add HTTP header OneSignal-Install-Id

OneSignal-Install-Id is a UUIDv4 locally generated on the device and
added to as an HTTP Header to all calls made to OneSignal's backend.
This allows the OneSignal's backend know where traffic is coming
from, no matter if the SubscriptionId or OneSignalId changes or isn't
available yet.

State for the new installId is encapsulated in a new InstallIdService
class, where it handles generating the id and persisting it. Tests
were also added to ensure the persisting behavior works as expected.

Author: jkasten2

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/CoreModule.kt

@@ -13,7 +13,9 @@ import com.onesignal.core.internal.config.impl.ConfigModelStoreListener
 import com.onesignal.core.internal.database.IDatabaseProvider
 import com.onesignal.core.internal.database.impl.DatabaseProvider
 import com.onesignal.core.internal.device.IDeviceService
+import com.onesignal.core.internal.device.IInstallIdService
 import com.onesignal.core.internal.device.impl.DeviceService
+import com.onesignal.core.internal.device.impl.InstallIdService
 import com.onesignal.core.internal.http.IHttpClient
 import com.onesignal.core.internal.http.impl.HttpClient
 import com.onesignal.core.internal.http.impl.HttpConnectionFactory
@@ -53,6 +55,7 @@ internal class CoreModule : IModule {
         builder.register<Time>().provides<ITime>()
         builder.register<DatabaseProvider>().provides<IDatabaseProvider>()
         builder.register<StartupService>().provides<StartupService>()
+        builder.register<InstallIdService>().provides<IInstallIdService>()
 
         // Params (Config)
         builder.register<ConfigModelStore>().provides<ConfigModelStore>()

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/device/IInstallIdService.kt

@@ -0,0 +1,11 @@
+package com.onesignal.core.internal.device
+
+import java.util.UUID
+
+interface IInstallIdService {
+    /**
+     * WARNING: This may do disk I/O on the first call, so never call this from
+     * the main thread.
+     */
+    suspend fun getId(): UUID
+}

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/device/impl/InstallIdService.kt

@@ -0,0 +1,35 @@
+package com.onesignal.core.internal.device.impl
+
+import com.onesignal.core.internal.device.IInstallIdService
+import com.onesignal.core.internal.preferences.IPreferencesService
+import com.onesignal.core.internal.preferences.PreferenceOneSignalKeys
+import com.onesignal.core.internal.preferences.PreferenceStores
+import java.util.UUID
+
+/**
+ * Manages a persistent UUIDv4, generated once when app is first opened.
+ * Value is for a HTTP header, OneSignal-Install-Id, added on all calls made
+ * to OneSignal's backend. This allows the OneSignal's backend know where
+ * traffic is coming from, no matter if the SubscriptionId or OneSignalId
+ * changes or isn't available yet.
+ */
+internal class InstallIdService(
+    private val _prefs: IPreferencesService,
+) : IInstallIdService {
+    private val currentId: UUID by lazy {
+        val idFromPrefs = _prefs.getString(PreferenceStores.ONESIGNAL, PreferenceOneSignalKeys.PREFS_OS_INSTALL_ID)
+        if (idFromPrefs != null) {
+            UUID.fromString(idFromPrefs)
+        } else {
+            val newId = UUID.randomUUID()
+            _prefs.saveString(PreferenceStores.ONESIGNAL, PreferenceOneSignalKeys.PREFS_OS_INSTALL_ID, newId.toString())
+            newId
+        }
+    }
+
+    /**
+     * WARNING: This may do disk I/O on the first call, so never call this from
+     * the main thread. Disk I/O is done inside of "currentId by lazy".
+     */
+    override suspend fun getId() = currentId
+}

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/http/impl/HttpClient.kt

@@ -6,6 +6,7 @@ import com.onesignal.common.JSONUtils
 import com.onesignal.common.OneSignalUtils
 import com.onesignal.common.OneSignalWrapper
 import com.onesignal.core.internal.config.ConfigModelStore
+import com.onesignal.core.internal.device.IInstallIdService
 import com.onesignal.core.internal.http.HttpResponse
 import com.onesignal.core.internal.http.IHttpClient
 import com.onesignal.core.internal.preferences.IPreferencesService
@@ -32,6 +33,7 @@ internal class HttpClient(
     private val _prefs: IPreferencesService,
     private val _configModelStore: ConfigModelStore,
     private val _time: ITime,
+    private val _installIdService: IInstallIdService,
 ) : IHttpClient {
     /**
      * Delay making network requests until we reach this time.
@@ -149,6 +151,8 @@ internal class HttpClient(
                         con.setRequestProperty("OneSignal-Subscription-Id", subscriptionId)
                     }
 
+                    con.setRequestProperty("OneSignal-Install-Id", _installIdService.getId().toString())
+
                     if (jsonBody != null) {
                         con.doInput = true
                     }

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/preferences/IPreferencesService.kt

@@ -215,6 +215,13 @@ object PreferenceOneSignalKeys {
      */
     const val PREFS_OS_ETAG_PREFIX = "PREFS_OS_ETAG_PREFIX_"
 
+    /**
+     * (String) A install id, a UUIDv4 generated once when app is first opened.
+     * Value is for a HTTP header, OneSignal-Install-Id, added on all calls
+     * made to OneSignal's backend.
+     */
+    const val PREFS_OS_INSTALL_ID = "PREFS_OS_INSTALL_ID"
+
     /**
      * (String) A prefix key for retrieving the response for a given HTTP GET cache key. The cache
      * key should be appended to this prefix.

OneSignalSDK/onesignal/core/src/test/java/com/onesignal/core/internal/device/InstallIdServiceTests.kt

@@ -0,0 +1,36 @@
+package com.onesignal.core.internal.device
+
+import com.onesignal.core.internal.device.impl.InstallIdService
+import com.onesignal.mocks.MockPreferencesService
+import io.kotest.core.spec.style.FunSpec
+import io.kotest.matchers.shouldBe
+
+class InstallIdServiceTests : FunSpec({
+    test("2 calls result in the same value") {
+        // Given
+        val service = InstallIdService(MockPreferencesService())
+
+        // When
+        val value1 = service.getId()
+        val value2 = service.getId()
+
+        // Then
+        value1 shouldBe value2
+    }
+
+    // Real world scenario we are testing is if we cold restart the app we get
+    // the same value
+    test("reads from shared prefs") {
+        // Given
+        val sharedPrefs = MockPreferencesService()
+
+        // When
+        val service1 = InstallIdService(sharedPrefs)
+        val value1 = service1.getId()
+        val service2 = InstallIdService(sharedPrefs)
+        val value2 = service2.getId()
+
+        // Then
+        value1 shouldBe value2
+    }
+})

OneSignalSDK/onesignal/core/src/test/java/com/onesignal/core/internal/http/HttpClientTests.kt

@@ -1,6 +1,7 @@
 package com.onesignal.core.internal.http
 
 import com.onesignal.common.OneSignalUtils
+import com.onesignal.core.internal.device.impl.InstallIdService
 import com.onesignal.core.internal.http.impl.HttpClient
 import com.onesignal.core.internal.time.impl.Time
 import com.onesignal.debug.LogLevel
@@ -21,7 +22,7 @@ class Mocks {
     internal val response = MockHttpConnectionFactory.MockResponse()
     internal val factory = MockHttpConnectionFactory(response)
     internal val httpClient by lazy {
-        HttpClient(factory, MockPreferencesService(), mockConfigModel, Time())
+        HttpClient(factory, MockPreferencesService(), mockConfigModel, Time(), InstallIdService(MockPreferencesService()))
     }
 }