updux/src/initial.ts

27 lines
806 B
TypeScript

import u from '@yanick/updeep-remeda';
import * as R from 'remeda';
type SubduxState<S> = 'initialState' extends keyof S ? S['initialState'] : {};
export type AggregateState<LOCAL, SUBDUXES extends Record<any, any>> = LOCAL &
(keyof SUBDUXES extends never
? {}
: {
[Slice in keyof SUBDUXES]: Slice extends string
? SubduxState<SUBDUXES[Slice]>
: never;
});
export function buildInitial(localInitial, subduxes) {
if (Object.keys(subduxes).length > 0 && typeof localInitial !== 'object') {
throw new Error(
"can't have subduxes when the initialState value is not an object",
);
}
return u(
localInitial,
R.mapValues(subduxes, R.pathOr(['initialState'], {})),
);
}