Adds test and some refinements.

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/kotlinSerialization/MessageKSerializer.kt

@@ -90,6 +90,10 @@ object MessageKSerializer : KSerializer<Message> {
                     is CountMessage -> {
                         add(CountResultKSerializer.serializeToElement(value.result))
                     }
+
+                    is EoseMessage -> {
+                        add(JsonPrimitive(value.subId))
+                    }
                 }
             }
         jsonEncoder.encodeJsonElement(element)

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/relay/client/accessories/RelayLogger.kt

@@ -25,6 +25,7 @@ import com.vitorpamplona.quartz.nip01Core.relay.client.listeners.IRelayClientLis
 import com.vitorpamplona.quartz.nip01Core.relay.client.single.IRelayClient
 import com.vitorpamplona.quartz.nip01Core.relay.commands.toClient.AuthMessage
 import com.vitorpamplona.quartz.nip01Core.relay.commands.toClient.ClosedMessage
+import com.vitorpamplona.quartz.nip01Core.relay.commands.toClient.CountMessage
 import com.vitorpamplona.quartz.nip01Core.relay.commands.toClient.EoseMessage
 import com.vitorpamplona.quartz.nip01Core.relay.commands.toClient.EventMessage
 import com.vitorpamplona.quartz.nip01Core.relay.commands.toClient.Message
@@ -62,6 +63,7 @@ class RelayLogger(
                     is OkMessage -> if (debugReceiving) Log.d(logTag, "OK: ${msg.eventId} ${msg.success} ${msg.message}")
                     is AuthMessage -> if (debugReceiving) Log.d(logTag, "Auth: ${msg.challenge}")
                     is NotifyMessage -> if (debugReceiving) Log.d(logTag, "Notify: ${msg.message}")
+                    is CountMessage -> if (debugReceiving) Log.d(logTag, "Count: ${msg.result.count} approx: ${msg.result.approximate}")
                     is ClosedMessage -> Log.w(logTag, "Closed: ${msg.subId} ${msg.message}")
                 }
             }

quartz/src/jvmAndroid/kotlin/com/vitorpamplona/quartz/nip01Core/relay/commands/toClient/CountResultDeserializer.kt

@@ -26,8 +26,8 @@ class CountResultDeserializer {
     companion object {
         fun fromJson(jsonObject: JsonNode): CountResult =
             CountResult(
-                count = jsonObject.get("count").asInt(),
-                approximate = jsonObject.get("approximate").asBoolean(),
+                count = jsonObject.get("count")?.asInt() ?: 0,
+                approximate = jsonObject.get("approximate")?.asBoolean() ?: false,
             )
     }
 }

quartz/src/jvmAndroid/kotlin/com/vitorpamplona/quartz/nip01Core/relay/commands/toClient/MessageSerializer.kt

@@ -72,8 +72,8 @@ class MessageSerializer : StdSerializer<Message>(Message::class.java) {
                 countSerializer.serialize(msg.result, gen, provider)
             }
 
-            else -> {
-                null
+            is EoseMessage -> {
+                gen.writeString(msg.subId)
             }
         }
 

quartz/src/jvmAndroidTest/kotlin/com/vitorpamplona/quartz/nip01Core/relay/NostrClientQueryCountTest.kt

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip01Core.relay
+
+import com.vitorpamplona.quartz.nip01Core.relay.client.NostrClient
+import com.vitorpamplona.quartz.nip01Core.relay.client.accessories.queryCountSuspend
+import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.normalizeRelayUrl
+import junit.framework.TestCase.assertTrue
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.runBlocking
+import kotlin.test.Test
+
+class NostrClientQueryCountTest : BaseNostrClientTest() {
+    val fiatjaf = "wss://pyramid.fiatjaf.com".normalizeRelayUrl()
+    val utxo = "wss://news.utxo.one".normalizeRelayUrl()
+
+    val metadata = Filter(kinds = listOf(0))
+    val outboxRelays = Filter(kinds = listOf(10002))
+
+    @Test
+    fun testQueryCountSuspend() =
+        runBlocking {
+            val appScope = CoroutineScope(Dispatchers.Default + SupervisorJob())
+            val client = NostrClient(socketBuilder, appScope)
+
+            val result = client.queryCountSuspend(relay = fiatjaf, filter = metadata)
+
+            assertTrue((result?.count ?: 0) > 1)
+
+            client.disconnect()
+            appScope.cancel()
+        }
+
+    @Test
+    fun testQueryCountSuspendAllEvents() =
+        runBlocking {
+            val appScope = CoroutineScope(Dispatchers.Default + SupervisorJob())
+            val client = NostrClient(socketBuilder, appScope)
+
+            val result = client.queryCountSuspend(relay = fiatjaf, filter = Filter())
+
+            assertTrue((result?.count ?: 0) > 1)
+
+            client.disconnect()
+            appScope.cancel()
+        }
+
+    @Test
+    fun testQueryCountSuspendMultipleRelays() =
+        runBlocking {
+            val appScope = CoroutineScope(Dispatchers.Default + SupervisorJob())
+            val client = NostrClient(socketBuilder, appScope)
+
+            val result =
+                client.queryCountSuspend(
+                    filters =
+                        mapOf(
+                            fiatjaf to listOf(metadata, outboxRelays),
+                            utxo to listOf(metadata, outboxRelays),
+                        ),
+                )
+
+            result.forEach { url, result ->
+                println("${url.url}: ${result.count}")
+                assertTrue(result.count > 1)
+            }
+
+            client.disconnect()
+            appScope.cancel()
+        }
+}