Export store's useful typescript definitions - close #5864

[sangxxh]

Close #5864

The store has some internal types that are useful and should be exported to help consumer apps typing their store implementations. See more in #5864

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Tests

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[dreitzner]

Exports "missing" store types. If there are no side effects that are not know to me this should be great.

[dummdidumm]

The same was already proposed in #5170, and @Conduitry said that he doesn't want to expose Invalidator and StartStopNotifier as these are internal API. So we would at least need to remove these two from the exports.

[sangxxh]

The same was already proposed in #5170, and @Conduitry said that he doesn't want to expose Invalidator and StartStopNotifier as these are internal API. So we would at least need to remove these two from the exports.

I have removed the exports for those 2 types.

Also trying to have some careful thought about the other types of the store. On one hand, they're helpful, on the other hand, I can get around the limitation of not exporting them by writing code as such:

/**
 * Instead of:
 * getCoinList: StartStopNotifier<ReadonlyArray<CoinMarketData>> = (
 * 	set: Subscriber<Date>
 * ) => {
 * 	...
 * 
 * 	set(...)
 * }
 *
 * Write like this:
 */
async function getCoinList(): Promise<ReadonlyArray<CoinMarketData>> {
	const res = await fetch(
		'https://api.coingecko.com/api/v3/coins/markets?vs_currency=usd'
	);

	if (!res.ok) {
		throw new Error(await res.text());
	}

	const markets = await res.json();
	return createFormattedCurrencyFields(markets);
}


export const coinMarket: Readable<CoinMarketDataStore> = readable(
	initialValue,
	(set) => {
		(async () => {
			try {
				/**
				 * Don't need to call getCoinList(set) 
				 */
				const markets = await getCoinList();
				set({
					markets,
					error: null,
				});
			} catch (error) {
				set({
					markets: [],
					error,
				});
			}
		})();

		return function stop() {
			// nothing
		};
	}
);

What do you think? Does it look like this is the recommended approach rather than exporting the types or we should still export those types for other use cases?

[dummdidumm]

I gotta reverse my opinion on StartStopNotifier. This one is okay to export, too, it's public API and it's in the docs - you even must provide that parameter to readable, so ..

[the-homeless-god]

@dummdidumm could you tell what blocks this PR? let's rebase it and merge, why we're awaiting from January?