Add unit tests for capturing lifecycle events

posthog-core/src/index.ts

@@ -93,6 +93,10 @@ export abstract class PostHogCoreStateless {
     }
     this.requestTimeout = options?.requestTimeout ?? 10000 // 10 seconds
     this.disableGeoip = options?.disableGeoip ?? true
+
+    if (options?.__onConstructed) {
+      options.__onConstructed(this)
+    }
   }
 
   protected getCommonEventProperties(): any {

posthog-core/src/types.ts

@@ -1,3 +1,5 @@
+import type { PostHogCoreStateless } from './index'
+
 export type PosthogCoreOptions = {
   // PostHog API host (https://app.posthog.com by default)
   host?: string
@@ -29,6 +31,9 @@ export type PosthogCoreOptions = {
   // Whether to post events to PostHog in JSON or compressed format
   captureMode?: 'json' | 'form'
   disableGeoip?: boolean
+
+  // For testing purposes only, called at the end of the PostHogCoreStateless constructor
+  __onConstructed?: (posthog: PostHogCoreStateless) => void
 }
 
 export enum PostHogPersistedProperty {

posthog-react-native/src/posthog-rn.ts

@@ -32,6 +32,7 @@ export class PostHog extends PostHogCore {
   private _memoryStorage = new PostHogMemoryStorage()
   private _semiAsyncStorage?: SemiAsyncStorage
   private _appProperties: PostHogCustomAppProperties = {}
+  private _setupPromise?: Promise<void>
 
   static _resetClientCache(): void {
     // NOTE: this method is intended for testing purposes only
@@ -56,7 +57,9 @@ export class PostHog extends PostHogCore {
       console.warn('PostHog.initAsync called twice with the same apiKey. The first instance will be used.')
     }
 
-    return posthog
+    const resolved = await posthog
+    await resolved._setupPromise
+    return resolved
   }
 
   constructor(apiKey: string, options?: PostHogOptions, storage?: SemiAsyncStorage) {
@@ -110,7 +113,7 @@ export class PostHog extends PostHogCore {
       }
     }
 
-    void setupAsync()
+    this._setupPromise = setupAsync()
   }
 
   getPersistedProperty<T>(key: PostHogPersistedProperty): T | undefined {

posthog-react-native/test/posthog.spec.ts

@@ -1,5 +1,9 @@
 import { PostHogPersistedProperty } from 'posthog-core'
 import { PostHog, PostHogCustomAsyncStorage } from '../index'
+import { Linking, AppState, AppStateStatus } from 'react-native'
+
+Linking.getInitialURL = jest.fn(() => Promise.resolve(null))
+AppState.addEventListener = jest.fn()
 
 describe('PostHog React Native', () => {
   let mockStorage: PostHogCustomAsyncStorage
@@ -154,4 +158,169 @@ describe('PostHog React Native', () => {
       expect(posthog.getPersistedProperty(PostHogPersistedProperty.Props)).toEqual(undefined)
     })
   })
+
+  describe('captureNativeAppLifecycleEvents', () => {
+    it('should trigger an Application Installed event', async () => {
+      // arrange
+      const onCapture = jest.fn()
+
+      // act
+      posthog = await PostHog.initAsync('test-install', {
+        customAsyncStorage: mockStorage,
+        flushInterval: 0,
+        captureNativeAppLifecycleEvents: true,
+        __onConstructed: (p) => {
+          p.on('capture', onCapture)
+        },
+        customAppProperties: {
+          $app_build: '1',
+          $app_version: '1.0.0',
+        },
+      })
+
+      // assert
+      expect(onCapture).toHaveBeenCalledTimes(2)
+      expect(onCapture.mock.calls[0][0]).toMatchObject({
+        event: 'Application Installed',
+        properties: {
+          $app_build: '1',
+          $app_version: '1.0.0',
+        },
+      })
+      expect(onCapture.mock.calls[1][0]).toMatchObject({
+        event: 'Application Opened',
+        properties: {
+          $app_build: '1',
+          $app_version: '1.0.0',
+          from_background: false,
+        },
+      })
+    })
+    it('should trigger an Application Updated event', async () => {
+      // arrange
+      const onCapture = jest.fn()
+      posthog = await PostHog.initAsync('test-update', {
+        customAsyncStorage: mockStorage,
+        captureNativeAppLifecycleEvents: true,
+        customAppProperties: {
+          $app_build: '1',
+          $app_version: '1.0.0',
+        },
+      })
+      PostHog._resetClientCache()
+
+      // act
+      posthog = await PostHog.initAsync('test-update', {
+        customAsyncStorage: mockStorage,
+        flushInterval: 0,
+        captureNativeAppLifecycleEvents: true,
+        __onConstructed: (p) => {
+          p.on('capture', onCapture)
+        },
+        customAppProperties: {
+          $app_build: '2',
+          $app_version: '2.0.0',
+        },
+      })
+
+      // assert
+      expect(onCapture).toHaveBeenCalledTimes(2)
+      expect(onCapture.mock.calls[0][0]).toMatchObject({
+        event: 'Application Updated',
+        properties: {
+          $app_build: '2',
+          $app_version: '2.0.0',
+          previous_build: '1',
+          previous_version: '1.0.0',
+        },
+      })
+      expect(onCapture.mock.calls[1][0]).toMatchObject({
+        event: 'Application Opened',
+        properties: {
+          $app_build: '2',
+          $app_version: '2.0.0',
+          from_background: false,
+        },
+      })
+    })
+    it('should only trigger an open event if the build number has not changed', async () => {
+      // arrange
+      Linking.getInitialURL = jest.fn(() => Promise.resolve('https://example.com'))
+      const onCapture = jest.fn()
+      posthog = await PostHog.initAsync('test-open', {
+        customAsyncStorage: mockStorage,
+        captureNativeAppLifecycleEvents: true,
+        customAppProperties: {
+          $app_build: '1',
+          $app_version: '1.0.0',
+        },
+      })
+      PostHog._resetClientCache()
+
+      // act
+      posthog = await PostHog.initAsync('test-open', {
+        customAsyncStorage: mockStorage,
+        flushInterval: 0,
+        captureNativeAppLifecycleEvents: true,
+        __onConstructed: (p) => {
+          p.on('capture', onCapture)
+        },
+        customAppProperties: {
+          $app_build: '1',
+          $app_version: '1.0.0',
+        },
+      })
+
+      // assert
+      expect(onCapture).toHaveBeenCalledTimes(1)
+      expect(onCapture.mock.calls[0][0]).toMatchObject({
+        event: 'Application Opened',
+        properties: {
+          $app_build: '1',
+          $app_version: '1.0.0',
+          from_background: false,
+          url: 'https://example.com',
+        },
+      })
+    })
+
+    it('should track app background and foreground', async () => {
+      // arrange
+      const onCapture = jest.fn()
+      posthog = await PostHog.initAsync('test-change', {
+        customAsyncStorage: mockStorage,
+        captureNativeAppLifecycleEvents: true,
+        __onConstructed: (p) => {
+          p.on('capture', onCapture)
+        },
+        customAppProperties: {
+          $app_build: '1',
+          $app_version: '1.0.0',
+        },
+      })
+      const cb: (state: AppStateStatus) => void = (AppState.addEventListener as jest.Mock).mock.calls[1][1]
+
+      // act
+      cb('background')
+      cb('active')
+
+      // assert
+      expect(onCapture).toHaveBeenCalledTimes(4)
+      expect(onCapture.mock.calls[2][0]).toMatchObject({
+        event: 'Application Backgrounded',
+        properties: {
+          $app_build: '1',
+          $app_version: '1.0.0',
+        },
+      })
+      expect(onCapture.mock.calls[3][0]).toMatchObject({
+        event: 'Application Opened',
+        properties: {
+          $app_build: '1',
+          $app_version: '1.0.0',
+          from_background: true,
+        },
+      })
+    })
+  })
 })