docs: deprecation guide for moving to firebase-js-sdk v9 modular API

docs/index.md

@@ -4,6 +4,9 @@ description: Welcome to React Native Firebase! To get started, you must first se
 next: /typescript
 ---
 
+> React Native Firebase has begun to deprecate the namespaced API (i.e firebase-js-sdk `< v9` chaining API). React Native Firebase will be moving to the modular API (i.e. firebase-js-sdk `>= v9`) in the next major release. See [migration guide]() for more information.
+
+
 React Native Firebase is the officially recommended collection of packages that brings React Native support for all Firebase services on both Android and iOS apps.
 
 React Native Firebase fully supports React Native apps built using [React Native CLI](https://reactnative.dev/docs/environment-setup?guide=native) or using [Expo](https://docs.expo.dev/).

docs/migrating-to-v22.md

@@ -0,0 +1,54 @@
+---
+title: Migrating to v22
+description: Migrate to React Native Firebase v22
+next: /typescript
+previous: /
+---
+
+# Switching off warning logs
+
+You may notice an influx of console warning logs as we continue deprecating all existing namespaced API. If you would like to switch these logs off, you may set the following global property to `true` anywhere before you initialise Firebase.
+
+```js
+globalThis.RNFB_SILENCE_V8_DEPRECATION_WARNINGS = true;
+```
+
+# Migrating to React Native modular API
+
+React Native Firebase does not currently have documentation for  modular API. A refresh of the React Native Firebase documentation is something we will be aiming to achieve in the near future. We're keen to move the project to TypeScript which will then allow us to generate reference documentation from those types.
+
+However, if you are familiar with the Firebase JS SDK, it will be a much smoother process. React Native Firebase is using the same API as can be found on the official [Firebase JS SDK modular API documentation](https://firebase.google.com/docs/reference/js).
+
+## Firestore example
+
+## deprecated namespaced Query
+
+```js
+import firestore from '@react-native-firebase/firestore';
+
+const db = firestore();
+
+const querySnapshot = await db.collection("cities").where("capital", "==", true).get();
+
+querySnapshot.forEach((doc) => {
+  console.log(doc.id, " => ", doc.data());
+});
+```
+
+## modular Query
+
+```js
+import { collection, query, where, getDocs, getFirestore } from "@react-native-firebase/firestore";
+
+const db = getFirestore();
+
+const q = query(collection(db, "cities"), where("capital", "==", true));
+
+const querySnapshot = await getDocs(q);
+
+querySnapshot.forEach((doc) => {
+  console.log(doc.id, " => ", doc.data());
+});
+```
+
+For more examples of requesting data, see the official Firebase documentation for [Get data with Cloud Firestore](https://firebase.google.com/docs/firestore/query-data/get-data). You will find code snippets for "Web namespaced API" and "Web modular API". You can find code snippets for both namespaced API and modular API through out the Firebase web documentation.

packages/app/lib/common/index.js

@@ -225,8 +225,11 @@ export function deprecationConsoleWarning(nameSpace, methodName, instanceName, i
       const deprecatedMethod = instanceMap[methodName];
       if (instanceMap && deprecatedMethod) {
         const message = createMessage(nameSpace, methodName, instanceName);
-        // eslint-disable-next-line no-console
-        console.warn(message);
+
+        if (!globalThis.RNFB_SILENCE_V8_DEPRECATION_WARNINGS) {
+          // eslint-disable-next-line no-console
+          console.warn(message);
+        }
       }
     }
   }
@@ -367,6 +370,8 @@ export function warnIfNotModularCall(args, replacementMethodName = '') {
     message += ` Please use \`${replacementMethodName}\` instead.`;
   }
 
-  // eslint-disable-next-line no-console
-  console.warn(message);
+  if (!globalThis.RNFB_SILENCE_V8_DEPRECATION_WARNINGS) {
+    // eslint-disable-next-line no-console
+    console.warn(message);
+  }
 }