Shrugsy

export type Entries<T> = {
  [K in keyof T]: [K, T[K]];
}[keyof T][];
  
/**
 * Helper to use `Object.entries` while retaining key type information.
 * Input object should be cast `as const` for maximum effectiveness.
 */
export function objEntries<T extends Record<string, unknown>>(obj: T): Entries<T> {
  return Object.entries(obj) as Entries<T>;

Shrugsy

import { useRef, useCallback} from 'react';

/**
 * Accepts a given callback, and provides a new callback with a stable reference,
 * which will itself always call the latest version of the provided callback.
 * Useful for dealing with third party components that use stale closures.
 * @param callback - the original callback desired to be called
 * @returns A new callback with a stable reference, which when called,
 * calls the latest provided callback
 * @deprecated -  This implementation may have future issues in concurrent mode, as it mutates

Shrugsy

type ComparisonFn = (left: number, right: number) => boolean;

// `buildComparison` is a 'Type Narrowing Identity Function'
// It returns the value given to it, but also narrows the types.
// In this case it allows typescript to retain the literal types of the keys
// rather than widening them to 'string'
const buildComparisons = <Comparison extends Record<string, ComparisonFn>>(comparison: Comparison) => comparison;

// Using the Type Narrowing Identity Function:
const comparisons = buildComparisons({

Shrugsy

Why is my returned JSX not showing?

The problem

You decide you want to show a component on click, so you do this.

function Bar() {
  return <div>This is BAR</div>
}

function Foo() {

Shrugsy

/**
 * Get a union type derived from values of a const asserted array.
 * @example
 * const values = ['foo', 'bar'] as const;
 * type Val = ArrayValues<typeof values>;
 * // => 'foo' | 'bar'
 *
 * See https://github.com/microsoft/TypeScript/issues/28046#issuecomment-607145719
 */
export type ArrayValues<T extends ReadonlyArray<unknown>> = T[number];

Shrugsy

import { FetchBaseQueryError } from '@rtk-incubator/rtk-query/dist';

/**
 * Default tags used by the cacher helpers
 */
const defaultTags = ["UNAUTHORIZED", "UNKNOWN_ERROR"] as const;
type DefaultTags = typeof defaultTags[number];

function concatErrorCache<T, ID>(
  existingCache: CacheList<T, ID>,