selector test is passing

src/Updux.ts

@@ -12,7 +12,7 @@ import {
     ActionCreatorWithoutPayload,
     ActionCreatorWithPreparedPayload,
 } from '@reduxjs/toolkit';
-import { AggregateActions, Dux } from './types.js';
+import { AggregateActions, AggregateSelectors, Dux } from './types.js';
 import { buildActions } from './buildActions.js';
 import { buildInitial, AggregateState } from './initial.js';
 import { buildReducer, MutationCase } from './reducer.js';
@@ -51,8 +51,6 @@ export type Mutation<A extends Action<any> = Action<any>, S = any> = (
     action: A,
 ) => (state: S) => S | void;
 
-export type AggregateSelectors<S> = S;
-
 type SelectorForState<S> = (state: S) => unknown;
 type SelectorsForState<S> = {
     [key: string]: SelectorForState<S>;
@@ -84,8 +82,7 @@ export default class Updux<
         string,
         (state: AggregateState<T_LocalState, T_Subduxes>) => any
     >;
-
-    #selectors: AggregateSelectors<T_LocalSelectors>;
+    #selectors: any;
 
     constructor(
         config: Partial<{
@@ -104,6 +101,16 @@ export default class Updux<
 
         this.#initial = buildInitial(this.#localInitial, this.#subduxes);
         this.#localSelectors = config.selectors;
+
+        const basedSelectors = R.mergeAll(
+            Object.entries(this.#subduxes)
+                .filter(([slice, { selectors }]) => selectors)
+                .map(([slice, { selectors }]) =>
+                    R.mapValues(selectors, (s) => (state) => s(state[slice])),
+                ),
+        );
+
+        this.#selectors = R.merge(basedSelectors, this.#localSelectors);
     }
 
     get actions() {
@@ -129,8 +136,12 @@ export default class Updux<
         return store;
     }
 
-    get selectors(): T_LocalSelectors {
-        return this.#localSelectors as any;
+    get selectors(): AggregateSelectors<
+        T_LocalSelectors,
+        T_Subduxes,
+        AggregateState<T_LocalState, T_Subduxes>
+    > {
+        return this.#selectors as any;
     }
 
     // TODO memoize this sucker

src/selectors.test.ts

@@ -22,6 +22,11 @@ test('basic selectors', () => {
         },
     });
 
-    expect(foo.selectors.getY({ bar: { y: 3 } } as typeof foo.initial)).toBe(3);
-    expect(foo.selectors.getX({ x: 4 } as typeof foo.initial)).toBe(4);
+    const sample = {
+        x: 4,
+        bar: { y: 3 },
+    };
+
+    expect(foo.selectors.getY(sample)).toBe(3);
+    expect(foo.selectors.getX(sample)).toBe(4);
 });

src/types.ts

@@ -6,6 +6,7 @@ export type Dux<
 > = Partial<{
     initial: STATE;
     actions: ACTIONS;
+    selectors: Record<string, (state: STATE) => any>;
     reducer: (
         state: STATE,
         action: ReturnType<ACTIONS[keyof ACTIONS]>,
@@ -13,11 +14,25 @@ export type Dux<
 }>;
 
 type ActionsOf<DUX> = DUX extends { actions: infer A } ? A : {};
+type SelectorsOf<DUX> = DUX extends { selectors: infer A } ? A : {};
 
 export type AggregateActions<A, S> = UnionToIntersection<
     ActionsOf<S[keyof S]> | A
 >;
 
+type BaseSelector<F extends (...args: any) => any, STATE> = (
+    state: STATE,
+) => ReturnType<F>;
+
+type BaseSelectors<S, STATE> = {
+    [key in keyof S]: BaseSelector<S[key], STATE>;
+};
+
+export type AggregateSelectors<S, SUBS, STATE = {}> = BaseSelectors<
+    UnionToIntersection<SelectorsOf<SUBS[keyof SUBS]> | S>,
+    STATE
+>;
+
 export type UnionToIntersection<U> = (
     U extends any ? (k: U) => void : never
 ) extends (k: infer I) => void