feat(recipes): redux recipe (#117 by @Jpoliachik)

* add redux recipe

* additional clarity and refined examples

* add full filepath for store.ts

* add info about updating ignite generator templates

Author: Jpoliachik

docs/recipes/Redux.md

@@ -0,0 +1,363 @@
+---
+title: Redux
+description: How to migrate a Mobx-State-Tree project to Redux
+tags:
+  - Redux
+  - MobX
+  - State Management
+last_update:
+  author: Justin Poliachik
+publish_date: 2024-01-16
+---
+
+# Redux
+
+This guide will show you how to migrate a Mobx-State-Tree project (Ignite's default) to Redux, using a newly created Ignite project as our example:
+
+```terminal
+npx ignite-cli new ReduxApp --yes --removeDemo
+```
+
+If you are migrating an existing project these steps still apply, but you may need to migrate your existing state tree and other additional functionality.
+
+## Remove Mobx-State-Tree
+
+- Remove all Mobx-related dependencies from `package.json`, then run `yarn` or `npm i`
+
+```diff
+--"mobx": "6.10.2",
+--"mobx-react-lite": "4.0.5",
+--"mobx-state-tree": "5.3.0",
+
+--"reactotron-mst": "3.1.5",
+```
+
+- Ignite created default boilerplate Mobx-State-Tree files in the `models/` directory. Remove this entire directory and all files within it, these are not needed for Redux.
+
+- In `devtools/ReactotronConfig.ts` remove the `reactotron-mst` plugin. We can come back to [add a Redux plugin](#reactotron-support) later.
+
+```diff
+--import { mst } from "reactotron-mst"
+
+...
+
+const reactotron = Reactotron.configure({
+  name: require("../../package.json").name,
+  onConnect: () => {
+    /** since this file gets hot reloaded, let's clear the past logs every time we connect */
+    Reactotron.clear()
+  },
+--}).use(
+--  mst({
+--    /** ignore some chatty `mobx-state-tree` actions  */
+--    filter: (event) => /postProcessSnapshot|@APPLY_SNAPSHOT/.test(event.name) === false,
+--  }),
+--)
+++})
+```
+
+- Remove all `observer()` components and reformat as normal React components. Do a project-wide search for `observer(` and replace each component instance with the following pattern:
+
+```diff
+--import { observer } from "mobx-react-lite"
+
+--export const WelcomeScreen: FC<WelcomeScreenProps> = observer(function WelcomeScreen(props) {
+++export const WelcomeScreen: FC<WelcomeScreenProps> = (props) => {
+    ...
+--})
+++}
+```
+
+- (optional) Don't forget to update your [Ignite Generator Templates](https://docs.infinite.red/ignite-cli/concept/Generator-Templates/)!
+  - Follow the same pattern to replace `observer()`. This will allow you to quickly generate screens and components via `npx ignite-cli generate screen NewScreen` and `npx ignite-cli generate component NewComponent` and use your updated syntax. (You can customize these however you like!)
+  - Update `ignite/templates/component/NAME.tsx.ejs` and `ignite/templates/screen/NAMEScreen.tsx.ejs`
+
+```diff
+--import { observer } from "mobx-react-lite"
+
+--export const <%= props.pascalCaseName %> = observer(function <%= props.pascalCaseName %>(props: <%= props.pascalCaseName %>Props) {
+++export const <%= props.pascalCaseName %> = (props: <%= props.pascalCaseName %>Props) => {
+    ...
+--})
+++}
+```
+
+- Remove old Mobx-State-Tree store initialization / hydration code in `app.tsx`.
+- Call `hideSplashScreen` in a `useEffect` so the app loads for now. We'll replace this code when we add [persistence](#persistence) below.
+
+```diff
+--import { useInitialRootStore } from "./models"
+
+--const { rehydrated } = useInitialRootStore(() => {
+--setTimeout(hideSplashScreen, 500)
+--})
+++useEffect(() => {
+++    setTimeout(hideSplashScreen, 500)
+++}, [])
+
+--if (!rehydrated || !isNavigationStateRestored || !areFontsLoaded) return null
+++if (!isNavigationStateRestored || !areFontsLoaded) return null
+```
+
+You should be able to build and run your app! It won't have any data...but it's a good idea to check that it successfully runs before we move on.
+
+## Add Redux
+
+#### Install dependencies
+
+[redux-tooklit is the current recommended approach](https://redux.js.org/introduction/getting-started#redux-toolkit), and you'll also need `react-redux` bindings for your React Native app.
+
+```bash
+yarn add @reduxjs/toolkit
+yarn add react-redux
+```
+
+#### Create Store
+
+- In a new file `app/store.ts`, create your Redux store.
+  - Create an initial store. We're using [Redux Toolkit's `configureStore`](https://redux-toolkit.js.org/usage/usage-guide#simplifying-store-setup-with-configurestore) here for simplicity.
+  - Export Typescript helpers for the rest of your app to stay type safe
+
+`store.ts`
+
+```typescript
+import { configureStore } from "@reduxjs/toolkit";
+import { TypedUseSelectorHook, useDispatch, useSelector } from "react-redux";
+import counterReducer from "./counterSlice";
+
+export const store = configureStore({
+  reducer: {
+    counter: counterReducer,
+    // add other state here
+  },
+});
+
+// Infer the `RootState` and `AppDispatch` types from the store itself
+export type RootState = ReturnType<typeof store.getState>;
+export type AppDispatch = typeof store.dispatch;
+
+// Use throughout app instead of plain `useDispatch` and `useSelector` for type safety
+type DispatchFunc = () => AppDispatch;
+export const useAppDispatch: DispatchFunc = useDispatch;
+export const useAppSelector: TypedUseSelectorHook<RootState> = useSelector;
+```
+
+#### Add State
+
+- Add your state reducers or [slices](https://redux-toolkit.js.org/usage/usage-guide#creating-slices-of-state). We'll create a simple `counter` slice for this example.
+- If you have an existing state tree with Mobx-State-Tree, you'll need to convert your tree into a series of Redux reducers.
+  - Note: Redux does not define or validate your models like Mobx-State-Tree does. It is up to you to ensure the correct data is being set in your reducers.
+
+`counterSlice.ts`
+
+```typescript
+import { createSlice } from "@reduxjs/toolkit";
+
+// Define a type for the slice state
+interface CounterState {
+  value: number;
+}
+
+// Define the initial state using that type
+const initialState: CounterState = {
+  value: 0,
+};
+
+export const counterSlice = createSlice({
+  name: "counter",
+  // `createSlice` will infer the state type from the `initialState` argument
+  initialState,
+  reducers: {
+    increment: (state) => {
+      state.value += 1;
+    },
+    decrement: (state) => {
+      state.value -= 1;
+    },
+  },
+});
+
+export const { increment, decrement } = counterSlice.actions;
+export default counterSlice.reducer;
+```
+
+#### Add Redux Provider
+
+In `app.tsx`, wrap your `AppNavigator` with the react-redux Provider component
+
+```jsx
+import { Provider } from "react-redux";
+import { store } from "./store/store";
+
+...
+
+<Provider store={store}>
+  <AppNavigator
+    linking={linking}
+    initialState={initialNavigationState}
+    onStateChange={onNavigationStateChange}
+  />
+</Provider>
+```
+
+#### Hook up Components
+
+You can now use selectors to grab data and `dispatch()` to execute actions within your components. Here's an example:
+
+- Remember to use our exported `useAppSelector` and `useAppDispatch` helpers for type safety
+
+`WelcomeScreen.tsx`
+
+```typescript
+import React, { FC } from "react";
+import { View, ViewStyle } from "react-native";
+import { Button, Text } from "app/components";
+import { AppStackScreenProps } from "../navigators";
+import { colors } from "../theme";
+import { useSafeAreaInsetsStyle } from "../utils/useSafeAreaInsetsStyle";
+import { useAppDispatch, useAppSelector } from "app/store/store";
+import { decrement, increment } from "app/store/counterSlice";
+
+interface WelcomeScreenProps extends AppStackScreenProps<"Welcome"> {}
+
+export const WelcomeScreen: FC<WelcomeScreenProps> = () => {
+  const $containerInsets = useSafeAreaInsetsStyle(["top", "bottom"]);
+  const count = useAppSelector((state) => state.counter.value);
+  const dispatch = useAppDispatch();
+  return (
+    <View style={[$containerInsets, $container]}>
+      <Button text="Increment" onPress={() => dispatch(increment())} />
+      <Button text="Decrement" onPress={() => dispatch(decrement())} />
+      <Text text={`Count: ${count}`} />
+    </View>
+  );
+};
+
+const $container: ViewStyle = {
+  flex: 1,
+  backgroundColor: colors.background,
+};
+```
+
+You're now using Redux!
+
+## Persistence
+
+Ignite ships with built-in persistence support for Mobx-State-Tree. We can add similar support for Redux by:
+
+1. Install [`redux-persist`](https://github.com/rt2zz/redux-persist)
+
+```
+yarn add redux-persist
+```
+
+2. Modify `store.ts` to include `redux-persist`
+
+`store.ts`
+
+```typescript
+import { combineReducers, configureStore } from "@reduxjs/toolkit";
+import counterReducer from "./counterSlice";
+import { TypedUseSelectorHook, useDispatch, useSelector } from "react-redux";
+import {
+  persistStore,
+  persistReducer,
+  FLUSH,
+  REHYDRATE,
+  PAUSE,
+  PERSIST,
+  PURGE,
+  REGISTER,
+} from "redux-persist";
+import AsyncStorage from "@react-native-async-storage/async-storage";
+
+const persistConfig = {
+  key: "root",
+  version: 1,
+  storage: AsyncStorage,
+};
+
+const rootReducer = combineReducers({
+  counter: counterReducer,
+});
+
+const persistedReducer = persistReducer(persistConfig, rootReducer);
+
+export const store = configureStore({
+  reducer: persistedReducer,
+  middleware: (getDefaultMiddleware) =>
+    getDefaultMiddleware({
+      serializableCheck: {
+        ignoredActions: [FLUSH, REHYDRATE, PAUSE, PERSIST, PURGE, REGISTER],
+      },
+    }),
+});
+
+export const persistor = persistStore(store);
+
+// Infer the `RootState` and `AppDispatch` types from the store itself
+export type RootState = ReturnType<typeof store.getState>;
+export type AppDispatch = typeof store.dispatch;
+
+// Use throughout app instead of plain `useDispatch` and `useSelector` for type safety
+type DispatchFunc = () => AppDispatch;
+export const useAppDispatch: DispatchFunc = useDispatch;
+export const useAppSelector: TypedUseSelectorHook<RootState> = useSelector;
+```
+
+3. Add a `PersistGate` to `app.tsx` and replace any existing `hideSplashScreen` calls with the `onBeforeLift` callback
+
+`app.tsx`
+
+```typescript
+...
+
+import { persistor, store } from "./store/store"
+import { PersistGate } from "redux-persist/integration/react"
+
+...
+
+function App(props: AppProps) {
+  const { hideSplashScreen } = props
+...
+  const onBeforeLiftPersistGate = () => {
+    // If your initialization scripts run very fast, it's good to show the splash screen for just a bit longer to prevent flicker.
+    // Slightly delaying splash screen hiding for better UX; can be customized or removed as needed,
+    // Note: (vanilla Android) The splash-screen will not appear if you launch your app via the terminal or Android Studio. Kill the app and launch it normally by tapping on the launcher icon. https://stackoverflow.com/a/69831106
+    // Note: (vanilla iOS) You might notice the splash-screen logo change size. This happens in debug/development mode. Try building the app for release.
+    setTimeout(hideSplashScreen, 500)
+  }
+...
+  return (
+    <SafeAreaProvider initialMetrics={initialWindowMetrics}>
+      <ErrorBoundary catchErrors={Config.catchErrors}>
+        <GestureHandlerRootView style={$container}>
+          <Provider store={store}>
+            <PersistGate
+              loading={null}
+              onBeforeLift={onBeforeLiftPersistGate}
+              persistor={persistor}
+            >
+              <AppNavigator
+                linking={linking}
+                initialState={initialNavigationState}
+                onStateChange={onNavigationStateChange}
+              />
+            </PersistGate>
+          </Provider>
+        </GestureHandlerRootView>
+      </ErrorBoundary>
+    </SafeAreaProvider>
+  )
+}
+
+export default App
+```
+
+Your Redux state should now be persisted using AsyncStorage!
+
+## Reactotron Support
+
+Reactotron has a prebuilt plugin for Redux!
+
+[Follow the instructions to install](https://docs.infinite.red/reactotron/plugins/redux/)