeScript 3.1, a simple mapped type can replace this mess
export type ResolveArrayThunks<TDispatchProps extends ReadonlyArray<any>> =
  TDispatchProps extends [
    infer A1,
    infer A2,
    infer A3,
    infer A4,
    infer A5,
    infer A6,
    infer A7,
    infer A8,
    infer A9
  ]
    ? [
        HandleThunkActionCreator<A1>,
        HandleThunkActionCreator<A2>,
        HandleThunkActionCreator<A3>,
        HandleThunkActionCreator<A4>,
        HandleThunkActionCreator<A5>,
        HandleThunkActionCreator<A6>,
        HandleThunkActionCreator<A7>,
        HandleThunkActionCreator<A8>,
        HandleThunkActionCreator<A9>
      ]
    : TDispatchProps extends [
        infer A1,
        infer A2,
        infer A3,
        infer A4,
        infer A5,
        infer A6,
        infer A7,
        infer A8
      ]
    ? [
        HandleThunkActionCreator<A1>,
        HandleThunkActionCreator<A2>,
        HandleThunkActionCreator<A3>,
        HandleThunkActionCreator<A4>,
        HandleThunkActionCreator<A5>,
        HandleThunkActionCreator<A6>,
        HandleThunkActionCreator<A7>,
        HandleThunkActionCreator<A8>
      ]
    : TDispatchProps extends [
        infer A1,
        infer A2,
        infer A3,
        infer A4,
        infer A5,
        infer A6,
        infer A7
      ]
    ? [
        HandleThunkActionCreator<A1>,
        HandleThunkActionCreator<A2>,
        HandleThunkActionCreator<A3>,
        HandleThunkActionCreator<A4>,
        HandleThunkActionCreator<A5>,
        HandleThunkActionCreator<A6>,
        HandleThunkActionCreator<A7>
      ]
    : TDispatchProps extends [
        infer A1,
        infer A2,
        infer A3,
        infer A4,
        infer A5,
        infer A6
      ]
    ? [
        HandleThunkActionCreator<A1>,
        HandleThunkActionCreator<A2>,
        HandleThunkActionCreator<A3>,
        HandleThunkActionCreator<A4>,
        HandleThunkActionCreator<A5>,
        HandleThunkActionCreator<A6>
      ]
    : TDispatchProps extends [infer A1, infer A2, infer A3, infer A4, infer A5]
    ? [
        HandleThunkActionCreator<A1>,
        HandleThunkActionCreator<A2>,
        HandleThunkActionCreator<A3>,
        HandleThunkActionCreator<A4>,
        HandleThunkActionCreator<A5>
      ]
    : TDispatchProps extends [infer A1, infer A2, infer A3, infer A4]
    ? [
        HandleThunkActionCreator<A1>,
        HandleThunkActionCreator<A2>,
        HandleThunkActionCreator<A3>,
        HandleThunkActionCreator<A4>
      ]
    : TDispatchProps extends [infer A1, infer A2, infer A3]
    ? [
        HandleThunkActionCreator<A1>,
        HandleThunkActionCreator<A2>,
        HandleThunkActionCreator<A3>
      ]
    : TDispatchProps extends [infer A1, infer A2]
    ? [HandleThunkActionCreator<A1>, HandleThunkActionCreator<A2>]
    : TDispatchProps extends [infer A1]
    ? [HandleThunkActionCreator<A1>]
    : TDispatchProps extends Array<infer A>
    ? Array<HandleThunkActionCreator<A>>
    : TDispatchProps extends ReadonlyArray<infer A>
    ? ReadonlyArray<HandleThunkActionCreator<A>>
    : never

/**
 * This interface allows you to easily create a hook that is properly typed for your
 * store's root state.
 *
 * @example
 *
 * interface RootState {
 *   property: string;
 * }
 *
 * const useTypedSelector: TypedUseSelectorHook<RootState> = useSelector;
 */
export interface TypedUseSelectorHook<TState> {
  <TSelected>(
    selector: (state: TState) => TSelected,
    equalityFn?: EqualityFn<TSelected>
  ): TSelected
}