add a test for it

library/src/androidTest/java/org/xmtp/android/library/GroupTest.kt

@@ -1,5 +1,6 @@
 package org.xmtp.android.library
 
+import android.util.Log
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.platform.app.InstrumentationRegistry
 import app.cash.turbine.test
@@ -28,6 +29,9 @@ import org.xmtp.proto.mls.message.contents.TranscriptMessages
 import uniffi.xmtpv3.org.xmtp.android.library.libxmtp.GroupPermissionPreconfiguration
 import uniffi.xmtpv3.org.xmtp.android.library.libxmtp.PermissionOption
 import java.security.SecureRandom
+import java.util.Date
+import kotlin.time.Duration.Companion.nanoseconds
+import kotlin.time.DurationUnit
 
 @RunWith(AndroidJUnit4::class)
 class GroupTest {
@@ -545,6 +549,31 @@ class GroupTest {
         assertEquals(sameGroup.messages(deliveryStatus = MessageDeliveryStatus.PUBLISHED).size, 2)
     }
 
+    @Test
+    fun testCanListGroupMessagesAfter() {
+        val group = runBlocking { boClient.conversations.newGroup(listOf(alix.walletAddress)) }
+        runBlocking {
+            group.send("howdy")
+            group.send("gm")
+        }
+        Thread.sleep(1000)
+        val time = Date()
+        assertEquals(group.messages().size, 3)
+        assertEquals(group.messages(after = time).size, 0)
+        runBlocking {
+            group.send("howdy")
+            group.send("gm")
+        }
+        assertEquals(group.messages().size, 5)
+        assertEquals(group.messages(after = time).size, 2)
+
+        runBlocking { alixClient.conversations.syncConversations() }
+        val sameGroup = runBlocking { alixClient.conversations.listGroups().last() }
+        runBlocking { sameGroup.sync() }
+        assertEquals(sameGroup.messages().size, 5)
+        assertEquals(sameGroup.messages(after = time).size, 2)
+    }
+
     @Test
     fun testCanSendContentTypesToGroup() {
         Client.register(codec = ReactionCodec())