feat: lazy creating reducer (#24)

src/model/defineModel.ts

@@ -25,6 +25,7 @@ import type {
 import { isFunction } from '../utils/isType';
 import { Unsubscribe } from 'redux';
 import { freeze, original, isDraft } from 'immer';
+import { lazyLoad } from './lazyLoad';
 
 export const defineModel = <
   Name extends string,
@@ -103,6 +104,7 @@ export const defineModel = <
 
   const getState = <T extends object>(obj: T): T & GetState<State> => {
     return defineGetter(obj, 'state', () => {
+      lazyLoad(uniqueName);
       const state = modelStore.getState()[uniqueName];
       return depsCollector.active
         ? new ObjectDeps(modelStore, uniqueName).start(state)
@@ -218,15 +220,17 @@ export const defineModel = <
     }
   }
 
-  if (events) {
+  const onLazyLoaded = () => {
+    if (!events) return;
+
     const { onInit, onChange, onDestroy } = events;
     const eventCtx: EventCtx<State> = Object.assign(
       composeGetter({ name: uniqueName }, getState),
       enhancedMethods.external,
       enhancedMethods.internal,
     );
 
-    modelStore.onInitialized().then(() => {
+    {
       const subscriptions: Unsubscribe[] = [];
 
       if (onChange) {
@@ -258,8 +262,8 @@ export const defineModel = <
       }
 
       onInit && onInit.call(eventCtx);
-    });
-  }
+    }
+  };
 
   ModelStore.appendReducer.call(
     modelStore,
@@ -269,6 +273,7 @@ export const defineModel = <
       initialState,
       allowRefresh: !skipRefresh,
     }),
+    onLazyLoaded,
   );
 
   const model: InternalModel<Name, State, Action, Effect, Computed> =

src/model/enhanceAction.ts

@@ -1,6 +1,7 @@
 import type { PreModelAction } from '../actions/model';
 import { modelStore } from '../store/modelStore';
 import { toArgs } from '../utils/toArgs';
+import { lazyLoad } from './lazyLoad';
 import type { ActionCtx } from './types';
 
 export interface EnhancedAction<State extends object> {
@@ -26,6 +27,7 @@ export const enhanceAction = <State extends object>(
   };
 
   const fn: EnhancedAction<State> = function () {
+    lazyLoad(modelName);
     return modelStore.dispatch<PreModelAction<State, any[]>>({
       type: actionType,
       model: modelName,

src/model/lazyLoad.ts

@@ -0,0 +1,5 @@
+import { modelStore, ModelStore } from '../store/modelStore';
+
+export function lazyLoad(modelName: string): void {
+  ModelStore.lazyLoad.call(modelStore, modelName);
+}

src/model/useDefined.ts

@@ -3,6 +3,7 @@ import { DestroyLodingAction, DESTROY_LOADING } from '../actions/loading';
 import { loadingStore } from '../store/loadingStore';
 import { ModelStore, modelStore } from '../store/modelStore';
 import { cloneModel } from './cloneModel';
+import { lazyLoad } from './lazyLoad';
 import { HookModel as HookModel, Model } from './types';
 
 let nameCounter = 0;
@@ -25,7 +26,9 @@ export const useDefined = <
       : useDevName(modelName, initialCount, new Error());
 
   const hookModel = useMemo(() => {
-    return cloneModel(uniqueName, globalModel);
+    const model = cloneModel(uniqueName, globalModel);
+    lazyLoad(uniqueName);
+    return model;
   }, [uniqueName]);
 
   return hookModel as any;

src/model/useModel.ts

@@ -4,6 +4,7 @@ import type { HookModel, Model } from './types';
 import { toArgs } from '../utils/toArgs';
 import { useModelSelector } from '../redux/useSelector';
 import { isFunction, isString } from '../utils/isType';
+import { lazyLoad } from './lazyLoad';
 
 /**
  * hooks新旧数据的对比方式：
@@ -212,7 +213,9 @@ export function useModel(): any {
 
   const reducerNames: string[] = [];
   for (i = 0; i < modelsLength; ++i) {
-    reducerNames.push(models[i]!.name);
+    const modelName = models[i]!.name;
+    lazyLoad(modelName);
+    reducerNames.push(modelName);
   }
 
   return useModelSelector((state: Record<string, object>) => {

src/persist/PersistItem.ts

@@ -1,4 +1,5 @@
 import type { StorageEngine } from '../engines';
+import { lazyLoad } from '../model/lazyLoad';
 import type { InternalModel, Model, ModelPersist } from '../model/types';
 import { isObject, isString } from '../utils/isType';
 import { parseState, stringifyState } from '../utils/serialize';
@@ -96,6 +97,7 @@ export class PersistItem {
     this.key = keyPrefix + key;
 
     models.forEach((model) => {
+      lazyLoad(model.name);
       const {
         decode = defaultDecodeFn,
         maxAge: customMaxAge = maxAge,

src/store/modelStore.ts

@@ -28,7 +28,7 @@ interface CreateStoreOptions {
   persist?: PersistOptions[];
 }
 
-export class ModelStore extends StoreBasic<Record<string, any>> {
+export class ModelStore<T = Record<string, any>> extends StoreBasic<T> {
   public topic: Topic<{
     init: [];
     ready: [];
@@ -38,6 +38,10 @@ export class ModelStore extends StoreBasic<Record<string, any>> {
   protected _isReady: boolean = false;
   protected consumers: Record<string, Reducer> = {};
   protected reducerKeys: string[] = [];
+  protected lazyKeys: Record<
+    string,
+    { consumer: Reducer; onComplete: () => void }
+  > = {};
   /**
    * @protected
    */
@@ -125,12 +129,16 @@ export class ModelStore extends StoreBasic<Record<string, any>> {
     this.topic.publish('unmount');
   }
 
-  onInitialized(): Promise<void> {
+  onInitialized(maybeSync?: () => void): Promise<void> {
     return new Promise((resolve) => {
       if (this._isReady) {
+        maybeSync?.();
         resolve();
       } else {
-        this.topic.subscribeOnce('ready', resolve);
+        this.topic.subscribeOnce('ready', () => {
+          maybeSync?.();
+          resolve();
+        });
       }
     });
   }
@@ -189,11 +197,7 @@ export class ModelStore extends StoreBasic<Record<string, any>> {
     };
   }
 
-  public static appendReducer(
-    this: ModelStore,
-    key: string,
-    consumer: Reducer,
-  ): void {
+  protected appendReducer(key: string, consumer: Reducer) {
     const store = this.origin;
     const consumers = this.consumers;
     const exists = store && consumers.hasOwnProperty(key);
@@ -203,6 +207,27 @@ export class ModelStore extends StoreBasic<Record<string, any>> {
     store && !exists && store.replaceReducer(this.reducer);
   }
 
+  public static appendReducer(
+    this: ModelStore,
+    key: string,
+    consumer: Reducer,
+    onComplete: () => void,
+  ): void {
+    this.lazyKeys[key] = {
+      consumer,
+      onComplete,
+    };
+  }
+
+  public static lazyLoad(this: ModelStore, key: string) {
+    if (this.lazyKeys.hasOwnProperty(key)) {
+      const { consumer, onComplete } = this.lazyKeys[key]!;
+      delete this.lazyKeys[key];
+      this.appendReducer(key, consumer);
+      this.onInitialized(onComplete);
+    }
+  }
+
   public static removeReducer(this: ModelStore, key: string): void {
     const store = this.origin;
     const consumers = this.consumers;

test/lazyLoad.test.ts

@@ -0,0 +1,88 @@
+import { defineModel, store } from '../src';
+import { lazyLoad } from '../src/model/lazyLoad';
+import { ModelStore } from '../src/store/modelStore';
+import { basicModel } from './models/basicModel';
+
+beforeEach(() => {
+  store.init();
+});
+
+afterEach(() => {
+  store.unmount();
+});
+
+test('reducer is not in store by default', () => {
+  expect(store.getState()).not.toHaveProperty(basicModel.name);
+});
+
+test('reducer is in store by access state', () => {
+  basicModel.state;
+  expect(store.getState()).toHaveProperty(basicModel.name);
+});
+
+test('reducer is in store by calling reducers', () => {
+  basicModel.plus(1);
+  expect(store.getState()).toHaveProperty(basicModel.name);
+});
+
+test('reducer is in store by manual calling lazyLoad', () => {
+  lazyLoad(basicModel.name);
+  expect(store.getState()).toHaveProperty(basicModel.name);
+});
+
+test('events are called once reducer is loaded', async () => {
+  const initFn = jest.fn();
+  const changeFn = jest.fn();
+  const unmountFn = jest.fn();
+
+  const model = defineModel('event' + Math.random(), {
+    initialState: {
+      count: 0,
+    },
+    reducers: {
+      change(state) {
+        state.count++;
+      },
+    },
+    events: {
+      onInit: initFn,
+      onChange: changeFn,
+      onDestroy: unmountFn,
+    },
+  });
+
+  await store.onInitialized();
+
+  expect(initFn).toBeCalledTimes(0);
+  expect(changeFn).toBeCalledTimes(0);
+  expect(unmountFn).toBeCalledTimes(0);
+
+  model.state;
+  expect(initFn).toBeCalledTimes(1);
+  expect(changeFn).toBeCalledTimes(0);
+  expect(unmountFn).toBeCalledTimes(0);
+
+  model.change();
+  expect(initFn).toBeCalledTimes(1);
+  expect(changeFn).toBeCalledTimes(1);
+  expect(unmountFn).toBeCalledTimes(0);
+
+  model.change();
+  expect(initFn).toBeCalledTimes(1);
+  expect(changeFn).toBeCalledTimes(2);
+  expect(unmountFn).toBeCalledTimes(0);
+
+  ModelStore.removeReducer.call(store, model.name);
+  expect(initFn).toBeCalledTimes(1);
+  expect(changeFn).toBeCalledTimes(2);
+  expect(unmountFn).toBeCalledTimes(1);
+});
+
+test('never load reducer again since it had been destroyed', () => {
+  lazyLoad(basicModel.name);
+  expect(store.getState()).toHaveProperty(basicModel.name);
+
+  ModelStore.removeReducer.call(store, basicModel.name);
+  lazyLoad(basicModel.name);
+  expect(store.getState()).not.toHaveProperty(basicModel.name);
+});

test/lifecycle.test.ts

@@ -1,4 +1,5 @@
 import { cloneModel, defineModel, engines, store } from '../src';
+import { lazyLoad } from '../src/model/lazyLoad';
 import { PersistSchema } from '../src/persist/PersistItem';
 import { ModelStore } from '../src/store/modelStore';
 
@@ -121,10 +122,8 @@ describe('onChange', () => {
         },
       },
     });
-    model.plus();
-    model.minus();
-    expect(testMessage).toBe('');
 
+    lazyLoad(model.name);
     await store.onInitialized();
 
     expect(testMessage).toBe('onInit-prev-0-next-2-');

test/middleware.test.ts

@@ -1,5 +1,6 @@
 import { defineModel, getLoading, store } from '../src';
 import { DestroyLodingAction, DESTROY_LOADING } from '../src/actions/loading';
+import { lazyLoad } from '../src/model/lazyLoad';
 import { loadingStore } from '../src/store/loadingStore';
 import { basicModel } from './models/basicModel';
 import { complexModel } from './models/complexModel';
@@ -14,6 +15,8 @@ afterEach(() => {
 
 test('dispatch the same state should be intercepted', () => {
   const fn = jest.fn();
+  lazyLoad(basicModel.name);
+  lazyLoad(complexModel.name);
   const unsubscribe = store.subscribe(fn);
 
   expect(fn).toHaveBeenCalledTimes(0);