From 318f5d66289a04cb03b6971e3152683ce2ef81c1 Mon Sep 17 00:00:00 2001
From: jorgesanfz <155391333+jorgesanfz@users.noreply.github.com>
Date: Sun, 9 Jun 2024 14:14:58 +0200
Subject: [PATCH] fix first observe response not being handled (#195)

---
 lib/src/coap_client.dart                  | 5 +----
 lib/src/coap_observe_client_relation.dart | 8 ++++++++
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/lib/src/coap_client.dart b/lib/src/coap_client.dart
index 0c8f8f4d..8a47a521 100644
--- a/lib/src/coap_client.dart
+++ b/lib/src/coap_client.dart
@@ -525,10 +525,7 @@ class CoapClient {
       },
     );
     final relation = CoapObserveClientRelation(request, responseStream);
-    final resp = await _waitForResponse(request, responseStream);
-    if (!resp.hasOption<ObserveOption>()) {
-      relation.isCancelled = true;
-    }
+    relation.checkObserve();
     isObserving = true;
     return relation;
   }
diff --git a/lib/src/coap_observe_client_relation.dart b/lib/src/coap_observe_client_relation.dart
index 0d1db0c7..79b268c9 100644
--- a/lib/src/coap_observe_client_relation.dart
+++ b/lib/src/coap_observe_client_relation.dart
@@ -55,6 +55,14 @@ class CoapObserveClientRelation extends Stream<CoapResponse> {
     return requestToken.equals(responseToken);
   }
 
+  void checkObserve() {
+    _filteredStream.first.then((resp) {
+      if (!resp.hasOption<ObserveOption>()) {
+        isCancelled = true;
+      }
+    });
+  }
+
   bool _cancelled = false;
 
   /// Cancelled