feat(analytics): add method to retrieve the app instance id from the …

docs/analytics/usage/index.md

@@ -120,6 +120,18 @@ with any of the following event names will throw an error.
 | `ad_click`             | `ad_query`                | `ad_exposure`       |
 | `adunit_exposure`      | `ad_activeiew`            |
 
+## App instance id
+
+Below is an example showing how to retrieve the app instance id of the application. This will return null on android
+if FirebaseAnalytics.ConsentType.ANALYTICS_STORAGE has been set to FirebaseAnalytics.ConsentStatus.DENIED and null on
+iOS if ConsentType.analyticsStorage has been set to ConsentStatus.denied.
+
+```jsx
+import analytics from '@react-native-firebase/analytics';
+// ...
+const appInstanceId = await analytics().getAppInstanceId();
+```
+
 # firebase.json
 
 ## Disable Auto-Initialization

packages/analytics/android/src/main/java/io/invertase/firebase/analytics/UniversalFirebaseAnalyticsModule.java

@@ -59,6 +59,10 @@ Task<Void> setSessionTimeoutDuration(long milliseconds) {
     });
   }
 
+  Task<String> getAppInstanceId() {
+    return FirebaseAnalytics.getInstance(getContext()).getAppInstanceId();
+  }
+
   Task<Void> setUserId(String id) {
     return Tasks.call(() -> {
       FirebaseAnalytics.getInstance(getContext()).setUserId(id);

packages/analytics/android/src/reactnative/java/io/invertase/firebase/analytics/ReactNativeFirebaseAnalyticsModule.java

@@ -75,6 +75,17 @@ public void setSessionTimeoutDuration(double milliseconds, Promise promise) {
     });
   }
 
+  @ReactMethod
+  public void getAppInstanceId(Promise promise) {
+    module.getAppInstanceId().addOnCompleteListener(task -> {
+      if (task.isSuccessful()) {
+        promise.resolve(task.getResult());
+      } else {
+        rejectPromiseWithExceptionMap(promise, task.getException());
+      }
+    });
+  }
+
   @ReactMethod
   public void setUserId(String id, Promise promise) {
     module.setUserId(id).addOnCompleteListener(task -> {

packages/analytics/e2e/analytics.e2e.js

@@ -58,6 +58,12 @@ describe('analytics()', function () {
     });
   });
 
+  describe('getAppInstanceId()', function () {
+    it('calls native fn without error', async function () {
+      await firebase.analytics().getAppInstanceId();
+    });
+  });
+
   describe('setUserId()', function () {
     it('allows a null values to be set', async function () {
       await firebase.analytics().setUserId(null);

packages/analytics/ios/RNFBAnalytics/RNFBAnalyticsModule.m

@@ -135,6 +135,13 @@ - (dispatch_queue_t)methodQueue {
     return resolve([NSNull null]);
   }
 
+  RCT_EXPORT_METHOD(getAppInstanceId:
+  (RCTPromiseResolveBlock) resolve
+        rejecter:
+        (RCTPromiseRejectBlock) reject) {
+      return resolve([FIRAnalytics appInstanceID]);
+  }
+
 #pragma mark -
 #pragma mark Private methods
 

packages/analytics/lib/index.d.ts

@@ -682,6 +682,19 @@ export namespace FirebaseAnalyticsTypes {
      */
     setSessionTimeoutDuration(milliseconds?: number): Promise<void>;
 
+    /**
+     * Retrieve the app instance id of the application.
+     *
+     * #### Example
+     *
+     * ```js
+     * const appInstanceId = await firebase.analytics().getAppInstanceId();
+     * ```
+     *
+     * @returns Returns the app instance id or null on android if FirebaseAnalytics.ConsentType.ANALYTICS_STORAGE has been set to FirebaseAnalytics.ConsentStatus.DENIED and null on iOS if ConsentType.analyticsStorage has been set to ConsentStatus.denied.
+     */
+    getAppInstanceId(): Promise<string | null>;
+
     /**
      * Gives a user a unique identification.
      *

packages/analytics/lib/index.js

@@ -130,6 +130,10 @@ class FirebaseAnalyticsModule extends FirebaseModule {
     return this.native.setSessionTimeoutDuration(milliseconds);
   }
 
+  getAppInstanceId() {
+    return this.native.getAppInstanceId();
+  }
+
   setUserId(id) {
     if (!isNull(id) && !isString(id)) {
       throw new Error("firebase.analytics().setUserId(*) 'id' expected a string value.");