feat: flush when online

README.md

@@ -51,12 +51,12 @@ The hassle-free way to add Segment analytics to your React-Native app.
 
 ## Installation
 
-Install `@segment/analytics-react-native`,  [`@segment/sovran-react-native`](https://github.com/segmentio/analytics-react-native/blob/master/packages/sovran) and [`react-native-get-random-values`](https://github.com/LinusU/react-native-get-random-values):
+Install `@segment/analytics-react-native`,  [`@segment/sovran-react-native`](https://github.com/segmentio/analytics-react-native/blob/master/packages/sovran), [`react-native-get-random-values`](https://github.com/LinusU/react-native-get-random-values) and [`@react-native-community/netinfo`](https://github.com/react-native-netinfo/react-native-netinfo):
 
 ```sh
-yarn add @segment/analytics-react-native @segment/sovran-react-native react-native-get-random-values
+yarn add @segment/analytics-react-native @segment/sovran-react-native react-native-get-random-values @react-native-community/netinfo
 # or
-npm install --save @segment/analytics-react-native @segment/sovran-react-native react-native-get-random-values
+npm install --save @segment/analytics-react-native @segment/sovran-react-native react-native-get-random-values @react-native-community/netinfo
 ```
 
 If you want to use the default persistor for the Segment Analytics client, you also have to install [`react-native-async-storage/async-storage`](https://github.com/react-native-async-storage/async-storage).

example/ios/Podfile.lock

@@ -222,6 +222,8 @@ PODS:
     - glog
   - react-native-get-random-values (1.8.0):
     - React-Core
+  - react-native-netinfo (9.4.1):
+    - React-Core
   - react-native-safe-area-context (3.4.1):
     - React-Core
   - react-native-tracking-transparency (0.1.1):
@@ -331,6 +333,7 @@ DEPENDENCIES:
   - React-jsinspector (from `../node_modules/react-native/ReactCommon/jsinspector`)
   - React-logger (from `../node_modules/react-native/ReactCommon/logger`)
   - react-native-get-random-values (from `../node_modules/react-native-get-random-values`)
+  - "react-native-netinfo (from `../node_modules/@react-native-community/netinfo`)"
   - react-native-safe-area-context (from `../node_modules/react-native-safe-area-context`)
   - react-native-tracking-transparency (from `../node_modules/react-native-tracking-transparency`)
   - React-perflogger (from `../node_modules/react-native/ReactCommon/reactperflogger`)
@@ -399,6 +402,8 @@ EXTERNAL SOURCES:
     :path: "../node_modules/react-native/ReactCommon/logger"
   react-native-get-random-values:
     :path: "../node_modules/react-native-get-random-values"
+  react-native-netinfo:
+    :path: "../node_modules/@react-native-community/netinfo"
   react-native-safe-area-context:
     :path: "../node_modules/react-native-safe-area-context"
   react-native-tracking-transparency:
@@ -466,6 +471,7 @@ SPEC CHECKSUMS:
   React-jsinspector: 8134ee22182b8dd98dc0973db6266c398103ce6c
   React-logger: 1e7ac909607ee65fd5c4d8bea8c6e644f66b8843
   react-native-get-random-values: a6ea6a8a65dc93e96e24a11105b1a9c8cfe1d72a
+  react-native-netinfo: fefd4e98d75cbdd6e85fc530f7111a8afdf2b0c5
   react-native-safe-area-context: 9e40fb181dac02619414ba1294d6c2a807056ab9
   react-native-tracking-transparency: b2029ff756f1128b1f2c7c7c7f3003bc3c950f9f
   React-perflogger: 8e832d4e21fdfa613033c76d58d7e617341e804b

example/package.json

@@ -21,6 +21,7 @@
   },
   "dependencies": {
     "@react-native-async-storage/async-storage": "^1.15.7",
+    "@react-native-community/netinfo": "^9.4.1",
     "@react-native-community/masked-view": "^0.1.11",
     "@react-navigation/native": "^6.0.2",
     "@react-navigation/stack": "^6.0.7",

example/yarn.lock

@@ -1738,6 +1738,11 @@
   resolved "https://registry.yarnpkg.com/@react-native-community/masked-view/-/masked-view-0.1.11.tgz#2f4c6e10bee0786abff4604e39a37ded6f3980ce"
   integrity sha512-rQfMIGSR/1r/SyN87+VD8xHHzDYeHaJq6elOSCAD+0iLagXkSI2pfA0LmSXP21uw5i3em7GkkRjfJ8wpqWXZNw==
 
+"@react-native-community/netinfo@^9.4.1":
+  version "9.4.1"
+  resolved "https://registry.yarnpkg.com/@react-native-community/netinfo/-/netinfo-9.4.1.tgz#7b880758adca65fe47ee866cf7b00416b9dcc192"
+  integrity sha512-dAbY5mfw+6Kas/GJ6QX9AZyY+K+eq9ad4Su6utoph/nxyH3whp5cMSgRNgE2VhGQVRZ/OG0qq3IaD3+wzoqJXw==
+
 "@react-native/assets@1.0.0":
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/@react-native/assets/-/assets-1.0.0.tgz#c6f9bf63d274bafc8e970628de24986b30a55c8e"

packages/core/package.json

@@ -56,6 +56,7 @@
   "peerDependencies": {
     "react-native-get-random-values": "1.x",
     "@react-native-async-storage/async-storage": "1.x",
+    "@react-native-community/netinfo": "9.x",
     "react": "*",
     "react-native": "*"
   },
@@ -68,6 +69,7 @@
     "@babel/core": "^7.12.9",
     "@babel/runtime": "^7.12.5",
     "@react-native-community/eslint-config": "^2.0.0",
+    "@react-native-community/netinfo": "^9.4.1",
     "@semantic-release/changelog": "^6.0.1",
     "@semantic-release/commit-analyzer": "^9.0.2",
     "@semantic-release/git": "^10.0.1",

packages/core/src/analytics.ts

@@ -23,6 +23,7 @@ import {
   CountFlushPolicy,
   Observable,
   TimerFlushPolicy,
+  OnlineFlushPolicy,
 } from './flushPolicies';
 import { FlushPolicyExecuter } from './flushPolicies/flush-policy-executer';
 import type { DestinationPlugin, PlatformPlugin, Plugin } from './plugin';
@@ -743,6 +744,8 @@ export class SegmentClient {
       }
     }
 
+    flushPolicies.push(new OnlineFlushPolicy());
+
     this.flushPolicyExecuter = new FlushPolicyExecuter(flushPolicies, () => {
       void this.flush();
     });

packages/core/src/flushPolicies/__tests__/online-flush-policy.test.ts

@@ -0,0 +1,35 @@
+import type {
+  NetInfoChangeHandler,
+  NetInfoState,
+} from '@react-native-community/netinfo';
+import { OnlineFlushPolicy } from '../online-flush-policy';
+
+let netInfoListener: NetInfoChangeHandler;
+jest.mock('@react-native-community/netinfo', () => ({
+  addEventListener: (cb: NetInfoChangeHandler) => {
+    netInfoListener = cb;
+  },
+}));
+
+describe('OnlineFlushPolicy', () => {
+  it('triggers a flush when device (re-)connects to network', () => {
+    const policy = new OnlineFlushPolicy();
+
+    policy.start();
+
+    const observer = jest.fn();
+
+    policy.shouldFlush.onChange(observer);
+
+    policy.onEvent();
+    policy.onEvent();
+    policy.onEvent();
+
+    expect(observer).not.toHaveBeenCalled();
+
+    // lets signal that the device is now connected
+    netInfoListener({ isConnected: true } as NetInfoState);
+
+    expect(observer).toHaveBeenCalledWith(true);
+  });
+});

packages/core/src/flushPolicies/index.ts

@@ -3,3 +3,4 @@ export * from './count-flush-policy';
 export * from './timer-flush-policy';
 export * from './startup-flush-policy';
 export * from './background-flush-policy';
+export * from './online-flush-policy';

packages/core/src/flushPolicies/online-flush-policy.ts

@@ -0,0 +1,25 @@
+import NetInfo, { NetInfoState } from '@react-native-community/netinfo';
+import { FlushPolicyBase } from './types';
+
+/**
+ * OnlineFlushPolicy uploads events when the device (re-)connects to network
+ */
+export class OnlineFlushPolicy extends FlushPolicyBase {
+  private unsubscribe: (() => void) | undefined;
+
+  start(): void {
+    this.unsubscribe = NetInfo.addEventListener((state) => {
+      if (state.isConnected === true) {
+        this.shouldFlush.value = true;
+      }
+    });
+  }
+
+  end(): void {
+    this.unsubscribe?.();
+  }
+
+  onEvent(): void {
+    // not applicable
+  }
+}

packages/core/src/plugins/SegmentDestination.ts

@@ -1,3 +1,4 @@
+import NetInfo from '@react-native-community/netinfo';
 import { DestinationPlugin } from '../plugin';
 import {
   PluginType,
@@ -26,7 +27,7 @@ export class SegmentDestination extends DestinationPlugin {
   private isReady = false;
 
   private sendEvents = async (events: SegmentEvent[]): Promise<void> => {
-    if (!this.isReady) {
+    if (!this.isReady || (await NetInfo.fetch()).isConnected === false) {
       // We're not sending events until Segment has loaded all settings
       return Promise.resolve();
     }

yarn.lock

@@ -2403,6 +2403,11 @@
   resolved "https://registry.yarnpkg.com/@react-native-community/eslint-plugin/-/eslint-plugin-1.2.0.tgz#7d6d789ae8edf73dc9bed1246cd48277edea8066"
   integrity sha512-o6aam+0Ug1xGK3ABYmBm0B1YuEKfM/5kaoZO0eHbZwSpw9UzDX4G5y4Nx/K20FHqUmJHkZmLvOUFYwN4N+HqKA==
 
+"@react-native-community/netinfo@^9.4.1":
+  version "9.4.1"
+  resolved "https://registry.yarnpkg.com/@react-native-community/netinfo/-/netinfo-9.4.1.tgz#7b880758adca65fe47ee866cf7b00416b9dcc192"
+  integrity sha512-dAbY5mfw+6Kas/GJ6QX9AZyY+K+eq9ad4Su6utoph/nxyH3whp5cMSgRNgE2VhGQVRZ/OG0qq3IaD3+wzoqJXw==
+
 "@react-native-firebase/analytics@^17.3.2":
   version "17.3.2"
   resolved "https://registry.yarnpkg.com/@react-native-firebase/analytics/-/analytics-17.3.2.tgz#31ddb8b349f073b540d6e15ac2c4216439b39390"