Allow configuring a custom event store in React Native tracker (close #1413)

PR #1418

Author: valeriobelli

Diff for: trackers/react-native-tracker/package.json

@@ -43,6 +43,7 @@
     "test": "jest"
   },
   "peerDependencies": {
+    "@react-native-async-storage/async-storage": "~2.0.0",
     "react": "*",
     "react-native": "*",
     "react-native-get-random-values": "^1.11.0"
@@ -51,11 +52,11 @@
     "@snowplow/tracker-core": "workspace:*",
     "@snowplow/browser-tracker-core": "workspace:*",
     "@snowplow/browser-plugin-screen-tracking": "workspace:*",
-    "@react-native-async-storage/async-storage": "~2.0.0",
     "tslib": "^2.3.1",
     "uuid": "^10.0.0"
   },
   "devDependencies": {
+    "@react-native-async-storage/async-storage": "~2.0.0",
     "@snowplow/browser-plugin-snowplow-ecommerce": "workspace:*",
     "@typescript-eslint/eslint-plugin": "~5.15.0",
     "@typescript-eslint/parser": "~5.15.0",

Diff for: trackers/react-native-tracker/src/event_store.ts

@@ -1,17 +1,20 @@
-import { EventStore, newInMemoryEventStore, EventStorePayload } from '@snowplow/tracker-core';
-import { EventStoreConfiguration, TrackerConfiguration } from './types';
-import AsyncStorage from '@react-native-async-storage/async-storage';
+import { EventStore, EventStorePayload, newInMemoryEventStore } from '@snowplow/tracker-core';
+import { AsyncStorage, EventStoreConfiguration, TrackerConfiguration } from './types';
+
+type Configuration = Omit<EventStoreConfiguration, 'asyncStorage'> &
+  TrackerConfiguration & { asyncStorage: AsyncStorage };
 
 export async function newReactNativeEventStore({
   namespace,
   maxEventStoreSize = 1000,
   useAsyncStorageForEventStore: useAsyncStorage = true,
-}: EventStoreConfiguration & TrackerConfiguration): Promise<EventStore> {
+  asyncStorage,
+}: Configuration): Promise<EventStore> {
   const queueName = `snowplow_${namespace}`;
 
   async function newInMemoryEventStoreForReactNative() {
     if (useAsyncStorage) {
-      const data = await AsyncStorage.getItem(queueName);
+      const data = await asyncStorage.getItem(queueName);
       const events: EventStorePayload[] = data ? JSON.parse(data) : [];
       return newInMemoryEventStore({ maxSize: maxEventStoreSize, events });
     } else {
@@ -26,7 +29,7 @@ export async function newReactNativeEventStore({
   async function sync() {
     if (useAsyncStorage) {
       const events = await getAll();
-      await AsyncStorage.setItem(queueName, JSON.stringify(events));
+      await asyncStorage.setItem(queueName, JSON.stringify(events));
     }
   }
 

Diff for: trackers/react-native-tracker/src/plugins/app_install/index.ts

@@ -1,7 +1,7 @@
-import { buildSelfDescribingEvent, CorePluginConfiguration, TrackerCore } from '@snowplow/tracker-core';
-import { AppLifecycleConfiguration, TrackerConfiguration } from '../../types';
+import type { CorePluginConfiguration, TrackerCore } from '@snowplow/tracker-core';
+import { buildSelfDescribingEvent } from '@snowplow/tracker-core';
 import { APPLICATION_INSTALL_EVENT_SCHEMA } from '../../constants';
-import AsyncStorage from '@react-native-async-storage/async-storage';
+import type { AppLifecycleConfiguration, AsyncStorage, TrackerConfiguration } from '../../types';
 
 /**
  * Tracks an application install event on the first run of the app.
@@ -10,14 +10,18 @@ import AsyncStorage from '@react-native-async-storage/async-storage';
  * Event schema: `iglu:com.snowplowanalytics.mobile/application_install/jsonschema/1-0-0`
  */
 export function newAppInstallPlugin(
-  { namespace, installAutotracking = false }: TrackerConfiguration & AppLifecycleConfiguration,
+  {
+    asyncStorage,
+    namespace,
+    installAutotracking = false,
+  }: TrackerConfiguration & AppLifecycleConfiguration & { asyncStorage: AsyncStorage },
   core: TrackerCore
 ): CorePluginConfiguration {
   if (installAutotracking) {
     // Track install event on first run
     const key = `snowplow_${namespace}_install`;
     setTimeout(async () => {
-      const installEvent = await AsyncStorage.getItem(key);
+      const installEvent = await asyncStorage.getItem(key);
       if (!installEvent) {
         core.track(
           buildSelfDescribingEvent({
@@ -27,7 +31,7 @@ export function newAppInstallPlugin(
             },
           })
         );
-        await AsyncStorage.setItem(key, new Date().toISOString());
+        await asyncStorage.setItem(key, new Date().toISOString());
       }
     }, 0);
   }

Diff for: trackers/react-native-tracker/src/plugins/session/index.ts

@@ -1,8 +1,7 @@
 import { CorePluginConfiguration, PayloadBuilder } from '@snowplow/tracker-core';
-import { SessionConfiguration, SessionState, TrackerConfiguration } from '../../types';
-import AsyncStorage from '@react-native-async-storage/async-storage';
 import { v4 as uuidv4 } from 'uuid';
 import { BACKGROUND_EVENT_SCHEMA, CLIENT_SESSION_ENTITY_SCHEMA, FOREGROUND_EVENT_SCHEMA } from '../../constants';
+import { AsyncStorage, SessionConfiguration, SessionState, TrackerConfiguration } from '../../types';
 import { getUsefulSchema } from '../../utils';
 
 interface StoredSessionState {
@@ -19,13 +18,13 @@ interface SessionPlugin extends CorePluginConfiguration {
   startNewSession: () => Promise<void>;
 }
 
-async function storeSessionState(namespace: string, state: StoredSessionState) {
+async function storeSessionState(namespace: string, state: StoredSessionState, asyncStorage: AsyncStorage) {
   const { userId, sessionId, sessionIndex } = state;
-  await AsyncStorage.setItem(`snowplow_${namespace}_session`, JSON.stringify({ userId, sessionId, sessionIndex }));
+  await asyncStorage.setItem(`snowplow_${namespace}_session`, JSON.stringify({ userId, sessionId, sessionIndex }));
 }
 
-async function resumeStoredSession(namespace: string): Promise<SessionState> {
-  const storedState = await AsyncStorage.getItem(`snowplow_${namespace}_session`);
+async function resumeStoredSession(namespace: string, asyncStorage: AsyncStorage): Promise<SessionState> {
+  const storedState = await asyncStorage.getItem(`snowplow_${namespace}_session`);
   if (storedState) {
     const state = JSON.parse(storedState) as StoredSessionState;
     return {
@@ -48,18 +47,19 @@ async function resumeStoredSession(namespace: string): Promise<SessionState> {
 /**
  * Creates a new session plugin for tracking the session information.
  * The plugin will add the session context to all events and start a new session if the current one has timed out.
- * 
- * The session state is stored in AsyncStorage.
+ *
+ * The session state is stored in the defined application storage.
  * Each restart of the app or creation of a new tracker instance will trigger a new session with reference to the previous session.
  */
 export async function newSessionPlugin({
+  asyncStorage,
   namespace,
   sessionContext = true,
   foregroundSessionTimeout,
   backgroundSessionTimeout,
-}: TrackerConfiguration & SessionConfiguration): Promise<SessionPlugin> {
-  let sessionState = await resumeStoredSession(namespace);
-  await storeSessionState(namespace, sessionState);
+}: TrackerConfiguration & SessionConfiguration & { asyncStorage: AsyncStorage }): Promise<SessionPlugin> {
+  let sessionState = await resumeStoredSession(namespace, asyncStorage);
+  await storeSessionState(namespace, sessionState, asyncStorage);
 
   let inBackground = false;
   let lastUpdateTs = new Date().getTime();
@@ -84,7 +84,7 @@ export async function newSessionPlugin({
     const timeDiff = now.getTime() - lastUpdateTs;
     if (timeDiff > getTimeoutMs()) {
       startNewSession();
-      storeSessionState(namespace, sessionState);
+      storeSessionState(namespace, sessionState, asyncStorage);
     }
     lastUpdateTs = now.getTime();
 

Diff for: trackers/react-native-tracker/src/tracker.ts

@@ -33,38 +33,64 @@ import { newPlatformContextPlugin } from './plugins/platform_context';
 import { newAppLifecyclePlugin } from './plugins/app_lifecycle';
 import { newAppInstallPlugin } from './plugins/app_install';
 import { newAppContextPlugin } from './plugins/app_context';
+import DefaultAsyncStorage from '@react-native-async-storage/async-storage';
 
 const initializedTrackers: Record<string, { tracker: ReactNativeTracker; core: TrackerCore }> = {};
 
+type SetPropertiesAsNonNullable<Obj, Properties extends keyof Obj> = Omit<Obj, Properties> & {
+  [K in Properties]-?: NonNullable<Obj[K]>;
+};
+
+type Configuration = TrackerConfiguration &
+  EmitterConfiguration &
+  SessionConfiguration &
+  SubjectConfiguration &
+  EventStoreConfiguration &
+  ScreenTrackingConfiguration &
+  PlatformContextConfiguration &
+  DeepLinkConfiguration &
+  AppLifecycleConfiguration;
+
+type NormalizedConfiguration = SetPropertiesAsNonNullable<
+  Configuration,
+  'asyncStorage' | 'devicePlatform' | 'encodeBase64' | 'eventStore' | 'plugins'
+>;
+
+const normalizeTrackerConfiguration = async (configuration: Configuration): Promise<NormalizedConfiguration> => {
+  const eventStore = configuration.eventStore ?? (await newReactNativeEventStore(configuration));
+  const asyncStorage = configuration.asyncStorage ?? DefaultAsyncStorage;
+  const plugins = configuration.plugins ?? [];
+  const devicePlatform = configuration.devicePlatform ?? 'mob';
+  const encodeBase64 = configuration.encodeBase64 ?? false;
+
+  return {
+    ...configuration,
+    devicePlatform,
+    encodeBase64,
+    asyncStorage,
+    eventStore,
+    plugins,
+  };
+};
+
 /**
  * Creates a new tracker instance with the given configuration
  * @param configuration - Configuration for the tracker
  * @returns Tracker instance
  */
-export async function newTracker(
-  configuration: TrackerConfiguration &
-    EmitterConfiguration &
-    SessionConfiguration &
-    SubjectConfiguration &
-    EventStoreConfiguration &
-    ScreenTrackingConfiguration &
-    PlatformContextConfiguration &
-    DeepLinkConfiguration &
-    AppLifecycleConfiguration
-): Promise<ReactNativeTracker> {
-  const { namespace, appId, encodeBase64 = false } = configuration;
-  if (configuration.eventStore === undefined) {
-    configuration.eventStore = await newReactNativeEventStore(configuration);
-  }
+export async function newTracker(configuration: Configuration): Promise<ReactNativeTracker> {
+  const normalizedConfiguration = await normalizeTrackerConfiguration(configuration);
+
+  const { namespace, appId, encodeBase64 } = normalizedConfiguration;
 
-  const emitter = newEmitter(configuration);
+  const emitter = newEmitter(normalizedConfiguration);
   const callback = (payload: PayloadBuilder): void => {
     emitter.input(payload.build());
   };
 
   const core = trackerCore({ base64: encodeBase64, callback });
 
-  core.setPlatform(configuration.devicePlatform ?? 'mob');
+  core.setPlatform(normalizedConfiguration.devicePlatform);
   core.setTrackerVersion('rn-' + version);
   core.setTrackerNamespace(namespace);
   if (appId) {
@@ -73,31 +99,31 @@ export async function newTracker(
 
   const { addPlugin } = newPlugins(namespace, core);
 
-  const sessionPlugin = await newSessionPlugin(configuration);
+  const sessionPlugin = await newSessionPlugin(normalizedConfiguration);
   addPlugin(sessionPlugin);
 
-  const deepLinksPlugin = await newDeepLinksPlugin(configuration, core);
+  const deepLinksPlugin = newDeepLinksPlugin(normalizedConfiguration, core);
   addPlugin(deepLinksPlugin);
 
-  const subject = newSubject(core, configuration);
+  const subject = newSubject(core, normalizedConfiguration);
   addPlugin(subject.subjectPlugin);
 
-  const screenPlugin = ScreenTrackingPlugin(configuration);
+  const screenPlugin = ScreenTrackingPlugin(normalizedConfiguration);
   addPlugin({ plugin: screenPlugin });
 
-  const platformContextPlugin = await newPlatformContextPlugin(configuration);
+  const platformContextPlugin = await newPlatformContextPlugin(normalizedConfiguration);
   addPlugin(platformContextPlugin);
 
-  const lifecyclePlugin = await newAppLifecyclePlugin(configuration, core);
+  const lifecyclePlugin = await newAppLifecyclePlugin(normalizedConfiguration, core);
   addPlugin(lifecyclePlugin);
 
-  const installPlugin = newAppInstallPlugin(configuration, core);
+  const installPlugin = newAppInstallPlugin(normalizedConfiguration, core);
   addPlugin(installPlugin);
 
-  const appContextPlugin = newAppContextPlugin(configuration);
+  const appContextPlugin = newAppContextPlugin(normalizedConfiguration);
   addPlugin(appContextPlugin);
 
-  (configuration.plugins ?? []).forEach((plugin) => addPlugin({ plugin }));
+  normalizedConfiguration.plugins.forEach((plugin) => addPlugin({ plugin }));
 
   const tracker: ReactNativeTracker = {
     ...newTrackEventFunctions(core),

Diff for: trackers/react-native-tracker/src/types.ts

@@ -7,6 +7,11 @@ import {
   StructuredEvent,
 } from '@snowplow/tracker-core';
 
+export interface AsyncStorage {
+  getItem: (key: string) => Promise<string | null>;
+  setItem: (key: string, value: string) => Promise<void>;
+}
+
 /**
  * Configuration for the event store
  */
@@ -24,6 +29,15 @@ export interface EventStoreConfiguration {
    * @defaultValue true
    */
   useAsyncStorageForEventStore?: boolean;
+
+  /**
+   * The Async storage implementation.
+   * In environments where AsyncStorage is not available or where another kind of storage is used,
+   * you can provide a custom implementation.
+   *
+   * @defaultValue AsyncStorage from {@link https://react-native-async-storage.github.io/async-storage/ @react-native-async-storage/async-storage}
+   * */
+  asyncStorage?: AsyncStorage;
 }
 
 /**
@@ -918,7 +932,6 @@ export {
   ContextGenerator,
   ContextFilter,
   EventPayloadAndContext,
-  EventStore,
   EventStoreIterator,
   EventStorePayload,
   TrackerCore,

Diff for: trackers/react-native-tracker/test/event_store.test.ts

@@ -1,8 +1,23 @@
+import AsyncStorage from '@react-native-async-storage/async-storage';
 import { newReactNativeEventStore } from '../src/event_store';
 
+function createAsyncStorageMock() {
+  const storageState: Record<string, string> = {};
+
+  return {
+    getItem: (key: string) => Promise.resolve(storageState[key] ?? null),
+    setItem: (key: string, value: string) => {
+      storageState[key] = value;
+
+      return Promise.resolve();
+    },
+  };
+}
+
 describe('React Native event store', () => {
   it('keeps track of added events', async () => {
     const eventStore = await newReactNativeEventStore({
+      asyncStorage: AsyncStorage,
       namespace: 'test',
     });
 
@@ -21,9 +36,11 @@ describe('React Native event store', () => {
 
   it('separates event stores by namespace', async () => {
     const eventStore1 = await newReactNativeEventStore({
+      asyncStorage: AsyncStorage,
       namespace: 'test1',
     });
     const eventStore2 = await newReactNativeEventStore({
+      asyncStorage: AsyncStorage,
       namespace: 'test2',
     });
 
@@ -39,13 +56,33 @@ describe('React Native event store', () => {
 
   it('syncs with AsyncStorage', async () => {
     const eventStore1 = await newReactNativeEventStore({
+      asyncStorage: AsyncStorage,
+      namespace: 'testA',
+    });
+
+    await eventStore1.add({ payload: { e: 'pv' } });
+    await eventStore1.add({ payload: { e: 'pp' } });
+
+    const eventStore2 = await newReactNativeEventStore({
+      asyncStorage: AsyncStorage,
+      namespace: 'testA',
+    });
+
+    expect(await eventStore2.count()).toBe(2);
+  });
+
+  it('syncs with the custom async storage implementation', async () => {
+    const asyncStorage = createAsyncStorageMock();
+    const eventStore1 = await newReactNativeEventStore({
+      asyncStorage,
       namespace: 'testA',
     });
 
     await eventStore1.add({ payload: { e: 'pv' } });
     await eventStore1.add({ payload: { e: 'pp' } });
 
     const eventStore2 = await newReactNativeEventStore({
+      asyncStorage,
       namespace: 'testA',
     });