Code review:

- apply exception-class fallback to connect() too
- dedup message construction

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip01Core/relay/client/single/basic/BasicRelayClient.kt

@@ -103,7 +103,7 @@ open class BasicRelayClient(
             socket?.connect()
         } catch (e: Exception) {
             if (e is CancellationException) throw e
-            listener.onCannotConnect(this, "Error when trying to connect: ${e.message}")
+            listener.onCannotConnect(this, "Error when trying to connect: ${e.message ?: e::class.simpleName}")
             listener.onDisconnected(this)
             dontTryAgainForALongTime()
             markConnectionAsClosed()
@@ -154,7 +154,9 @@ open class BasicRelayClient(
             } else {
                 socket?.disconnect()
 
+                // suppression rules below must match the raw message; displayMsg is for listener output only
                 val msg = t.message
+                val displayMsg = msg ?: t::class.simpleName
 
                 // checks if this is an actual failure. Closing the socket generates an onFailure as well.
                 // ignore tor errors.
@@ -167,9 +169,9 @@ open class BasicRelayClient(
                     )
                 ) {
                     if (code != null || response != null) {
-                        listener.onCannotConnect(this@BasicRelayClient, "Server Misconfigured. Response: $code $response. Exception: ${t.message ?: t::class.simpleName}")
+                        listener.onCannotConnect(this@BasicRelayClient, "Server Misconfigured. Response: $code $response. Exception: $displayMsg")
                     } else {
-                        listener.onCannotConnect(this@BasicRelayClient, "WebSocket Failure: ${t.message ?: t::class.simpleName}")
+                        listener.onCannotConnect(this@BasicRelayClient, "WebSocket Failure: $displayMsg")
                     }
                 } else {
                     // ignore local disconnect requests and tor errors

quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip01Core/relay/client/single/basic/BasicRelayClientTest.kt

@@ -66,10 +66,14 @@ class BasicRelayClientTest {
 
     private class MessagelessException : Exception()
 
-    private fun connectAndCapture(
-        builder: FakeWebsocketBuilder,
-        listener: RecordingConnectionListener,
-    ): WebSocketListener {
+    private data class Harness(
+        val socketListener: WebSocketListener,
+        val connectionListener: RecordingConnectionListener,
+    )
+
+    private fun connectAndCapture(): Harness {
+        val builder = FakeWebsocketBuilder()
+        val listener = RecordingConnectionListener()
         val client =
             BasicRelayClient(
                 NormalizedRelayUrl("wss://relay.example.com/"),
@@ -79,15 +83,14 @@ class BasicRelayClientTest {
         client.connect()
         val socketListener = builder.capturedListener
         assertNotNull(socketListener)
-        return socketListener
+        return Harness(socketListener, listener)
     }
 
     @Test
     fun onFailureWithNullMessageReportsExceptionClassName() {
-        val builder = FakeWebsocketBuilder()
-        val listener = RecordingConnectionListener()
+        val (socket, listener) = connectAndCapture()
 
-        connectAndCapture(builder, listener).onFailure(MessagelessException(), null, null)
+        socket.onFailure(MessagelessException(), null, null)
 
         assertEquals(
             listOf("WebSocket Failure: MessagelessException"),
@@ -97,10 +100,9 @@ class BasicRelayClientTest {
 
     @Test
     fun onFailureWithMessageKeepsExistingFormat() {
-        val builder = FakeWebsocketBuilder()
-        val listener = RecordingConnectionListener()
+        val (socket, listener) = connectAndCapture()
 
-        connectAndCapture(builder, listener).onFailure(Exception("Connection reset"), null, null)
+        socket.onFailure(Exception("Connection reset"), null, null)
 
         assertEquals(
             listOf("WebSocket Failure: Connection reset"),
@@ -110,10 +112,9 @@ class BasicRelayClientTest {
 
     @Test
     fun serverMisconfiguredWithNullMessageReportsExceptionClassName() {
-        val builder = FakeWebsocketBuilder()
-        val listener = RecordingConnectionListener()
+        val (socket, listener) = connectAndCapture()
 
-        connectAndCapture(builder, listener).onFailure(MessagelessException(), 200, "OK")
+        socket.onFailure(MessagelessException(), 200, "OK")
 
         assertEquals(
             listOf("Server Misconfigured. Response: 200 OK. Exception: MessagelessException"),