From d14eb08bf0866b31e213687efa83ac8a8c6a7365 Mon Sep 17 00:00:00 2001
From: Yanick Champoux <yanick@babyl.ca>
Date: Tue, 12 Oct 2021 09:42:30 -0400
Subject: [PATCH] splat

---
 package.json                 |   2 +-
 src/Updux.js                 | 210 ++++++++++++++---------
 src/Updux.test.js            |   8 +-
 src/buildInitial/index.js    |   2 +
 src/buildMiddleware/index.js |   2 +-
 src/buildSelectors/index.js  |  23 ++-
 src/buildUpreducer.js        |  16 +-
 src/splat.test.js            | 314 +++++++++++++++++++++++++++++++++++
 src/subscriptions.test.js    |   1 -
 9 files changed, 489 insertions(+), 89 deletions(-)
 create mode 100644 src/splat.test.js

diff --git a/package.json b/package.json
index 0da9286..da95d6b 100644
--- a/package.json
+++ b/package.json
@@ -64,7 +64,7 @@
         "url": "https://github.com/yanick/updux/issues"
     },
     "homepage": "https://github.com/yanick/updux#readme",
-    "types": "./dist/index.d.ts",
+    "types": "./types/index.d.ts",
     "prettier": {
         "tabWidth": 4,
         "singleQuote": true,
diff --git a/src/Updux.js b/src/Updux.js
index 4c1b65f..49d3517 100644
--- a/src/Updux.js
+++ b/src/Updux.js
@@ -1,7 +1,8 @@
+/* TODO change * for leftovers to +, change subscriptions to reactions */
 import moize from 'moize';
 import u from '@yanick/updeep';
 import { createStore as reduxCreateStore, applyMiddleware } from 'redux';
-import { map, mapValues } from 'lodash-es';
+import { get, map, mapValues, merge, difference } from 'lodash-es';
 
 import { buildInitial } from './buildInitial/index.js';
 import { buildActions } from './buildActions/index.js';
@@ -13,56 +14,6 @@ import {
     augmentMiddlewareApi,
 } from './buildMiddleware/index.js';
 
-function _subscribeToStore(store, subscriptions) {
-    for (const sub of subscriptions) {
-        const subscriber = sub({
-            ...store,
-            subscribe(subscriber) {
-                let previous;
-                const unsub = store.subscribe(() => {
-                    const state = store.getState();
-                    if (state === previous) return;
-                    let p = previous;
-                    previous = state;
-                    subscriber(state, p, unsub);
-                });
-            },
-        });
-
-        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, previous, unsub) =>
-        subscription(localStore)(
-            state[slice],
-            previous && previous[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
  * `Updux` is a way to minimize and simplify the boilerplate associated with the
@@ -71,6 +22,7 @@ const memoizeSubscription = (subscription) => (store) => {
  * In true `Redux`-like fashion, upduxes can be made of sub-upduxes (`subduxes` for short) for different slices of the root state.
  */
 export class Updux {
+    /** @type { unknown } */
     #initial = {};
     #subduxes = {};
 
@@ -80,10 +32,19 @@ export class Updux {
     #mutations = {};
     #effects = [];
     #subscriptions = [];
+    #splatSelector = undefined;
+    #splatReaction = undefined;
 
     constructor(config) {
         this.#initial = config.initial ?? {};
         this.#subduxes = config.subduxes ?? {};
+
+        if (config.subduxes) {
+            this.#subduxes = mapValues(config.subduxes, (sub) =>
+                sub instanceof Updux ? sub : new Updux(sub)
+            );
+        }
+
         if (config.actions) {
             for (const [type, actionArg] of Object.entries(config.actions)) {
                 if (typeof actionArg === 'function' && actionArg.type) {
@@ -98,6 +59,8 @@ export class Updux {
 
         this.#mutations = config.mutations ?? {};
 
+        this.#splatSelector = config.splatSelector;
+
         Object.keys(this.#mutations)
             .filter((action) => action !== '*')
             .filter((action) => !this.actions.hasOwnProperty(action))
@@ -110,6 +73,8 @@ export class Updux {
         }
 
         this.#subscriptions = config.subscriptions ?? [];
+
+        this.#splatReaction = config.splatReaction;
     }
 
     #memoInitial = moize(buildInitial);
@@ -122,6 +87,10 @@ export class Updux {
         return this.#subscriptions;
     }
 
+    setSplatSelector(name, f) {
+        this.#splatSelector = [name, f];
+    }
+
     get middleware() {
         return this.#memoMiddleware(
             this.#effects,
@@ -131,6 +100,7 @@ export class Updux {
         );
     }
 
+    /** @return { import('./Updux').What } */
     get initial() {
         return this.#memoInitial(this.#initial, this.#subduxes);
     }
@@ -143,7 +113,11 @@ export class Updux {
     }
 
     get selectors() {
-        return this.#memoSelectors(this.#selectors, this.#subduxes);
+        return this.#memoSelectors(
+            this.#selectors,
+            this.#splatSelector,
+            this.#subduxes
+        );
     }
 
     get upreducer() {
@@ -193,7 +167,49 @@ export class Updux {
         this.#effects = [...this.#effects, [action, effect]];
     }
 
-    subscribeTo(store, subscription) {
+    splatSubscriber(store, inner, splatReaction) {
+        const cache = {};
+
+        return () => (state, previous, unsub) => {
+            const cacheKeys = Object.keys(cache);
+
+            const newKeys = difference(Object.keys(state), cacheKeys);
+
+            for (const slice of newKeys) {
+                let localStore = {
+                    ...store,
+                    getState: () => store.getState()[slice],
+                };
+
+                cache[slice] = [];
+
+                if (typeof splatReaction === 'function') {
+                    localStore = {
+                        ...localStore,
+                        ...splatReaction(localStore, slice),
+                    };
+                }
+
+                const { unsub, subscriber, subscriberRaw } =
+                    inner.subscribeAll(localStore);
+
+                cache[slice].push({ unsub, subscriber, subscriberRaw });
+                subscriber();
+            }
+
+            const deletedKeys = difference(cacheKeys, Object.keys(state));
+
+            for (const deleted of deletedKeys) {
+                for (const inner of cache[deleted]) {
+                    inner.subscriber();
+                    inner.unsub();
+                }
+                delete cache[deleted];
+            }
+        };
+    }
+
+    subscribeTo(store, subscription, setupArgs = []) {
         const localStore = augmentMiddlewareApi(
             {
                 ...store,
@@ -204,37 +220,86 @@ export class Updux {
             this.selectors
         );
 
-        const subscriber = subscription(localStore);
+        const subscriber = subscription(localStore, ...setupArgs);
 
         let previous;
 
-        const unsub = store.subscribe(() => {
+        const memoSub = () => {
             const state = store.getState();
             if (state === previous) return;
             let p = previous;
             previous = state;
             subscriber(state, p, unsub);
-        });
+        };
+
+        let ret = store.subscribe(memoSub);
+        const unsub = typeof ret === 'function' ? ret : ret.unsub;
+        return {
+            unsub,
+            subscriber: memoSub,
+            subscriberRaw: subscriber,
+        };
     }
 
-    createStore() {
+    subscribeAll(store) {
+        let results = this.#subscriptions.map((sub) =>
+            this.subscribeTo(store, sub)
+        );
+
+        for (const subdux in this.#subduxes) {
+            if (subdux !== '*') {
+                const localStore = {
+                    ...store,
+                    getState: () => get(store.getState(), subdux),
+                };
+                results.push(this.#subduxes[subdux].subscribeAll(localStore));
+            }
+        }
+
+        if (this.#splatReaction) {
+            results.push(
+                this.subscribeTo(
+                    store,
+                    this.splatSubscriber(
+                        store,
+                        this.#subduxes['*'],
+                        this.#splatReaction
+                    )
+                )
+            );
+        }
+
+        return {
+            unsub: () => results.forEach(({ unsub }) => unsub()),
+            subscriber: () => results.forEach(({ subscriber }) => subscriber()),
+            subscriberRaw: (...args) =>
+                results.forEach(({ subscriberRaw }) => subscriberRaw(...args)),
+        };
+    }
+
+    createStore(initial) {
         const store = reduxCreateStore(
             this.reducer,
-            this.initial,
+            initial ?? this.initial,
             applyMiddleware(this.middleware)
         );
 
         store.actions = this.actions;
 
-        store.selectors = mapValues(this.selectors, (selector) => {
-            return (...args) => {
-                let result = selector(store.getState());
+        store.selectors = this.selectors;
 
-                if (typeof result === 'function') return result(...args);
+        merge(
+            store.getState,
+            mapValues(this.selectors, (selector) => {
+                return (...args) => {
+                    let result = selector(store.getState());
 
-                return result;
-            };
-        });
+                    if (typeof result === 'function') return result(...args);
+
+                    return result;
+                };
+            })
+        );
 
         for (const action in this.actions) {
             store.dispatch[action] = (...args) => {
@@ -242,18 +307,11 @@ export class Updux {
             };
         }
 
-        this.#subscriptions.forEach((sub) => this.subscribeTo(store, sub));
-
-        for (const subdux in this.#subduxes) {
-            const localStore = {
-                ...store,
-                getState: () => store.getState()[subdux],
-            };
-            for (const subscription of this.#subduxes[subdux].subscriptions) {
-                this.#subduxes[subdux].subscribeTo(localStore, subscription);
-            }
-        }
+        this.subscribeAll(store);
 
         return store;
     }
 }
+
+const x = new Updux();
+x.selectors;
diff --git a/src/Updux.test.js b/src/Updux.test.js
index c2b552a..c8e1126 100644
--- a/src/Updux.test.js
+++ b/src/Updux.test.js
@@ -74,7 +74,7 @@ test('basic selectors', async (t) => {
             getBar: ({ bar }) => bar,
         },
     });
-    dux.addSelector('getFoo', (state) => state.foo);
+    dux.addSelector('getFoo', ({ foo }) => foo);
     dux.addSelector(
         'getAdd',
         ({ foo }) =>
@@ -91,9 +91,9 @@ test('basic selectors', async (t) => {
 
     const store = dux.createStore();
 
-    t.equal(store.selectors.getFoo(), 1);
-    t.equal(store.selectors.getQuux(), 3);
-    t.equal(store.selectors.getAdd(7), 8);
+    t.equal(store.getState.getFoo(), 1);
+    t.equal(store.getState.getQuux(), 3);
+    t.equal(store.getState.getAdd(7), 8);
 });
 
 test('mutations', async (t) => {
diff --git a/src/buildInitial/index.js b/src/buildInitial/index.js
index b387363..9f2b68b 100644
--- a/src/buildInitial/index.js
+++ b/src/buildInitial/index.js
@@ -7,6 +7,8 @@ export function buildInitial(initial, subduxes = {}) {
             "can't have subduxes on a dux which state is not an object"
         );
 
+    if (Object.keys(subduxes).length === 1 && subduxes['*']) return initial;
+
     const subInitial = mapValues(subduxes, ({ initial }, key) =>
         key === '*' ? [] : initial
     );
diff --git a/src/buildMiddleware/index.js b/src/buildMiddleware/index.js
index af4697f..e941244 100644
--- a/src/buildMiddleware/index.js
+++ b/src/buildMiddleware/index.js
@@ -69,7 +69,7 @@ export function buildMiddleware(
     sub = {}
 ) {
     let inner = map(sub, ({ middleware }, slice) =>
-        middleware ? sliceMw(slice, middleware) : undefined
+        slice !== '*' && middleware ? sliceMw(slice, middleware) : undefined
     ).filter((x) => x);
 
     const local = effects.map((effect) =>
diff --git a/src/buildSelectors/index.js b/src/buildSelectors/index.js
index b2bbc62..98c9acd 100644
--- a/src/buildSelectors/index.js
+++ b/src/buildSelectors/index.js
@@ -1,11 +1,30 @@
 import { map, mapValues, merge } from 'lodash-es';
 
-export function buildSelectors(localSelectors, subduxes) {
+export function buildSelectors(localSelectors, splatSelector, subduxes) {
     const subSelectors = map(subduxes, ({ selectors }, slice) => {
         if (!selectors) return {};
+        if (slice === '*') return {};
 
         return mapValues(selectors, (func) => (state) => func(state[slice]));
     });
 
-    return merge({}, ...subSelectors, localSelectors);
+    let splat = {};
+    if (splatSelector) {
+        splat[splatSelector[0]] =
+            (state) =>
+            (...args) => {
+                const value = splatSelector[1](state)(...args);
+
+                const res = () => value;
+                return merge(
+                    res,
+                    mapValues(
+                        subduxes['*'].selectors,
+                        (selector) => () => selector(value)
+                    )
+                );
+            };
+    }
+
+    return merge({}, ...subSelectors, localSelectors, splat);
 }
diff --git a/src/buildUpreducer.js b/src/buildUpreducer.js
index e2b26b3..71ccada 100644
--- a/src/buildUpreducer.js
+++ b/src/buildUpreducer.js
@@ -11,11 +11,19 @@ export function buildUpreducer(initial, mutations, subduxes = {}) {
         let newState = state ?? initial;
 
         if (subReducers) {
-            const update = mapValues(subReducers, (upReducer) =>
-                upReducer(action)
-            );
+            if (subduxes['*']) {
+                newState = u.updateIn(
+                    '*',
+                    subduxes['*'].upreducer(action),
+                    newState
+                );
+            } else {
+                const update = mapValues(subReducers, (upReducer) =>
+                    upReducer(action)
+                );
 
-            newState = u(update, newState);
+                newState = u(update, newState);
+            }
         }
 
         const a = mutations[action.type] || mutations['*'];
diff --git a/src/splat.test.js b/src/splat.test.js
new file mode 100644
index 0000000..1dc7842
--- /dev/null
+++ b/src/splat.test.js
@@ -0,0 +1,314 @@
+import { test } from 'tap';
+import sinon from 'sinon';
+import { difference, omit } from 'lodash-es';
+
+import { Updux } from './Updux.js';
+
+test('initial', async (t) => {
+    const dux = new Updux({
+        initial: {},
+        subduxes: {
+            '*': {
+                initial: { a: 1 },
+            },
+        },
+    });
+
+    t.same(dux.initial, {});
+});
+
+test('actions', async (t) => {
+    const dux = new Updux({
+        initial: {},
+        subduxes: {
+            '*': {
+                initial: { a: 1 },
+                actions: { foo: null },
+            },
+        },
+    });
+
+    t.type(dux.actions.foo, 'function');
+});
+
+test('selectors', async (t) => {
+    const dux = new Updux({
+        initial: {},
+        subduxes: {
+            '*': {
+                initial: { a: 1 },
+                selectors: {
+                    getA: ({ a }) => a,
+                },
+            },
+        },
+    });
+
+    t.same(dux.selectors, {});
+
+    const getInner = (state) => (index) => state[index];
+    dux.setSplatSelector('getInner', getInner);
+
+    t.type(dux.selectors.getInner, 'function');
+
+    t.same(
+        dux.selectors.getInner({
+            one: { a: 1 },
+            two: { a: 2 },
+        })('one')(),
+        { a: 1 }
+    );
+
+    t.same(
+        dux.selectors
+            .getInner({
+                one: { a: 1 },
+                two: { a: 2 },
+            })('one')
+            .getA(),
+        1
+    );
+
+    // and now with the store
+    const store = dux.createStore({
+        one: { a: 1 },
+        two: { a: 2 },
+    });
+
+    t.same(store.getState.getInner('two')(), { a: 2 });
+    t.same(store.getState.getInner('two').getA(), 2);
+});
+
+test('splat middleware', async (t) => {
+    const snitch = sinon.fake(() => true);
+
+    const dux = new Updux({
+        initial: {},
+        subduxes: {
+            '*': {
+                initial: { a: 1 },
+                actions: { foo: null },
+                effects: {
+                    foo: (api) => (next) => (action) => {
+                        snitch();
+                        next(action);
+                    },
+                },
+            },
+        },
+    });
+
+    const store = dux.createStore({ one: { a: 1 }, two: { a: 2 } });
+    store.dispatch.foo();
+
+    t.notOk(snitch.called);
+});
+
+test('splat subscriptions', async (t) => {
+    const snitch = sinon.fake(() => true);
+
+    const dux = new Updux({
+        initial: {},
+        subduxes: {
+            '*': {
+                initial: { a: 1 },
+                actions: { foo: null },
+                mutations: {
+                    foo: (id) => (state) =>
+                        state.a === i ? { ...state, b: 1 } : state,
+                },
+                subscriptions: [
+                    (store) => (state, previous, unsub) => {
+                        snitch(state);
+                    },
+                ],
+            },
+        },
+    });
+
+    const store = dux.createStore({ one: { a: 1 }, two: { a: 2 } });
+    store.dispatch({ type: 'noop' });
+
+    t.notOk(snitch.called);
+});
+
+test('splat subscriptions, more', async (t) => {
+    const snitch = sinon.fake(() => true);
+
+    const inner = new Updux({
+        initial: { a: 1 },
+        actions: { foo: null, incAll: null },
+        mutations: {
+            foo: (id) => (state) => state.a === id ? { ...state, b: 1 } : state,
+            incAll: () => (state) => ({ ...state, a: state.a + 1 }),
+        },
+        subscriptions: [() => snitch],
+    });
+
+    const dux = new Updux({
+        initial: {},
+        actions: {
+            delete: null,
+            newEntry: null,
+        },
+        mutations: {
+            delete: (id) => (state) => omit(state, id),
+            newEntry: (name) => (state) => ({ ...state, [name]: { a: 10 } }),
+        },
+        splatReaction: 'whatev',
+        subduxes: {
+            '*': inner,
+        },
+    });
+
+    const store = dux.createStore({ one: { a: 1 }, two: { a: 2 } });
+    store.dispatch({ type: 'noop' });
+
+    t.equal(snitch.callCount, 2);
+
+    t.same(snitch.firstCall.args[0], { a: 1 });
+    t.same(snitch.secondCall.args[0], { a: 2 });
+
+    snitch.resetHistory();
+
+    store.dispatch.foo(2);
+
+    t.equal(snitch.callCount, 1);
+
+    t.same(snitch.firstCall.args[0], { a: 2, b: 1 });
+
+    snitch.resetHistory();
+    store.dispatch.delete('one');
+
+    t.same(store.getState(), {
+        two: { a: 2, b: 1 },
+    });
+
+    t.equal(snitch.callCount, 1);
+
+    t.ok(
+        snitch.calledWithMatch(
+            undefined,
+            { a: 1 },
+            sinon.match.typeOf('function')
+        )
+    );
+
+    await t.test('only one subscriber left', async (t) => {
+        snitch.resetHistory();
+        store.dispatch.incAll();
+
+        t.equal(snitch.callCount, 1);
+
+        t.ok(
+            snitch.calledWithMatch(
+                { a: 3, b: 1 },
+                { a: 2, b: 1 },
+                sinon.match.typeOf('function')
+            )
+        );
+    });
+
+    await t.test('new entry gets subscribed', async (t) => {
+        snitch.resetHistory();
+        store.dispatch.newEntry('newbie');
+
+        t.equal(snitch.callCount, 1);
+
+        t.ok(
+            snitch.calledWithMatch(
+                { a: 10 },
+                undefined,
+                sinon.match.typeOf('function')
+            )
+        );
+    });
+});
+
+test('many levels down', { only: false }, async (t) => {
+    const snitch = sinon.fake(() => true);
+
+    const dux = new Updux({
+        splatReaction: 'potato',
+        actions: { remove: null },
+        mutations: {
+            remove: () => (state) => ({}),
+        },
+        subduxes: {
+            '*': {
+                subduxes: {
+                    a: {
+                        initial: 1,
+                        actions: {
+                            add: null,
+                        },
+                        mutations: {
+                            add: () => (x) => x + 1,
+                        },
+                        subscriptions: [
+                            (store) => (state) => snitch(state, store),
+                        ],
+                    },
+                },
+            },
+        },
+    });
+
+    const store = dux.createStore({ one: { a: 1 } });
+    store.dispatch({ type: 'foo' });
+
+    t.ok(snitch.calledOnce);
+    t.same(snitch.firstCall.firstArg, 1);
+
+    snitch.resetHistory();
+
+    store.dispatch.remove();
+
+    t.ok(snitch.calledOnce);
+    t.same(snitch.firstCall.firstArg, undefined);
+});
+
+test('inherit info via the store', async (t) => {
+    const snitch = sinon.fake(() => true);
+    const splatSnitch = sinon.fake(() => true);
+
+    const dux = new Updux({
+        splatReaction: (store, key) => {
+            store.itemId = key;
+
+            splatSnitch();
+            return { itemId: key };
+        },
+        subduxes: {
+            '*': {
+                subduxes: {
+                    a: {
+                        initial: 1,
+                        actions: {
+                            add: null,
+                        },
+                        mutations: {
+                            add: () => (x) => x + 1,
+                        },
+                        subscriptions: [
+                            (store) => (state) => snitch(state, store.itemId),
+                        ],
+                    },
+                },
+            },
+        },
+    });
+
+    const store = dux.createStore({
+        one: { a: 1 },
+        two: { a: 2 },
+    });
+
+    store.dispatch({ type: 'noop' });
+
+    t.ok(splatSnitch.calledTwice);
+
+    t.ok(snitch.calledTwice);
+    t.ok(snitch.calledWithMatch(1, 'one'));
+    t.ok(snitch.calledWithMatch(2, 'two'));
+});
diff --git a/src/subscriptions.test.js b/src/subscriptions.test.js
index 6c09023..185fd32 100644
--- a/src/subscriptions.test.js
+++ b/src/subscriptions.test.js
@@ -119,7 +119,6 @@ tap.test('subscription within subduxes', { todo: false }, async (t) => {
         },
         subscriptions: [
             (store) => (state, previous, unsub) => {
-                console.log(state, previous);
                 if (!previous) return;
                 store.subscribe(innerState);
                 unsub();