For #13229 - Cache deviceId for reuse

app/src/main/java/org/mozilla/fenix/components/metrics/LeanplumMetricsService.kt

@@ -5,7 +5,9 @@
 package org.mozilla.fenix.components.metrics
 
 import android.app.Application
+import android.content.Context.MODE_PRIVATE
 import android.util.Log
+import androidx.annotation.VisibleForTesting
 import com.leanplum.Leanplum
 import com.leanplum.LeanplumActivityHelper
 import com.leanplum.annotations.Parser
@@ -44,7 +46,10 @@ private val Event.name: String?
         else -> ""
     }
 
-class LeanplumMetricsService(private val application: Application) : MetricsService {
+class LeanplumMetricsService(
+    private val application: Application,
+    private val deviceIdGenerator: () -> String = { randomUUID().toString() }
+) : MetricsService {
     val scope = CoroutineScope(Dispatchers.IO)
     var leanplumJob: Job? = null
 
@@ -68,13 +73,27 @@ class LeanplumMetricsService(private val application: Application) : MetricsServ
     override val type = MetricServiceType.Marketing
     private val token = Token(LeanplumId, LeanplumToken)
 
+    private val preferences = application.getSharedPreferences(PREFERENCE_NAME, MODE_PRIVATE)
+
+    @VisibleForTesting
+    internal val deviceId by lazy {
+        var deviceId = preferences.getString(DEVICE_ID_KEY, null)
+
+        if (deviceId == null) {
+            deviceId = deviceIdGenerator.invoke()
+            preferences.edit().putString(DEVICE_ID_KEY, deviceId).apply()
+        }
+
+        deviceId
+    }
+
     override fun start() {
 
         if (!application.settings().isMarketingTelemetryEnabled) return
 
         Leanplum.setIsTestModeEnabled(false)
         Leanplum.setApplicationContext(application)
-        Leanplum.setDeviceId(randomUUID().toString())
+        Leanplum.setDeviceId(deviceId)
         Parser.parseVariables(application)
 
         leanplumJob = scope.launch {
@@ -197,5 +216,8 @@ class LeanplumMetricsService(private val application: Application) : MetricsServ
             "ara", // Arabic
             "jpn" // Japanese
         )
+
+        private const val PREFERENCE_NAME = "LEANPLUM_PREFERENCES"
+        private const val DEVICE_ID_KEY = "LP_DEVICE_ID"
     }
 }

app/src/test/java/org/mozilla/fenix/components/metrics/LeanplumMetricsServiceTest.kt

@@ -0,0 +1,42 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.components.metrics
+
+import android.content.Context.MODE_PRIVATE
+import mozilla.components.support.test.robolectric.testContext
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mozilla.fenix.ext.application
+import org.mozilla.fenix.helpers.FenixRobolectricTestRunner
+
+@RunWith(FenixRobolectricTestRunner::class)
+class LeanplumMetricsServiceTest {
+    @Test
+    fun `deviceId is only generated on first run`() {
+        var callCount = 0
+        val idGenerator = {
+            callCount++
+            "TEST_DEVICE_ID"
+        }
+
+        val sharedPreferences = testContext.application.getSharedPreferences(
+            "LEANPLUM_PREFERENCES",
+            MODE_PRIVATE
+        )
+
+        assertNull(sharedPreferences.getString("LP_DEVICE_ID", null))
+
+        val leanplumMetricService = LeanplumMetricsService(testContext.application, idGenerator)
+        assertEquals("TEST_DEVICE_ID", leanplumMetricService.deviceId)
+
+        val leanplumMetricService2 = LeanplumMetricsService(testContext.application, idGenerator)
+        assertEquals("TEST_DEVICE_ID", leanplumMetricService2.deviceId)
+        assertEquals(1, callCount)
+
+        assertEquals("TEST_DEVICE_ID", sharedPreferences.getString("LP_DEVICE_ID", ""))
+    }
+}