Respect limit in message pagination (#103)

* add api client with grpc kotlin

* respect the limit for pagination

* fix the lint issue

Author: nplasterer

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

@@ -128,14 +128,17 @@ class LocalInstrumentedTest {
         date.time = date.time - 5000
         convo.send(text = "10 seconds ago", sentAt = date)
         Thread.sleep(5000)
+        convo.send(text = "now first")
         convo.send(text = "now")
         val messages = convo.messages()
-        assertEquals(2, messages.size)
+        assertEquals(3, messages.size)
+        val messagesLimit = convo.messages(limit = 2)
+        assertEquals(2, messagesLimit.size)
         val nowMessage = messages[0]
         assertEquals("now", nowMessage.body)
-        val messages2 = convo.messages(before = nowMessage.sent)
+        val messages2 = convo.messages(limit = 1, before = nowMessage.sent)
         val tenSecondsAgoMessage = messages2[0]
-        assertEquals("10 seconds ago", tenSecondsAgoMessage.body)
+        assertEquals("now first", tenSecondsAgoMessage.body)
         val messages3 = convo.messages(after = tenSecondsAgoMessage.sent)
         val nowMessage2 = messages3[0]
         assertEquals("now", nowMessage2.body)

library/src/main/java/org/xmtp/android/library/ApiClient.kt

@@ -123,14 +123,18 @@ data class GRPCApiClient(
     }
 
     override suspend fun envelopes(topic: String, pagination: Pagination?): List<Envelope> {
-        val envelopes: MutableList<Envelope> = mutableListOf()
+        var envelopes: MutableList<Envelope> = mutableListOf()
         var hasNextPage = true
         var cursor: Cursor? = null
         while (hasNextPage) {
             val response = query(topic = topic, pagination = pagination, cursor = cursor)
             envelopes.addAll(response.envelopesList)
             cursor = response.pagingInfo.cursor
             hasNextPage = response.envelopesList.isNotEmpty() && response.pagingInfo.hasCursor()
+            if (pagination?.limit != null && envelopes.size >= pagination.limit) {
+                envelopes = envelopes.take(pagination.limit).toMutableList()
+                break
+            }
         }
         return envelopes
     }