WIP: Bug 2003370 - Use and react to Gecko preferences stored values

CHANGELOG.md

@@ -1,4 +1,6 @@
 # v148.0 (In progress)
+### Nimbus
+* Adds `PreviousState` on `ExperimentEnrollment` when it is of type `EnrollmentStatus::Enrolled` and getters and setters. `PreviousState::GeckoPref` is added to support previous states for Gecko pref experiments.
 
 [Full Changelog](In progress)
 

components/nimbus/android/src/main/java/org/mozilla/experiments/nimbus/Nimbus.kt

@@ -44,6 +44,7 @@ import org.mozilla.experiments.nimbus.internal.NimbusClient
 import org.mozilla.experiments.nimbus.internal.NimbusClientInterface
 import org.mozilla.experiments.nimbus.internal.NimbusException
 import org.mozilla.experiments.nimbus.internal.PrefUnenrollReason
+import org.mozilla.experiments.nimbus.internal.PreviousState
 import org.mozilla.experiments.nimbus.internal.RecordedContext
 import java.io.File
 import java.io.IOException
@@ -438,6 +439,18 @@ open class Nimbus(
         return nimbusClient.unenrollForGeckoPref(geckoPrefState, prefUnenrollReason)
     }
 
+    override fun registerPreviousGeckoPrefStates(geckoPrefStates: List<GeckoPrefState>) {
+        dbScope.launch {
+            withCatchAll("registerPreviousGeckoPrefStates") {
+                nimbusClient.registerPreviousGeckoPrefStates(geckoPrefStates)
+            }
+        }
+    }
+
+    override fun getPreviousState(experimentSlug: String): PreviousState? {
+        return nimbusClient.getPreviousState(experimentSlug)
+    }
+
     @WorkerThread
     @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
     internal fun optOutOnThisThread(experimentId: String) = withCatchAll("optOut") {

components/nimbus/android/src/main/java/org/mozilla/experiments/nimbus/NimbusInterface.kt

@@ -17,6 +17,7 @@ import org.mozilla.experiments.nimbus.internal.EnrollmentChangeEvent
 import org.mozilla.experiments.nimbus.internal.ExperimentBranch
 import org.mozilla.experiments.nimbus.internal.GeckoPrefState
 import org.mozilla.experiments.nimbus.internal.PrefUnenrollReason
+import org.mozilla.experiments.nimbus.internal.PreviousState
 import java.time.Duration
 import java.util.concurrent.TimeUnit
 
@@ -191,6 +192,26 @@ interface NimbusInterface : FeaturesInterface, NimbusMessagingInterface, NimbusE
         prefUnenrollReason: PrefUnenrollReason,
     ): List<EnrollmentChangeEvent> = listOf()
 
+    /**
+     * Add the original Gecko pref values as a previous state on each involved enrollment.
+     *
+     * @param geckoPrefStates The list of items that should have their enrollment state updated with
+     * original Gecko pref previous state information.
+     */
+    fun registerPreviousGeckoPrefStates(
+        geckoPrefStates: List<GeckoPrefState>,
+    ) = Unit
+
+    /**
+     * Retrieves a previous state, if available on an enrolled experiment, from a given slug.
+     *
+     * @param experimentSlug The slug of the experiment.
+     * @return The previous state of the given slug. Will return null if not available or invalid slug.
+     */
+    fun getPreviousState(
+        experimentSlug: String,
+    ): PreviousState? = null
+
     /**
      *  Reset internal state in response to application-level telemetry reset.
      *  Consumers should call this method when the user resets the telemetry state of the

components/nimbus/android/src/test/java/org/mozilla/experiments/nimbus/NimbusTests.kt

@@ -5,6 +5,7 @@
 package org.mozilla.experiments.nimbus
 
 import android.content.Context
+import android.os.Looper
 import android.util.Log
 import androidx.test.core.app.ApplicationProvider
 import kotlinx.coroutines.CancellationException
@@ -42,12 +43,17 @@ import org.mozilla.experiments.nimbus.internal.GeckoPrefHandler
 import org.mozilla.experiments.nimbus.internal.GeckoPrefState
 import org.mozilla.experiments.nimbus.internal.JsonObject
 import org.mozilla.experiments.nimbus.internal.NimbusException
+import org.mozilla.experiments.nimbus.internal.OriginalGeckoPref
 import org.mozilla.experiments.nimbus.internal.PrefBranch
+import org.mozilla.experiments.nimbus.internal.PrefEnrollmentData
 import org.mozilla.experiments.nimbus.internal.PrefUnenrollReason
+import org.mozilla.experiments.nimbus.internal.PreviousGeckoPrefState
+import org.mozilla.experiments.nimbus.internal.PreviousState
 import org.mozilla.experiments.nimbus.internal.RecordedContext
 import org.mozilla.experiments.nimbus.internal.getCalculatedAttributes
 import org.mozilla.experiments.nimbus.internal.validateEventQueries
 import org.robolectric.RobolectricTestRunner
+import org.robolectric.Shadows.shadowOf
 import java.io.File
 import java.util.Calendar
 import java.util.concurrent.Executors
@@ -849,12 +855,13 @@ class NimbusTests {
                 "number" to GeckoPrefState(
                     geckoPref = GeckoPref("pref.number", PrefBranch.DEFAULT),
                     geckoValue = "1",
-                    enrollmentValue = null,
+                    enrollmentValue = PrefEnrollmentData("test-experiment", "42", "about_welcome", "number"),
                     isUserSet = false,
                 ),
             ),
         ),
         var setValues: List<GeckoPrefState>? = null,
+        var originalGeckoPrefValues: List<OriginalGeckoPref>? = null,
     ) : GeckoPrefHandler {
         override fun getPrefsWithState(): Map<String, Map<String, GeckoPrefState>> {
             return internalMap
@@ -863,6 +870,10 @@ class NimbusTests {
         override fun setGeckoPrefsState(newPrefsState: List<GeckoPrefState>) {
             setValues = newPrefsState
         }
+
+        override fun setGeckoPrefsOriginalValues(originalGeckoPrefs: List<OriginalGeckoPref>) {
+            originalGeckoPrefValues = originalGeckoPrefs
+        }
     }
 
     @Test
@@ -884,6 +895,21 @@ class NimbusTests {
         assertEquals("42", handler.setValues?.get(0)?.enrollmentValue?.prefValue)
     }
 
+    @Test
+    fun `GeckoPrefHandler setGeckoPrefsOriginalValues function`() {
+      val handler = TestGeckoPrefHandler()
+      val originalValues = listOf(
+          OriginalGeckoPref(
+              pref = "pref.number",
+              branch = PrefBranch.DEFAULT,
+              value = "1",
+          ),
+      )
+      handler.setGeckoPrefsOriginalValues(originalValues)
+      assertEquals(1, handler.originalGeckoPrefValues?.size)
+      assertEquals("pref.number", handler.originalGeckoPrefValues?.get(0)?.pref)
+    }
+
     @Test
     fun `unenroll for gecko pref functions`() {
         val handler = TestGeckoPrefHandler()
@@ -911,6 +937,36 @@ class NimbusTests {
         assertEquals(EnrollmentChangeEventType.DISQUALIFICATION, events[0].change)
         assertEquals(0, handler.setValues?.size)
     }
+
+    @Test
+    fun `register previous gecko states and check values`() {
+        val handler = TestGeckoPrefHandler()
+
+        val nimbus = createNimbus(geckoPrefHandler = handler)
+
+        suspend fun getString(): String {
+            return testExperimentsJsonString(appInfo, packageName)
+        }
+
+        val job = nimbus.applyLocalExperiments(::getString)
+        runBlocking {
+            job.join()
+        }
+
+        assertEquals(1, handler.setValues?.size)
+        assertEquals("42", handler.setValues?.get(0)?.enrollmentValue?.prefValue)
+
+        nimbus.registerPreviousGeckoPrefStates(handler.setValues!!)
+        shadowOf(Looper.getMainLooper()).idle()
+
+        val previousState = nimbus.getPreviousState("test-experiment")
+        shadowOf(Looper.getMainLooper()).idle()
+
+        assertNotNull(previousState)
+        val geckoPreviousState = previousState as PreviousState.GeckoPref
+        assertEquals("1", geckoPreviousState!!.v1.originalValues[0].value)
+        assertEquals("pref.number", geckoPreviousState!!.v1.originalValues[0].pref)
+    }
 }
 
 // Mocking utilities, from mozilla.components.support.test