add subscriptions

src/Updux.js

@@ -1,14 +1,50 @@
 import moize from 'moize';
 import u from '@yanick/updeep';
 import { createStore as reduxCreateStore, applyMiddleware } from 'redux';
-import { mapValues } from 'lodash-es';
+import { map, mapValues } from 'lodash-es';
 
 import { buildInitial } from './buildInitial/index.js';
 import { buildActions } from './buildActions/index.js';
 import { buildSelectors } from './buildSelectors/index.js';
 import { action } from './actions.js';
 import { buildUpreducer } from './buildUpreducer.js';
-import { buildMiddleware } from './buildMiddleware/index.js';
+import {
+    buildMiddleware,
+    augmentMiddlewareApi,
+} from './buildMiddleware/index.js';
+
+function _subscribeToStore(store, subscriptions) {
+    for (const sub of subscriptions) {
+        const subscriber = sub(store);
+
+        let unsub = store.subscribe(() => subscriber(store.getState(), unsub));
+    }
+}
+
+const sliceSubscriber = (slice, subdux) => (subscription) => (store) => {
+    let localStore = augmentMiddlewareApi(
+        {
+            ...store,
+            getState: () => store.getState()[slice],
+        },
+        subdux.actions,
+        subdux.selectors
+    );
+
+    return (state, unsub) => subscription(localStore)(state[slice], unsub);
+};
+
+const memoizeSubscription = (subscription) => (store) => {
+    let previous = undefined;
+    const subscriber = subscription(store);
+
+    return (state, unsub) => {
+        if (state === previous) return;
+        let p = previous;
+        previous = state;
+        subscriber(state, p, unsub);
+    };
+};
 
 /**
  *  @public
@@ -26,6 +62,7 @@ export class Updux {
     #selectors = {};
     #mutations = {};
     #effects = [];
+    #subscriptions = [];
 
     constructor(config) {
         this.#initial = config.initial ?? {};
@@ -45,6 +82,8 @@ export class Updux {
         if (config.effects) {
             this.#effects = Object.entries(config.effects);
         }
+
+        this.#subscriptions = config.subscriptions ?? [];
     }
 
     #memoInitial = moize(buildInitial);
@@ -53,6 +92,19 @@ export class Updux {
     #memoUpreducer = moize(buildUpreducer);
     #memoMiddleware = moize(buildMiddleware);
 
+    get subscriptions() {
+        const subscriptions = [...this.#subscriptions].map((s) =>
+            memoizeSubscription(s)
+        );
+
+        return [
+            ...subscriptions,
+            ...map(this.#subduxes, (v, k) =>
+                v.subscriptions.map(sliceSubscriber(k, v))
+            ).flat(),
+        ];
+    }
+
     get middleware() {
         return this.#memoMiddleware(
             this.#effects,
@@ -89,6 +141,10 @@ export class Updux {
         return (state, action) => this.upreducer(action)(state);
     }
 
+    addSubscription(subscription) {
+        this.#subscriptions = [...this.#subscriptions, subscription];
+    }
+
     addAction(type, payloadFunc) {
         const theAction = action(type, payloadFunc);
 
@@ -145,6 +201,8 @@ export class Updux {
             };
         }
 
+        _subscribeToStore(store, this.subscriptions);
+
         return store;
     }
 }

src/buildMiddleware/index.js

@@ -13,7 +13,7 @@ const sliceMw = (slice, mw) => (api) => {
     return mw({ ...api, getState: getSliceState });
 };
 
-function augmentMiddlewareApi(api, actions, selectors) {
+export function augmentMiddlewareApi(api, actions, selectors) {
     const getState = () => api.getState();
     const dispatch = (action) => api.dispatch(action);
 

src/subscriptions.test.js

@@ -1,9 +1,10 @@
 import tap from 'tap';
-import Updux from '.';
 import u from '@yanick/updeep';
 
-tap.test( 'subscriptions', async() => {
+import { Updux } from './Updux.js';
+import { action } from './actions.js';
 
+tap.test('subscriptions', async () => {
     const inc = action('inc');
     const set_copy = action('set_copy');
 
@@ -14,14 +15,15 @@ const dux = new Updux({
         },
         actions: {
             inc,
+            set_copy,
         },
         mutations: {
-        inc: payload => u({ x: x => x + 1 }),
-        set_copy: copy => u({ copy }),
+            inc: (payload) => u({ x: (x) => x + 1 }),
+            set_copy: (copy) => u({ copy }),
         },
     });
 
-dux.addSubscription(store => (state, unsubscribe) => {
+    dux.addSubscription((store) => (state, previous, unsubscribe) => {
         if (state.x > 2) return unsubscribe();
 
         store.dispatch(set_copy(state.x));
@@ -37,25 +39,22 @@ store.dispatch(inc());
     store.dispatch(inc());
 
     tap.same(store.getState(), { x: 3, copy: 2 }, 'we unsubscribed');
-
-
 });
 
-tap.test('subduxes subscriptions', async t => {
+tap.test('subduxes subscriptions', async (t) => {
     const inc_top = action('inc_top');
     const inc_bar = action('inc_bar');
     const transform_bar = action('transform_bar');
 
     const bar = new Updux({
         initial: 'a',
-        mutations: [
-            [inc_bar, () => state => state + 'a'],
-            [transform_bar, outcome => () => outcome],
-        ],
+        actions: { inc_bar, transform_bar },
+        mutations: {
+            inc_bar: () => (state) => state + 'a',
+            transform_bar: (outcome) => () => outcome,
+        },
         subscriptions: [
-            store => (state, unsubscribe) => {
-                console.log({ state });
-
+            (store) => (state, previous, unsubscribe) => {
                 if (state.length <= 2) return;
                 unsubscribe();
                 store.dispatch(transform_bar('look at ' + state));
@@ -67,27 +66,24 @@ tap.test('subduxes subscriptions', async t => {
         initial: {
             count: 0,
         },
-        subduxes: {
-            bar: bar.asDux,
+        subduxes: { bar },
+        actions: {
+            inc_top,
         },
-        mutations: [[inc_top, () => u({ count: count => count + 1 })]],
-        effects: [
-            [
-                '*',
-                () => next => action => {
-                    console.log('before ', action.type);
+        mutations: {
+            inc_top: () => u({ count: (count) => count + 1 }),
+        },
+        effects: {
+            '*': () => (next) => (action) => {
                 next(action);
-                    console.log({ action });
             },
-            ],
-        ],
+        },
         subscriptions: [
-            store => {
-                let previous;
-                return ({ count }) => {
+            (store) => {
+                return ({ count }, { count: previous } = {}) => {
                     if (count !== previous) {
                         previous = count;
-                        store.dispatch(inc_bar());
+                        store.dispatch.inc_bar();
                     }
                 };
             },