From: Eduardo San Martin Morote <posva13@gmail.com>
Date: Tue, 14 Jan 2020 17:35:29 +0000 (+0100)
Subject: refactor: use a WeakMap for stores to support SSR
X-Git-Tag: 0.0.5~23
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b9a4c29195c1f61a6b6fd3f40247432b9f05ee41;p=thirdparty%2Fvuejs%2Fpinia.git

refactor: use a WeakMap for stores to support SSR
---

diff --git a/__tests__/store.patch.spec.ts b/__tests__/store.patch.spec.ts
index d8e74a64..3c181a42 100644
--- a/__tests__/store.patch.spec.ts
+++ b/__tests__/store.patch.spec.ts
@@ -1,15 +1,17 @@
-import { createStore } from '../src'
+import { createStore, setActiveReq } from '../src'
 
 describe('store.patch', () => {
-  const useStore = createStore('main', () => ({
-    // TODO: the boolean cas shouldn't be necessary
-    // https://www.typescriptlang.org/play/#code/MYewdgzgLgBCMF4YG8CwAoGWYEMBcMUATgK4CmGAvhhiAHQ6IwBmOANhBehqJLMETI4oZJgAoAlIgB8MMclwFi5GJQk10vaDGBMBQkZI3AGTVhzJA
-    a: true as boolean,
-    nested: {
-      foo: 'foo',
-      a: { b: 'string' },
-    },
-  })).bind(null, true) // force always a fresh instance
+  const useStore = () => {
+    // create a new store
+    setActiveReq({})
+    return createStore('main', () => ({
+      a: true,
+      nested: {
+        foo: 'foo',
+        a: { b: 'string' },
+      },
+    }))()
+  }
 
   it('patches a property without touching the rest', () => {
     const store = useStore()
diff --git a/__tests__/store.spec.ts b/__tests__/store.spec.ts
index 39ac7d29..e584b990 100644
--- a/__tests__/store.spec.ts
+++ b/__tests__/store.spec.ts
@@ -1,15 +1,17 @@
-import { createStore } from '../src'
+import { createStore, setActiveReq } from '../src'
 
 describe('Store', () => {
-  const useStore = createStore('main', () => ({
-    // TODO: the boolean cas shouldn't be necessary
-    // https://www.typescriptlang.org/play/#code/MYewdgzgLgBCMF4YG8CwAoGWYEMBcMUATgK4CmGAvhhiAHQ6IwBmOANhBehqJLMETI4oZJgAoAlIgB8MMclwFi5GJQk10vaDGBMBQkZI3AGTVhzJA
-    a: true as boolean,
-    nested: {
-      foo: 'foo',
-      a: { b: 'string' },
-    },
-  })).bind(null, true) // force always a fresh instance
+  const useStore = () => {
+    // create a new store
+    setActiveReq({})
+    return createStore('main', () => ({
+      a: true,
+      nested: {
+        foo: 'foo',
+        a: { b: 'string' },
+      },
+    }))()
+  }
 
   it('sets the initial state', () => {
     const store = useStore()
diff --git a/__tests__/subscriptions.spec.ts b/__tests__/subscriptions.spec.ts
index 4dbbb9aa..6b867a93 100644
--- a/__tests__/subscriptions.spec.ts
+++ b/__tests__/subscriptions.spec.ts
@@ -1,9 +1,13 @@
-import { createStore } from '../src'
+import { createStore, setActiveReq } from '../src'
 
 describe('Subscriptions', () => {
-  const useStore = createStore('main', () => ({
-    name: 'Eduardo',
-  })).bind(null, true)
+  const useStore = () => {
+    // create a new store
+    setActiveReq({})
+    return createStore('main', () => ({
+      name: 'Eduardo',
+    }))()
+  }
 
   let store: ReturnType<typeof useStore>
   beforeEach(() => {
diff --git a/src/index.ts b/src/index.ts
index 7c7dc067..4d62a5f8 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,2 +1,2 @@
-export { createStore, CombinedStore } from './store'
+export { createStore, CombinedStore, setActiveReq } from './store'
 export { StateTree, StoreGetter } from './types'
diff --git a/src/store.ts b/src/store.ts
index 49d91cbc..349950c6 100644
--- a/src/store.ts
+++ b/src/store.ts
@@ -11,6 +11,8 @@ import {
 } from './types'
 import { useStoreDevtools } from './devtools'
 
+const isClient = typeof window != 'undefined'
+
 function innerPatch<T extends StateTree>(
   target: T,
   patchToApply: DeepPartial<T>
@@ -41,12 +43,13 @@ export type CombinedStore<
   G extends Record<string, StoreGetter<S>>
 > = Store<Id, S> & StoreGetters<S, G>
 
+// TODO: allow buildStore to start with an initial state for hydration
+
 /**
  * Creates a store instance
  * @param id unique identifier of the store, like a name. eg: main, cart, user
  * @param initialState initial state applied to the store, Must be correctly typed to infer typings
  */
-
 export function buildStore<
   Id extends string,
   S extends StateTree,
@@ -142,6 +145,13 @@ export function buildStore<
   return store
 }
 
+/**
+ * setActiveReq must be called to handle SSR at the top of functions like `fetch`, `setup`, `serverPrefetch` and others
+ */
+export let activeReq: object = {}
+export const setActiveReq = (req: object) => (activeReq = req)
+export const getActiveReq = () => activeReq
+
 /**
  * The api needs more work we must be able to use the store easily in any
  * function by calling `useStore` to get the store Instance and we also need to
@@ -169,18 +179,19 @@ export function createStore<
   // TODO: do we really need the boolean version for SSR? Using the request would be better
   // as it allows async code like pending requests to use the correct store version.
   return function useStore(
-    req?: object | boolean,
+    force?: boolean,
     initialStates?: Record<Id, S>
   ): CombinedStore<Id, S, G> {
-    if (!req || typeof req === 'boolean') {
-      if (!store || req) store = buildStore(id, buildState, getters)
+    const req = getActiveReq()
+    let stores = storesMap.get(req)
+    if (!stores) storesMap.set(req, (stores = {}))
+
+    store = stores[id]
+    if (!store) {
+      stores[id] = store = buildStore(id, buildState, getters)
+      // hydrate state
       if (initialStates && initialStates[id]) store.state = initialStates[id]
-      useStoreDevtools(store)
-    } else {
-      let stores = storesMap.get(req)
-      if (!stores) storesMap.set(req, (stores = {}))
-      store = stores[id]
-      if (!store) stores[id] = store = buildStore(id, buildState, getters)
+      if (isClient) useStoreDevtools(store)
     }
 
     return store