Bug 1816196 - Do not fetch messaging during storage initialization

While debugging a UI test, we found that the messaging feature was being
queried during the storage initialization and acting on the cached value
alone. This could lead us to no longer receiving new messages during the
app lifetime.

For the unit tests, we switched from mocking the entire feature to
mocking just the `FeaturesInterface` as the test was providing
false-positive results. It's better to create a real feature in any case
for the other testing needs.

Co-authored-by: Benjamin Forehand Jr <bennyjr169@gmail.com>

app/src/main/java/org/mozilla/fenix/gleanplumb/NimbusMessagingStorage.kt

@@ -48,7 +48,7 @@ class NimbusMessagingStorage(
     @VisibleForTesting
     internal val malFormedMap = mutableMapOf<String, String>()
     private val logger = Logger("MessagingStorage")
-    private val nimbusFeature = messagingFeature.value()
+    private val nimbusFeature = messagingFeature
     private val customAttributes: JSONObject
         get() = attributeProvider?.getCustomAttributes(context) ?: JSONObject()
 
@@ -56,11 +56,12 @@ class NimbusMessagingStorage(
      * Returns a list of available messages descending sorted by their priority.
      */
     suspend fun getMessages(): List<Message> {
-        val nimbusTriggers = nimbusFeature.triggers
-        val nimbusStyles = nimbusFeature.styles
-        val nimbusActions = nimbusFeature.actions
+        val featureValue = messagingFeature.value()
+        val nimbusTriggers = featureValue.triggers
+        val nimbusStyles = featureValue.styles
+        val nimbusActions = featureValue.actions
 
-        val nimbusMessages = nimbusFeature.messages
+        val nimbusMessages = featureValue.messages
         val defaultStyle = StyleData()
         val storageMetadata = metadataStorage.getMetadata()
 
@@ -96,7 +97,7 @@ class NimbusMessagingStorage(
         } ?: return null
 
         // Check this isn't an experimental message. If not, we can go ahead and return it.
-        if (!isMessageUnderExperiment(message, nimbusFeature.messageUnderExperiment)) {
+        if (!isMessageUnderExperiment(message, nimbusFeature.value().messageUnderExperiment)) {
             return message
         }
         // If the message is under experiment, then we need to record the exposure
@@ -232,7 +233,7 @@ class NimbusMessagingStorage(
     }
 
     @VisibleForTesting
-    internal fun getOnControlBehavior(): ControlMessageBehavior = nimbusFeature.onControl
+    internal fun getOnControlBehavior(): ControlMessageBehavior = nimbusFeature.value().onControl
 
     private suspend fun addMetadata(id: String): Message.Metadata {
         return metadataStorage.addMetadata(

app/src/test/java/org/mozilla/fenix/gleanplumb/NimbusMessagingStorageTest.kt

@@ -4,6 +4,7 @@
 
 package org.mozilla.fenix.gleanplumb
 
+import io.mockk.Called
 import io.mockk.coEvery
 import io.mockk.every
 import io.mockk.mockk
@@ -37,7 +38,6 @@ class NimbusMessagingStorageTest {
     private lateinit var metadataStorage: MessageMetadataStorage
     private lateinit var gleanPlumb: GleanPlumbInterface
     private lateinit var messagingFeature: FeatureHolder<Messaging>
-    private lateinit var messaging: Messaging
     private var malformedWasReported = false
     private val reportMalformedMessage: (String) -> Unit = {
         malformedWasReported = true
@@ -579,6 +579,20 @@ class NimbusMessagingStorageTest {
         assertEquals(message.id, result!!.id)
     }
 
+    @Test
+    fun `WHEN a storage instance is created THEN do not invoke the feature`() = runTest {
+        storage = NimbusMessagingStorage(
+            testContext,
+            metadataStorage,
+            reportMalformedMessage,
+            gleanPlumb,
+            messagingFeature,
+        )
+
+        // We should not be using the feature holder until getMessages is called.
+        verify { messagingFeature wasNot Called }
+    }
+
     private fun createMessageData(
         action: String = "action-1",
         style: String = "style-1",
@@ -603,16 +617,18 @@ class NimbusMessagingStorageTest {
             "malformed" to createMessageData(action = "malformed-action"),
         ),
     ): FeatureHolder<Messaging> {
-        val messagingFeature: FeatureHolder<Messaging> = mockk(relaxed = true)
-        messaging = Messaging(
+        val messaging = Messaging(
             actions = actions,
             triggers = triggers,
             messages = messages,
             styles = styles,
         )
-        every { messagingFeature.value() } returns messaging
+        val messagingFeature = FeatureHolder({ mockk(relaxed = true) }, "messaging") {
+            messaging
+        }
+        messagingFeature.withCachedValue(messaging)
 
-        return messagingFeature
+        return spyk(messagingFeature)
     }
 
     private fun createStyle(priority: Int = 1, maxDisplayCount: Int = 5): StyleData {