added simple websocket test

- bump to v0.21.1

relay-tester/test.go

@@ -291,6 +291,11 @@ func (s *TestSuite) registerTests() {
 			Required: true,
 			Func:     testSupportsEose,
 		},
+		{
+			Name:     "Subscription receives event after ping period",
+			Required: true,
+			Func:     testSubscriptionReceivesEventAfterPingPeriod,
+		},
 		{
 			Name:     "Closes complete subscriptions after EOSE",
 			Required: false,
@@ -420,6 +425,20 @@ func (s *TestSuite) GetResults() map[string]TestResult {
 	return s.results
 }
 
+// ListTests returns a list of all test names in execution order.
+func (s *TestSuite) ListTests() []string {
+	return s.order
+}
+
+// GetTestNames returns all registered test names as a map (name -> required).
+func (s *TestSuite) GetTestNames() map[string]bool {
+	result := make(map[string]bool)
+	for name, tc := range s.tests {
+		result[name] = tc.Required
+	}
+	return result
+}
+
 // FormatJSON formats results as JSON.
 func FormatJSON(results []TestResult) (output string, err error) {
 	var data []byte