function getCollections()

in fronts-client/src/actions/Collections.ts [194:265]
61 lines of code
5 McCabe index (conditional complexity)

function getCollections(
	collectionIds: string[],
	returnOnlyUpdatedCollections: boolean = false,
): ThunkResult<Promise<string[]>> {
	return async (dispatch: Dispatch, getState: () => State) => {
		dispatch(collectionActions.fetchStart(collectionIds));
		try {
			const collectionResponses = await fetchCollectionsStrategy(
				getState(),
				collectionIds,
				returnOnlyUpdatedCollections,
			);

			if (!collectionResponses) {
				dispatch(
					collectionActions.fetchError(
						'cannot fetch collections for this route',
					),
				);
				return Promise.resolve([]);
			}

			// TODO: test that this works!
			// find all collections missing in the response and ensure their 'fetch'
			// status is reset
			const missingCollections = difference(
				collectionResponses.map((cr) => cr.id),
				collectionIds,
			);
			const missingActions = missingCollections.map((id) =>
				collectionActions.fetchSuccessIgnore({
					id,
				}),
			);

			let missingCollectionActions: Action[][];
			if (!returnOnlyUpdatedCollections) {
				const missingCollectionIds = collectionIds.filter(
					(id) => !collectionResponses.some((response) => response.id === id),
				);
				missingCollectionActions = missingCollectionIds.map((id) =>
					getCollectionActionForMissingCollection(id, getState),
				);
			} else {
				missingCollectionActions = [];
			}
			const actions = collectionResponses.map((collectionResponse) =>
				getCollectionActions(collectionResponse, getState),
			);

			const actionsToBatch = flatten([
				...actions,
				...missingActions,
				...missingCollectionActions,
			]);

			// this is necessary to ensure lastSuccessfulFetchTimestamp, error etc. are always updated
			// (as we rely on them elsewhere to lock editing if stale/errored)
			const noChangesAction = collectionActions.fetchSuccess([]);

			dispatch(
				actionsToBatch.length > 0
					? batchActions(actionsToBatch)
					: noChangesAction,
			);
			return collectionResponses.map(({ id }) => id);
		} catch (error) {
			dispatch(collectionActions.fetchError(error, collectionIds));
			return [];
		}
	};
}