index.ts

import {type DependencyList, useEffect, useRef} from 'react';
import {type DependenciesComparator} from '../types.js';
import {isBrowser} from '../util/const.js';
import {basicDepsComparator, type EffectCallback, type EffectHook} from '../util/misc.js';

/**
 * Like `useEffect` but uses provided comparator function to validate dependency changes.
 *
 * @param callback Function that will be passed to the underlying effect hook.
 * @param deps Dependency list like the one passed to `useEffect`.
 * @param comparator Function that compares two dependency arrays,
 * and returns `true` if they're equal.
 * @param effectHook Effect hook that will be used to run
 * `callback`. Must match the type signature of `useEffect`, meaning that the `callback` should be
 * placed as the first argument and the dependency list as second.
 * @param effectHookRestArgs Extra arguments that are passed to the `effectHook`
 * after the `callback` and the dependency list.
 */
// eslint-disable-next-line max-params
export function useCustomCompareEffect<
	Callback extends EffectCallback = EffectCallback,
	Deps extends DependencyList = DependencyList,
	HookRestArgs extends any[] = any[],
	R extends HookRestArgs = HookRestArgs,
>(
	callback: Callback,
	deps: Deps,
	comparator: DependenciesComparator<Deps> = basicDepsComparator,
	effectHook: EffectHook<Callback, Deps, HookRestArgs> = useEffect,
	...effectHookRestArgs: R
): void {
	const dependencies = useRef<Deps>();

	// Effects are not run during SSR, therefore, it makes no sense to invoke the comparator
	if (
		dependencies.current === undefined ||
		(isBrowser && !comparator(dependencies.current, deps))
	) {
		dependencies.current = deps;
	}

	effectHook(callback, dependencies.current, ...effectHookRestArgs);
}