Skip to content

Add first version of types for useSelector hook #1753

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jul 6, 2021
Merged

Add first version of types for useSelector hook #1753

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
41 changes: 24 additions & 17 deletions src/hooks/useSelector.js → src/hooks/useSelector.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,29 +3,35 @@ import { useReduxContext as useDefaultReduxContext } from './useReduxContext'
import Subscription from '../utils/Subscription'
import { useIsomorphicLayoutEffect } from '../utils/useIsomorphicLayoutEffect'
import { ReactReduxContext } from '../components/Context'
import { AnyAction, Store } from 'redux'
import { DefaultRootState } from '../types'

const refEquality = (a, b) => a === b
type EqualityFn<T> = (a: T | undefined, b: T | undefined) => boolean;

function useSelectorWithStoreAndSubscription(
selector,
equalityFn,
store,
contextSub
) {
const refEquality: EqualityFn<any> = (a, b) => a === b

type TSelector<S, R> = (state: S) => R;

function useSelectorWithStoreAndSubscription<TStoreState, TSelectedState>(
selector: TSelector<TStoreState, TSelectedState>,
equalityFn: EqualityFn<TSelectedState>,
store: Store<TStoreState, AnyAction>,
contextSub: Subscription
): TSelectedState {
const [, forceRender] = useReducer((s) => s + 1, 0)

const subscription = useMemo(() => new Subscription(store, contextSub), [
store,
contextSub,
])

const latestSubscriptionCallbackError = useRef()
const latestSelector = useRef()
const latestStoreState = useRef()
const latestSelectedState = useRef()
const latestSubscriptionCallbackError = useRef<Error>()
const latestSelector = useRef<TSelector<TStoreState, TSelectedState>>()
const latestStoreState = useRef<TStoreState>()
const latestSelectedState = useRef<TSelectedState>()

const storeState = store.getState()
let selectedState
let selectedState: TSelectedState | undefined

try {
if (
Expand Down Expand Up @@ -65,7 +71,7 @@ function useSelectorWithStoreAndSubscription(
function checkForUpdates() {
try {
const newStoreState = store.getState()
const newSelectedState = latestSelector.current(newStoreState)
const newSelectedState = latestSelector.current!(newStoreState)

if (equalityFn(newSelectedState, latestSelectedState.current)) {
return
Expand All @@ -92,7 +98,7 @@ function useSelectorWithStoreAndSubscription(
return () => subscription.tryUnsubscribe()
}, [store, subscription])

return selectedState
return selectedState!
}

/**
Expand All @@ -101,12 +107,13 @@ function useSelectorWithStoreAndSubscription(
* @param {React.Context} [context=ReactReduxContext] Context passed to your `<Provider>`.
* @returns {Function} A `useSelector` hook bound to the specified context.
*/
export function createSelectorHook(context = ReactReduxContext) {
export function createSelectorHook(context = ReactReduxContext): <TState = DefaultRootState, Selected = unknown>(selector: (state: TState) => Selected, equalityFn?: EqualityFn<Selected>) => Selected {
const useReduxContext =
context === ReactReduxContext
? useDefaultReduxContext
: () => useContext(context)
return function useSelector(selector, equalityFn = refEquality) {

return function useSelector<TState, Selected extends unknown>(selector: (state: TState) => Selected, equalityFn: EqualityFn<Selected> = refEquality): Selected {
if (process.env.NODE_ENV !== 'production') {
if (!selector) {
throw new Error(`You must pass a selector to useSelector`)
Expand All @@ -120,7 +127,7 @@ export function createSelectorHook(context = ReactReduxContext) {
)
}
}
const { store, subscription: contextSub } = useReduxContext()
const { store, subscription: contextSub } = useReduxContext()!

const selectedState = useSelectorWithStoreAndSubscription(
selector,
Expand Down