@preact-signals/query/src/utils.ts

A reactive utility for React/Preact that simplifies the handling of data fetching and state management. Powered by Preact Signals, it provides hooks and functions to create reactive resources and manage their state seamlessly.

import { untracked } from "@preact-signals/utils";
import { ExecuteOptionsOnReferenceChangeProp } from "./types.ts";
import {
    ReadonlySignal,
  useComputed,
  useSignal,
  useSignalEffect,
} from "@preact-signals/unified-signals";
import { useCallback, useRef } from "react";

export const EMPTY_OBJECT = {} as const;
export const EMPTY_ARRAY = [] as const;

const wrapHandler: ProxyHandler<Function> = {
  apply(target, thisArg, args) {
    return untracked(() => target.apply(thisArg, args));
  },
};

export const wrapWithUntracked = /** __PURE__ */ <T extends Function>(
  fn: T
): T => new Proxy(fn, wrapHandler) as T;

export const wrapFunctionsInUntracked = /** __PURE__ */ <
  T extends Record<any, any>,
>(
  obj: T
): T => {
  for (const key in obj) {
    if (typeof obj[key] === "function") {
      obj[key] = wrapWithUntracked(obj[key]);
    }
  }
  return obj;
};

const defaultExecuteOptions = true;
export const useRefBasedOptions = <
  T extends ExecuteOptionsOnReferenceChangeProp,
>(
  options: () => T
): ReadonlySignal<T> => {
  const optionsRef = useRef(options);
  optionsRef.current = options;
  const unstableCallbackButReferencesLatest = useCallback(
    () => optionsRef.current(),
    [options]
  );

  const needToChangeOptionOnNextRerender = useRef(true);
  const sig = useSignal(unstableCallbackButReferencesLatest);
  if (needToChangeOptionOnNextRerender.current) {
    sig.value = unstableCallbackButReferencesLatest;
  }

  const computed = useComputed(() => sig.value());
  useSignalEffect(() => {
    needToChangeOptionOnNextRerender.current =
      computed.value.executeOptionsOnReferenceChange ?? defaultExecuteOptions;
  });

  return computed;
};