Re-implementing Recoil APIs / article gists

core.ts

// @see https://github.com/NoriSte/recoil-apis

/**
 * Provide a Recoil Value setter
 * @private
 */
const coreSetRecoilValue = <T>(
  recoilId: string,
  recoilValue: RecoilValue<T>,
  nextValue: T
) => {
  if (isAtom(recoilValue)) {
    coreSetAtomValue(recoilId, recoilValue, nextValue);
  } else if (recoilValue.set) {
    recoilValue.set(
      {
        get: createPublicGetRecoilValue(recoilId),
        set: createPublicSetRecoilValue(recoilId)
      },
      nextValue
    );
  }
};

/**
 * Set the Recoil Atom and notify the subscribers without passing the recoil id
 */
const coreSetAtomValue = <T>(
  recoilId: string,
  recoilValue: RecoilValue<T>,
  nextValue: T
) => {
  const coreRecoilValue = getRecoilStore(recoilId)[recoilValue.key];

  if (coreRecoilValue.type !== "atom") {
    throw new Error(`${coreRecoilValue.key} is not an atom`);
  }

  if (nextValue !== coreRecoilValue.value) {
    coreRecoilValue.value = nextValue;
    coreRecoilValue.subscribers.forEach((callback) => callback());
  }
};

/**
 * Create a function that provide a Recoil Value setter
 * @private
 */
export const createPublicSetRecoilValue = <T>(recoilId: string) => (
  recoilValue: RecoilValue<T>,
  nextValue: T
) => coreSetRecoilValue(recoilId, recoilValue, nextValue);

/**
 * Create a function that sets the Recoil Atom and notify the subscribers without passing the recoil id
 * @private
 */
export const createPublicSetAtomValue = <T>(
  recoilId: string,
  recoilValue: RecoilValue<T>
) => (nextValue: T) => coreSetAtomValue(recoilId, recoilValue, nextValue);